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After the most wonderful and darkest time of the year, the new year starts with firework that is launched from the most beautiful



by civil engineering. Also in the start of 2018 the Dutch famous coast protection structures were tested due to the heavy weather conditions. It was the first time that all the Dutch sea blocks closed at the same time without failing. But there is always room for improvement,



renovation because the new year is challenging us with climate change and a growing economy which leads to more traffic jams, housing problems, higher sea level and extreme weather. The civil engineering world is never

finished due to a changing world with innovations and new problems. In this edition, you will read how the new interchange near Joure is built with the innovative beams of Haitsma Beton and you will read about a sustainable roundabout, the first roundabout with the cradle-to-cradle concept. In our study association, we are facing also some changes.The new board and the new programme coordinator CE will introduce themselves. Even a new committee within our study association, the education committee, will introduce themselves in this edition. As a new member of ConcepTueel I wish you lots of fun reading the first edition of 2018 and a happy civil engineering new year. Floris Couwenberg



COLOFON Editorial adress ConcepT Universiteit Twente Kelder Horsttoren Tel: 053 489 3884 Postbus 217 7500 AE Enschede

Internet Design Press Print

Peuscher Design Gildeprint Drukkerijen 750

04 05 08 11 12 16 20 22 24 28 30 34 37 38



Is our construction sector conservative, or are we? EXPLORING CIVIL ENGINEERING



Fehmarnbelttunnel KRAGTEN

De rotonde van morgen als redder van de bouwsector FROM THE BOARD

Building a bridge from board 2017 to board 2018 BACHELOR THESIS

Groundwater modelling



Data delivery - Alumni experience SPOTLIGHT

Beijing Daxing Airport



What we do and how it works SCIENTIFIC RESEARCH

Can we make our roads smarter WHAT’S NEW?

What happened in the civil engeneering sector recently? MASTER THESIS

Online model based urban traffic state estimation HAITSMA BETON


Joure interchange: logistical challange EDUCATIONAL UPDATE

News from the educational programmes WHAT IF....?

.... a extreme heatwave hits the Netherlands

Figures Frontpage: Highway intersection Werpsterhoeke near Leeuwarden | Photography: Sietse Kooistra From the editors: aerial view of Schelphoek, Zeeland | Photography: Rijkswaterstaat Column: Old Botlekbrug being removed | Photography: Rijkswaterstaat Committee David Barmentloo Joost Bult Floris Couwenber

CONCEPTUEEL Feb ‘18 Tom Evers Yorick Fredrix Lieke van Haastregt

Hidde Harmsen Rick van de Hoef Dianne Jacobs

Daan Kling Nils van der Wildt



The Netherlands: is our construction sector conservative, or are we? Why do we build the things around us? That’s a question we should always ask ourselves. Politics is a very important part of our constructed world. And the political choices we make as a country define the work we will do on a day to day basis. Professionals will sometimes have questions about their work. How come we still build non-sustainable projects? How come we have such a difficult time innovating as a sector? And why do we keep expanding our cities into countryside and nature, instead of more efficiently using less densely populated urban space. Many people will look at the nature of the construction sector, saying that it’s a

conservative one that is difficult to be changed. It is a sector in which the older generation is more slowly replaced by the new one. My opinion however is that the sectors’ conservatism is not the cause of the lack of innovation and eye for sustainability. It is the result of what we, Dutch voters, ask for our own country via the way we vote. The State is the sector’s biggest client. Therefore, the sector will perform what the ruling powers ask. If we vote for parties that happily keep us in our cars, we carry out projects that facilitate this. That does not mean it’s wrong, it is a political decision. Everybody should always be free to make their own political decisions in life. People should just be aware that political decisions do matter, and result directly into decisions about the physical world around us. So if you are wondering why the sector around us will not change, dare to wonder if they have any incentive by the parties in power to do so.



Author: Rick van de Hoef The Fehmarnbelttunnel is a tunnel which is planned to begin

construction was finished in 1951, therefore the connection

construction in 2020. It is supposed to be the longest immersed

with Gedser was again established.

tunnel in the world. Even the longest 2 tubes road tunnel in Europe (longer than the Gotthardtunnel in Switserland). This is


because it needs to cross the strait called Fehmarn Belt, and has

The line became busier and busier, bigger ferries needed to be

a length of 18,2 km. The belt lies between two islands, Fehmarn

made to cope with the extra vehicles. Therefore a new pas-

and Lolland.

senger car deck was added to the ferries. Also the companies Deutsche Bahn (DB) and Danske Statsbaner (DSB) had delive-


red such good connections that the ferry connection was not

Back in 1863, a ferry with room for a train is suggested to cross

temporary anymore. Therefore DB and DSB created a commit-

the Fehmarn Belt. The idea came because the conventional fer-

FIG. 1 Old poster of the ferry between Grossenbrode and Gedser

ries had a connection far more east, between Rostock (D) and Gedser (DK), also these ferries took longer, because they need to cross a bigger strait, the Great Belt. Not a lot happened until the Second World War started and Denmark was occupied by Germany. They made plans to create a railway bridge to cross the Belt. And not much later, in 1942 on Lolland they started to create the first highway of Denmark. But the construction of the highway was abandoned after only one year. After the war ended, Germany was split in two. West-Germany and the DDR. This came with a problem, the only ferry connections with Denmark were departing from the DDR. This resulted in the construction of the ferry terminal in Großenbrode in 1945. Großenbrode lies just below the island of Fehmarn. The



When designed the bridge had a length of 20 km and was meters high and a span of 724 meters.


supposed to be a cable-stayed bridge with 4 pillars of 280 The clearance of the bridge would have been 65 meters. The bridge was designed to have 4 highway lanes and 2 railway tracks.

It was designed by Dissing+Weitling, the same designers

as the Øresund Bridge and the Great Belt Bridge, two succesfull bridgeprojects in Denmark

tee to establish the feasibility of the project Vogelfluglinie (trans-

FIG. 3 Arieal overview of Rødbyhavn

port corridor between Hamburg and Copenhagen and there-

solution, but in 2010 the Danish project planners decided that an

fore Denmark), a shorter and faster route, between Puttgarden

immersed tunnel had less risks then a bridge, and would suffer

and Rødby. In 1955 they concluded that the ready was, but that

less downtime than a bridge. Also a bridge would push the limits

the financing on the German side was questionable. Despite this

of the technology available and next to that the costs of the tun-

problem, the Danish were eager to start with the line, they let

nel are the same as a bridge. With an expected intensity of 9500

the first ferry between Puttgarden and Rødby set sail in 1956, but

vehicles per day when opened, it is a smart move. It is expected

only for cars. A year later the financing issue was solved by the

that the intensity will rise to a staggering 15000 vehicles per day

German government, which led to the construction of a ferry

in the year 2047.

terminal in Puttgarden and Rødby. This was not the only link missing in the project, Puttgarden lies on the island of Fehmarn.

In December in the year 2011 Germany postponed the build of

To make the connection complete the Fehmarnsundbrücke was

the railway to Fehman until 2015. This was due to the economic

constructed. Both the terminal and the bridge were first used on

crisis and the German government had to cut in the new infra-

May the 14th in 1963.

structure projects, 25 per cent of all the projects were delayed.

Plans were made to create a fixed link between the two cities,

The Danish were eager to continue with the link, they applied by

but failed time after time. Only in 1991 when Denmark made an

the German government for approval for building according to

agreement with Sweden to create the Øresund Bridge, which

German laws. Another setback, the approval was denied in 2015,

sped up the investigations to create a fixed link, which happened

new legislation had just appeared and these were not expec-

between 1995 and 1999.

ted and were not fullfilled. In that same year the builders also applied in Denmark for the construction of the link according to


Danish law.This gave the Danish government the means to apply

In the year 2000 the Danish and the German governments star-

for a European grant for the projects construction. They applied

ted to push for a fixed link (at that point either a bridge or a

for 1,7 billion euro’s. This application was supported by Swed-

tunnel). In the following years, a bridge seemed the most violable

ish government, Germany’s government, the constituent state of

FIG. 2 The route of the “Vogelfluglinie”

FIG. 4 ICE-train driving aboard the ferry at Puttgarden


FIG. 5 Cross-section of the designed tunnel

Schieswig-Holstein and different companies from Sweden, Den-


mark and Germany. Also in 2015 the Fehmarmsundbrücke (the

The financing of the project is based on loans from the Danish

bridge that connects Fehmarn with Germany)was in such poor

government. This loan should be payed back to the government

state that the authorities decided that the maximum speed for

via the toll fees collected from the users of the tunnel. This

lorries should be lowerd to only 50 km/h. The bridge is not a

means that the citizens of Denmark do not have to pay for the

part of the plan to be replaced. In the beginning of the project,

construcion of the tunnel. The same financing method was used

the bridge was cleared and had passed tests, so it would con-

for the Great Belt Bridge and the Øresundbridge. By using this

tunue to exist when the tunnel was finished, but now it’s future

financing method, the costs will be much lower than when the

is unsure...

building company had to finance the project themselves.

In 2016 the Danish goverment approved the plans for construction. The companies also applied again to the German authori-


ties with the new legislations taken into account. The estimate

For the tunnel a trench has to be excavated on the bottom

of these applications are that they will be issued in 2018. Howe-

of the sea. The surface is at its deepest part 35 meters below

ver, the building companies expect that these approvals will be

waterlevel. The trench will have a depth of 16 meters and a with

appealed in court by the political objectors,. They estimate that

around 60 meters. The depth will bring a new challange, the

is will take two more years to finally start the construction part

trench will be dredged, but an conventional dredger only reaches

of the project.

a depth of 25 meters. The immersed tunnel will be devided into 89 sections with each


a length of 217 meters., and a weight around the 70000 tons.

Of course an other route was considered, the route Rostock

When the tunnel is immersed, the gaps will be filled up with

- Gedser, just like the ferries in the early days. This would have

rocks gravel and sand, to keep the tunnel in place. This interven-

been a logical choise because of the growing numbers of traffic

tion will only temporary affect the marine environment,, whe

from and to Poland and Central-Europe. The connection should

the tunnel is in place and coverd up, the seabed is restored to

be about 40 kilometers long. But because the interest of the

its former state. Of course some of the excavated soil will not

Scandinavian countries to have a connection to the West of

return to the original place, so this will be use to build new

Europe, the Fehmarnbelt link was chosen. This was not the only

coastal areas. These areas will mostly be constructed near Rød-

reason, the Fehmarnbelt link is half the distance, which makes it

byhavn and, to a lesser extent, near Puttgarden. This will hope-

much cheaper.

fully create more leisure in the area.

… has 4 tubes.


… the headroom in the tunnel is 5,2 meters … is 18,2 kilometers long

… exists out of 89 segments, each segment is 217 meters long and weighs around 70000 tons … has a maximum depth of 51 meters (floor of tunnel). … has a total cost of 5 billion euros.

Stay updated on the project on:




… has 4 highway lanes and 2 railway tracks.


… is immersed


waarin de maatschappelijke opgaven juist om continue vernieu-

een middelgroot adviesbureau uit Lim-

wing vragen.”

burg/Brabant, met een ogenschijnlijke

Zo openen wij, “bouwers van Nederland”, ons betoog inzake het

hoofdrol voor een betonnen rotonde in

‘Waarom?’ van de Marktvisie. Maar tegelijkertijd beschrijven wij,

het mooie Maasdorp Steyl in de gemeente

“bouwers van Nederland”, ook het scenario, wat de oorzaak is


geweest voor de verkokering binnen de Bouwsector: gebrek aan

Kragten maakt van deze gelegenheid

visie, gebrek aan flexibiliteit en, wellicht als maatgevende basis

gebruik om haar bedrijfsfilosofie te delen

voor alles, onvoldoende durf om te investeren in innovatie. Hoe

met de Bouwsector (van morgen). Waarbij een ogenschijnlijk

is het überhaupt mogelijk dat wij het als sector zo ver hebben

klein, eenvoudig project laat zien waarom en hoe de Bouwsec-

laten komen?

tor zou moeten evolueren om klaar te zijn voor deze toekomst.

Gelukkig is er nog hoop voor de dag van morgen….

Wij nemen u graag mee in onze filosofie, de meerwaarde en de resultaten daarvan.

DE ROTONDE VAN MORGEN De basis voor ‘De Rotonde van Morgen’ is bijna twee jaar gele-


den gelegd binnen het Platform Ketensamenwerking Zuid van de

“De afgelopen jaren heeft de markt van bouw- en infraprojec-

provincie Limburg.

ten te maken gehad met grote veranderingen. De terugloop in

Als ‘believers’ in de meerwaarde van ketensamenwerking von-

investeringen in de sector leidt ertoe dat marktpartijen forse

den vertegenwoordigers van de gemeente Venlo, Kragten en

concurrentie ondervinden en aanpassingen in de organisatie en

Den Ouden Groep elkaar in dit Platform. Met vertrouwen in

projectbenadering hebben doorgevoerd. Niet alleen staat hier-

elkaar als uitgangspunt maakten we gebruik van ieders aangebo-

door de relatie tussen opdrachtgever en opdrachtnemer onder

den expertise.

druk bij de uitvoering van projecten. Het leidt er ook toe dat de

Gezamenlijk werd het concept voor ‘De Rotonde van Morgen’

ruimte klein is om in innovatie te investeren. En dat in een tijd

mogelijk gemaakt: de eerste Cradle-to-cradle-rotonde, gereali-


seerd op basis van ketensamenwerking, ter wereld!

zijn op de coördinatie van verschillende schakels in de keten,

Het doel van dit concept is om op een betere, snellere, goedko-

met als doel de gehele keten te optimaliseren als ware het één

pere en vooral duurzamere manier deze rotonde te realiseren:

eenheid (één gezamenlijke organisatie). Dit in tegenstelling tot

Integraal Ketenbeheer door Ketensamenwerking oftewel Samen

de situatie waarbij iedere speler in de keten zich richt op het

garant voor de oneindigheid van materialen en constructies!

optimaliseren van zijn eigen individuele (schakel)prestatie.”

Maar ‘De Rotonde van Morgen’ was niet alleen de wijze van

Wij durven te constateren dat deze theorie voor de GWW-sec-

samenwerken van morgen, maar ook de technologie van morgen.

tor onvoldoende is. Met name het feit dat zowel projectcontext

Passend bij de ambities van de Venlo Principes geven de part-

als ook het daarmee samenhangende risicoprofiel per project

ners maximale invulling aan de Cradle-to-cradle-filosofie. Het

wijzigt als ook dat de prestatie van de keten (per project) vooral

vertrouwen in elkaar zorgde ervoor dat materiaaltechnische en/

buiten de (directe omgeving van de) keten te “meten” is, maakt

of constructieve innovaties open en eerlijk met elkaar gedeeld

dat ketensamenwerking in de infrastructuur wellicht vraagt om

werden en resulteerde in een uniek project en projectresultaat.

een aanvulling die kenmerkend is voor deze sector:

Maar hoe kan ketensamenwerking voor een simpele rotonde

“Ketensamenwerking is een niet-vraaggestuurde, projectonge-

in de gemeente Venlo nu de redding voor de Bouwsector zijn?

bonden samenwerking tussen partners uit de keten, die zich per project richt op het managen van activiteiten, die gericht zijn op


de coördinatie van verschillende schakels in de keten, met als

Zoals aangegeven is de basis voor de Rotonde gelegd binnen het

doel de gehele keten voor dat project te optimaliseren als ware

Platform Ketensamenwerking Zuid. Dit Platform is een initiatief

het één eenheid.”

van onder andere de Provincie Limburg, Bouwend Nederland en

Waarom is samenwerking binnen de bouwketen voor de Bouw-

Uneto VNI. Sinds 2013 hebben zich, binnen het Platform Keten-

sector van belang?

samenwerking Zuid, opdrachtgevers, opdrachtnemers, adviseurs

De deelnemers van het Platform waren en zijn het met elkaar

en toeleveranciers uit de Bouwsector samengepakt om middels

eens dat de manier waarop we in het verleden, maar ook nog

deze versnellingstafels en praktijktafels een impuls te geven aan

op dit moment, met elkaar samenwerken geen duurzame basis

de introductie van Ketensamenwerking in de Bouwsector.

vormt voor de toekomst.

Het Platform wordt gesteund door De Bouwagenda, zoals die

Maar waarom doen we het dan niet?

op 29 november 2016 per brief, door het Ministerie van Eco-

Ondanks dat ook buiten dit Platform veel spelers in de bouw-

nomische Zaken aan de Tweede Kamer is gepresenteerd. In de

sector het belang van ketensamenwerking onderschrijven,

Bouwagenda zijn een drietal ambities geformuleerd.

ervaart men dat het scheppen van de voorwaarden om te gaan

“Om deze ambities te realiseren zijn forse investeringen nodig

samenwerken buiten de invloedsfeer van de individuele spelers

in een betere samenwerking binnen de bouwketen, het op gang

ligt. Moet er gewacht worden totdat de ‘ketenpartner’ vooraan

krijgen van wezenlijke innovaties, investeren in menselijk kapitaal

in de keten start met ketensamenwerking of is iedere ketenpart-

en vernieuwing van instituties. Een aanpak op al deze fronten is

ner in staat om binnen zijn invloedsfeer ketensamenwerking te

nodig om de sector op een structureel hoger plan te brengen en


van internationale allure te laten zijn.”

Opmerkelijk voor de Infra-sector is dat deze sector al jaren-

“Een betere samenwerking binnen de bouwketen”, wat is dat

lang ervaring heeft met tools die een essentiële bijdrage kunnen


leveren aan een het komen tot en/of geven van invulling aan

Steeds vaker wordt voor de beantwoording van deze vraag


de definitie van prof. dr. Jack van der Veen als uitgangspunt gehanteerd:

• Denk




Best Value


“Ketensamenwerking is het managen van activiteiten die gericht

• Denk aan RISMAN;

FIG. 1 Project ‘droom’ als redder van bouwsector

• Denk aan het LEAN-principe; • Denk aan Systems Engineering; • Denk aan BIM (het Bouw Informatie Management). Helaas constateren we dat al deze tools – veelal afzonderlijk – toegepast worden en niet of nauwelijks in samenhang. Deze samenhang kan en zal alleen ontstaan in een samenwerking. Maar voor het verkrijgen van samenwerking hoort een ander gedrag. Een gedrag op openheid en eerlijkheid en gebaseerd op wederzijds vertrouwen.




soonlijke ontwikkeling wellicht het allergrootste.Vanaf de eerste

In deze baanbrekende pilot hebben we vanuit onze hernieuwde

kennismaking en oriënterende gesprekken hebben de mensen

definitie voor Ketensamenwerking in de infrastructuur, op basis

achter de partners in volledig vertrouwen en in alle openheid en

van vertrouwen, en middels een partnerselectie de ketensamen-

eerlijkheid ideeën, kansen en risico’s gedeeld. De uitvoerder van

werking definitief en formeel gevormd. Gezamenlijk met alle

de uitvoerende partner heeft naast de ontwerper van de advi-

ketenpartners, inclusief de diverse leveranciers en adviseurs van

serende partner gezeten om een optimaal uitvoeringsontwerp

elke partner, hebben we een project start-up doorlopen, waarin

te maken. De kostenraming is met de projectverantwoordelijke

ons doel SMART aan een ieder verduidelijkt is: het ontwerpen

van de opdrachtgever en de vertegenwoordigers van de overige

en realiseren van een infrastructureel project, waarbij maximale

ketenpartners gemaakt. Winst en risicopercentage zijn samen

invulling is gegeven aan de Cradle-to-cradle-filosofie. Op basis

onderbouwd en vastgesteld.

van de RISMAN-methodiek is het risicomanagementproces

En het project was niet duurder, het was zeker sneller, het was op

vormgegeven en hebben we de risico’s en de daarmee samen-

het gebied van C2C het allerbeste en het was voor elke mede-

hangende risicopot gekwantificeerd. Uitgaande van die risicopot

werker leuker!!! En dat alles vanuit de Kragt van Vertrouwen.

hebben we ons dynamisch verdienmodel vormgegeven, ervan uitgaande dat de beheersing van de (h)erkende risico’s zou lei-


den tot reductie van faalkosten en aldus tot vergroting van onze

Kragten is een onafhankelijk adviesbureau voor de openbare

gezamenlijke winst.

ruimte zonder belangen bij marktpartijen. Onze positie als advi-

Met alle ketenpartners is ook de invulling gegeven aan de

seur wordt daardoor versterkt. Het stelt ons bovendien in staat

LEANx-sessies: planning, maar vooral ook inzet van mens en

om te allen tijde onze kennis en ervaring te verrijken, werkende

materieel en transportbewegingen zijn geoptimaliseerd.Vanaf de

vanuit verschillende invalshoeken en met verschillende partners.

project start-up is, gebruikmakend van de denk- en werkwijze

Kragten heeft een netwerkorganisatie(!), die wordt gefaciliteerd

van Systems Engineering, gewerkt aan een Bouw Informatie

door de directie. De directeuren zijn een belangrijk deel van hun

Management-model, waarin we de circulariteit van de construc-

tijd uitvoerend bezig in projecten. Soms als consultant, dan weer

tie en de daarin gebruikte materialen hebben vastgelegd. Dit

als inhoudsdeskundige. Dat is een bewuste keuze. Zo staan zij

betekent dat nu, bij oplevering van de rotonde, de gemeente een

dichtbij de klant en weten ze wat er zich in de markt afspeelt en

digitale grondstoffendatabank heeft ontvangen, incluis een sloo-

kunnen zij beslissingen nemen op basis van waargenomen feiten.

pinstructie om de toegepaste, niet-toxicologische en 100% upcy-

Redenerende vanuit die klanten zijn wij in onze aanpak gericht

clebare grondstoffen te traceren en te hergebruiken. Daarbij is

op samenwerking. Zowel met opdrachtgevers voor de invul-

per grondstof de economische en/of functionele restwaarde

ling van de klantbehoefte, als met partners voor de gewenste

als materiaal of als constructiedeel gedurende de levensduur

verbreding van onze dienstverlening en op samenwerking in de

beschreven, waarmee De Rotonde van Morgen ook vooral voor

keten waar het geheel meer is dan de som der delen. Zo is

morgen is geworden en zal blijven.

de Rotonde van Morgen ontstaan en zo ontstaan dagdagelijks

Wat we niet willen vergeten is tenslotte het derde abstractieni-

onze nieuwe “Rotondes van Morgen”. Dromen die werkelijkheid

veau waarop we de verspilling zijn tegengegaan: de mensen in de

kunnen worden door vanuit Vertrouwen en in alle openheid en

samenwerking. Ondanks dat dit raar klinkt, is de winst in de per-

eerlijkheid samen te werken.

FIG. 2 Render van de rotonde van morgen in Steyl



Author: Ivo Bruijl

Exams: check. Projects: check. Presentations: check. General

Most second-year students will remember Saskia as part of

Meeting: check. The past weeks have been quite busy for us as

the Kick-In Campcommittee of 2016, others might know her

a new board. The Erasmus Bridge (or Rome, whatever you like)

from lunch lectures which she organised while being part of the

was not built in a day and similarly it takes some time to get used

InterExice. When you have got questions or complaints about

to the new situation of being a board member. After almost two

the education, she is the person to go to, since she is the officer

months of writing a policy plan and preparing for our board year,

of educational affairs.

it all really kicked off after the General Meeting on 18 January.

My own name is Ivo, and you might also know me from the

The first two weeks were extremely busy, because we still had

Kick-In Camp of 2016. Besides, I canoed at the BetonKanu-

to finish our modules. However, the hectic times are over now

Regatta in Cologne last year as member of the BetonBrouwers.

and we all can fully focus on our board responsibilities.

In 2018, I will be the chairman of ConcepT, which means I will

Let me explain who we are. Thijs is most well-known for his

try to keep the association together and keep an eye on the

chairmanship of the BuLa-committee last year, which resulted


in an epic trip to the Polish city of Wrocław. In the coming year,

Now that the first month of our board year is over, we already

Thijs is the secretary and officer of internal affairs of Con-

experienced some great activities. The Symposium committee

cepT, which means that he will manage most of the media,

organised a really interesting day of lectures and workshops

keep the administration up-to-date and be the board mem-

around the theme ‘Bridging the Gaps’ on 14 February. The day

ber who focusses on getting and keeping members active.

after the symposium we all suited up and put on a mask to join

Wouter led the Almanaccommittee 2017 to a wonderful

the yearly Gala. Currently, we are looking forward to the BuLa in

almanac which was presented on the Winter Weizen Wonder-

Plzeň, the outcome of our newly created Projectcommittee and

land & Absolutely Amazing Almanac Drink shortly before the

all the other activities that will take place in the coming year. We

Christmas break. Within the board, Wouter will make sure that

know that all committees will show that where there is a will,

ConcepT will not go bankrupt, since he is the treasurer.

you can build a bridge.

Besides organising the BuLa last year and designing the almanac of 2017, Niels helped ConcepT to prepare for the internationa-

Ivo Bruijl

lisation by contributing to the Internationalisation Guideline. I


bet he will be on the phone with companies most of the time in

30th Board of ConcepT

the coming year since he is the officer of external affairs in 2018.

‘Ubi Voluntas, Pontem Facimus’




it rains very hard. The ground will become saturated and can

ter will be always under you in the

not absorb more water. It will take a long time till the paddles

ground. And it is very important to


have groundwater. When you walk you see trees that only can grow


when groundwater is present. When

In Enschede, the groundwater level is very high. This is mainly

it’s raining, you have to watch out for

caused by the closed ditches years ago. In houses this high water

puddles. This water in the puddle will

level can be noticed because crawl spaces under the house are

end up in the ground. But sometimes,

full with water and walls easily become mouldy. Especially during

FIG. 1 The formed cone of depression due to the lower groundwater level during extraction (Adini, 2011)


FIG. 2 Visualised soil layers of a iModFlow model in iMOD (Deltares, Why iMOD: the iMOD approach).

heavy raining, people will notice it. A simple way to measure the

water. In this situation, the ground water level will become lower

groundwater is to dig a hole, wait for a moment and the hole will

than in the original situation before extracting.

be filled with water till the groundwater level.

The amount the groundwater level will lower during extracting

On the other hand, a low groundwater level has also a lot of

depends on several factors: the volume of water that will be

impact. Vegetation is not able to survive and the soil becomes

extracted, the soil layers and the transmissivity (=permeability)

very poor. This can be an economical and social problem for a

of the soil layers.The lowering of the groundwater level has a bit


of a funnel shape if the layers have everywhere the same trans-

For every type land usage, another groundwater level is desired.

missivity. This is called a cone of depression. The more water

So even in The Netherlands, it is possible the ground water level

will be pumped, the lower the groundwater level will be and

is too low. Think about extracting ground water for drinking

the further away of the pump station the lowering will happen.

FIG. 3 The yellow area shows the dataset Azure, the blue area shows the dataset Hydromedah and the green area shows the overlap of the models Azure and Hydromedah.

FIG. 4 The available Dutch groundwater datasets of the iModFlow model (Minnema, 2016)



However, due to irregular composition of soil layers with all their

soil layers can be defined and a lot of characteristics such as

own transmissivity, the funnel shape can not perfectly be applied.

transmissivity and vertical position must or could be inserted

Groundwater streams very slow. The exact speed depends on

to each layer. Also the position of groundwater pumps can be

the transmissivity of the soil type. Groundwater can cover 50

inserted in the model.

meters per day in gravelly coarse sand, but in clay it is possible

iModFlow is an extension of ModFlow. For The Netherlands,

that it only covers 1 meter per year (Smedema and Rycroft,

several iModFlow datasets are available. Each dataset covers a

1983). During groundwater extraction, the water will take the

part of The Netherlands and sometimes there is overlap. For

way of the less resistance. With everywhere the same transmis-

the province of Utrecht, two datasets are available: Azure and

sivity, the groundwater level will get a funnel shape. But with a

Hydromedah. First of all, it seems not to be a problem to have

lot of different layers and transmissivities, the shape can get all

two datasets, but the problem is that the results of both datasets

kind of shapes.

are different due to different characteristics within the dataset.

GROUNDWATER MODEL MODFLOW A groundwater model can be used to predict groundwater


levels for a certain quantity of groundwater extracting.

During my bachelor thesis, I have researched which dataset

There are different types of groundwater models. One of them

(Azure or Hydromedah) can used the best for the Province

is ModFlow. This is a three dimensional model that calculates

Utrecht. Specifically, in the thesis some characteristics and

with the finite differential method. The model exists of many

results of the models are compared with reality for four locati-

cells. Each cell has its own properties and get values as input

ons with groundwater extractions to conclude which model is

from one neighbour cell, calculate some new values and give

the most realistic. The characteristics that are looked at, are the

these new values to another cell. In ModFlow, the amount of

transmissivity, the resistance, the rivers and the wells. Resistance

FIG. 5 Ground water level of Leidche Rijn with and without groundwater distraction.


FIG. 6 The quantity of water exchange between the groundwater and the surface water for the datasets Azure and Hydromedah. Water could be infiltrate from the surface into the ground or it can be conducted from the ground into the surface water.

is the characteristic used for layers in which water flows rela-

change much could be the transmissivity or resistance of the

tively slow such as clay. Transmissivity is used for the layers in

layers or the infiltration possibilities of rivers. For this characte-

which water flows relatively fast such as sand.The wells describe

ristics, all layers above the layer on which the extraction takes

all the ground water extractions.

place are compared.The exchange of water between the surface

The difficulty of groundwater models are that you don’t know

waters and the groundwater are quite the same for Azure and

all actual values of the characteristics. The transmissivity of the

Hydromedah at Leidsche Rijn So this will not cause the different

type of soil can be measured. But the types of soil, that will be

results of the water levels. For Leidsche Rijn, the transmissivity

determined with taking soil samples, can’t be determined for the

variates not as much (respectively 1,5 times higher and lower for

whole area. It is possible, that within hundred meters, the types

Azure and Hydromedah compared to REGIS). But, the resistance

of soil are very different. Especially the types of soil in the area

variates a lot. For the Azure model, water flows three times lon-

of the Utrechtse Heuvelrug in the Province of Utrecht variates

ger through the clay layer than the REGIS model shows. And

much. So there must be made an assumption of the soil types

for Hydromedah, the water flows even slower: almost fifteen

that can be found in an area based upon the measurements.

times slower than REGIS. But this does not say the Azure or

REGIS II is a kind of dataset that made assumptions of these soil

Hydromedah dataset are incorrect. Only the chance that the

characteristics based on measurements. But, using exactly these

resistance of Hydromedah is correct, is quite small, because of

soil characteristics, the ModFlow model will calculate water

the extreme high value.

levels that are not identical with the measured water levels. So

All in all, it is difficult to say which model fits the best. For Leid-

the characteristics of REGIS II must be calibrated to get more

sche Rijn, it is likely that Azure will fit the reality the best. But

realistic water levels. This is the reason the datasets Azure and

for the other three locations in the Province of Utrecht, it dif-

Hydromedah are different: they are both calibrated differently.

fers per location which dataset seems to be the best. But there

In the first comparison groundwater levels of Azure and Hydro-

needs to be further research like looking to more locations and

medah were compared with measurements. In this comparison,

maybe more layers to know it with more certainty which model

it is important to know that each soil layer can have another

fits the reality the best.

because this layer has the most visible influences. In Figure 6, the differences in water level are visualized for the city Leidsche Rijn. In this city, they started with pumping in around the year 2000. Without water extraction, the ground water levels of Azure, Hydromedah and the interpolated measurements are not identical.This also holds with groundwater extraction. But, there can be seen that the water level of the models are not influenced much by the extraction, but in reality, the groundwater level clearly decreases. Reasons that the groundwater level of the model does not

Adini, A., (2011). Zone of Influence. Retrieved from www. at 2018-02-03. Deltares. Why iMOD: the iMOD approach. Retrieved from at 2018-02-04


groundwater level. In this research the top layer is compared

Minnema, B. (2016). What triggered the development of imod [powerpoint]. Retrieved from www.slideshare. net at 2017-04-03.

Smedema L.K. & Rycroft D.W. (1983). Land Drainage:

Planning and Design of Agricultural Drainage Systems. Cornell University Press, Ithaca, NY, p. 376




A SOUTH AFRICAN EXAMPLE Author: Niels Vossebeld

Civil engineers can work anywhere. From managing a construc-


tion project in Indonesia to thinking of creative solutions to

Following the significant attraction of the city, insufficient affor-

solve water management problems in the United States of Ame-

dable housing is being built in Durban (South Africa) and the

rica. This article touches on the professional experiences of a

number of informal settlements and population living in informal

Twente alumnus in Durban, South Africa.

areas is ever-increasing. Figure 1 gives an impression of the rapid

After providing a brief background, the article shares practical

expansion of just one of the many settlement areas.

experiences of working on a compelling large infrastructure

Informal areas lack (a part of) those services we all assume as

delivery programme: The Provision of Water and Sanitation

normal in the Netherlands. Think of electricity, water, or sanita-

Services to Informal Settlements and Schools in the eThekwini

tion. The Water & Sanitation project of the municipality aims to

Municipality. On this programme I was involved from the start

deliver rapid measures to address the most urgent needs caused

to set up data management solutions in general and – later – to

by the general formal housing backlog. The programme reflects

tackle one specific aspect identified as high risk to successful

a growing acknowledgement that the conventional upgrading of

programme execution: delivery of asbuilt data.

informal settlements is inherently slow and costly. Conventional

FIG. 1 Rapid growth of informal settlement areas from 2008 to 2015


upgrading would go via housing delivery, permanent engineering

the design is to accommodate for the future: taking into account

services and housing along with formal approval and establish-

more formalized development of the settlements (i.e. individual

ment processes. Therefore, the delivery of the programme is

household connections). Hence, the location of the facility and

focused on rapid delivery of temporary facilities at scale. Alto-

particularly the associated infrastructure network and bulk ser-

gether, with the higher aim to improve the immediate challenge

vices are designed in such a way so as to avoid fruitless expen-

of water borne disease and poor health conditions evident in

diture when future formal developments take place. Further, the

informal settlements.

DC’s are responsible for site supervision and quality control

My former employer, SMEC South Africa, is providing the profes-

during the construction phase. Facilities can be in mixed or male

sional services associated with the role of Programme Manager

& female form and are called “ablutions”. They consist of sho-

(PM) and overall programme governance. The programme is in

wers, toilets, wash-hand basins and outdoor wash-troughs with

its third phase which runs over a period of approximately three

urinals and a storage cubicle included in the male ablution. See

years.The main PM team consists of project managers, cost con-

photos 2.1 to 2.5 for examples.

sultants, and site staff. This team is supported by our in-house

Let’s throw in some numbers to illustrate the scale and impact

team of software developers & GIS professionals. Communities

of the programme. To date phase 3 has delivered over 200 ope-

are identified by our team in cooperation with the Human Set-

rational facilities, with a further 140 currently under construc-

tlements Department of the municipality who then is involved

tion and another 200 in the planning pipeline. As ablutions are

in prioritization of locations. Amongst others, community and

provided per 50-75 dwellings (approx.) and within a 200m wal-

municipal department concerns and feedback are managed

king radius. This has already provided over 15 000 households

through the PM’s stakeholder management processes to ensure

with access to basic sanitation and, hence, improved the both

adequate project communication is achieved. Furthermore, the

the circumstances and environment of these communities. Each

PM allocates work packages, consisting of certain informal set-

facility can be considered as a stand-alone project. Also, the pro-

tlements, to the Design Consultants (DC).

gramme consists of more than 70 companies.

DC’s consider the required size and location of new water and

One aspect of the programme is very specific for the South Afri-

sanitation infrastructure in relation to any existing services.

can context: a substantial amount of these companies are small

Though the facilities themselves are intended to be temporary,

and contracted into the programme to achieve development



the CAD data into the clients geodatabase. Though from a conceptual point of view very similar to information delivery using BIM principles, we had some specifics of the programme to take into account: • Capabilities of the parties involved. The (emerging) DC’s responsible for delivery of asbuilt information were contracted to be CAD capable (or still as emerging to be). Hence, we were limited in the format of delivery. Also, our solution design focused on keeping it simple (which by the way is also good practice in NL). • Lower level of early involvement. Due to their backlog and FIG. 3 Example of South-African site work

ongoing workload, the availability of the client was rela-

goals (>20% of contract value). Phase 3 for example includes

tively low in the earlier phases of the project. Especially,

32 developing contractors and 8 developing Design Consultants.

when compared to the Netherlands’ planning culture (in

Meaning, these companies are intended to grow into sustainable

Dutch: ‘polderen’). Making it key to develop our specifi-

enterprises by participating in the design and/or construction of

cation stand-alone using the clients Geodatabase schema

the programme under mentorship of more experienced parties.

and using inputs from experienced GIS experts and project

Thus, contributing positively to both eThekwini and South Afri-


can radical and local economic transformation efforts.


Our team organized a pilot phase to allow for asbuilt workshops

Phase 3 of the programme started just a few weeks after I

to support feedback and learning. Some of the DC’s made good

arrived at SMEC South Africa. I was involved from the start to

use of this opportunity. These parties asked good questions and

help set up a master data management solution for our pro-

gave us input to improve our specification. Others took longer

gramme management team and was in charge to tackle deli-

to improve their quality control and deliver asbuilt data up to

very of asbuilt data at a later stage. Successful delivery of asbuilt

contractual standards.They clearly were not used to work along

data was considered one of the key technical challenges on the

a formal data delivery specification. To support all DC’s involved

programme, given the variety and maturity of (emerging) DC’s

we shared PowerPoint slides with bullet points and snapshots of

involved. The process showed to be laborious and problematic

‘known issues’ ranging from uncompleted fields, unreferenced

during the previous phases.

photos, and misplaced or unsnapped lines in their CAD dra-

What is asbuilt delivery? After completion and practical hand

wings. These known issues were to allow them to incorporate

over of each ablution facility the client is to be provided with

checks in their quality system. Personally, it was a good pro-

an accurate record of the new infrastructure. With the many

fessional experience to directly interact with the DC’s and try

parties involved it was a crucial aspect for the PM to standar-

to keep a good working relationship, while enforce a contract

dize delivery and ensure data quality assurance measures are put

for data delivery that was more rigid than they were used to.

in place. The volume of asbuilts would be relatively high. Assu-

Where possible we could improve the flexibility of our tooling

ming 540 facilities, over 1080 asbuilt CAD drawings were to be

to automatically correct ‘common input issues’. As this at times

expected (for each site one for sewer and one for water) and

supported our end-goal to obtain a high-quality assured delivery

over 2700 georeferenced photos. All of this data has to end up in

to the client.

the clients geodatabase in sufficient detail and a consistent form.

FIG. 4 Example of South-African site work

SOLUTION DESIGN Our data delivery solution included two main technical parts. Firstly, a standardized asbuilt data delivery specification was written to formalize contractual requirements for delivery of asbuilts from the point of view of both process and data content (structure, naming, topology, format). Secondly, we developed and implemented tools to (1) automate verification of CAD data and photographs against this specification; and (2) load of


Project impact

kily, something like a shared business culture does exist in the

Altogether, setting up the programme-wide standard and related

office. In our office of 200 staff everyone spoke English. Or was

tooling for asbuilt data delivery has showed to be an efficient

intended to. I must admit, my one Dutch colleague and I were

manner to assure quality, while avoiding laborious manual verifi-

one of the examples showing occasional misconduct: one simply

cation of large batches of complex data.

connects the easiest using your own tongue. One of the many other differences when comparing South Africa


to the Netherlands is the difference in approach to hierarchy.

Though my background gave me a solid theoretical foundation

This shows as – amongst others – senior staff / leaders in South

to do my job, when I started I still had many practical lessons to

Africa at times are looked at and expected to have a plan inclu-

learn. In general, working abroad was a broadening experience

ding specific directions before allocating to, or discussing work

that helped to widen my horizon. One particular aspect that

with subordinates. At times this felt strange for me – it seemed

takes time to learn and understand is local business culture.

like the person in charge felt like they had to know it all about

Back in the Netherlands I feel our country is quite homogene-

a complex and specific problem. This aspect is very different in

ous compared to South Africa: a country with 11 official lan-

our Dutch egalitarian culture. In general, our leaders take a more

guages and at least even many different cultures. In the greater

facilitative approach. Also, quite quickly I noticed to really have

Durban area one mostly finds people of English, Zulu, and Indian

a different attitude to authority compared to my peers in South

background and a minority of Xhosa and Afrikaans people. Luc-

Africa. Though sharing ideas is also appreciated in South Africa,

Living and working in South Africa is exciting and challenging at the same time. For good reasons, the country has the highest repeat tourism of any long-haul destination in the world. Travelers are raving about the beauty of its wildlife, ocean beaches, and pristine nature areas like the Drakensberg mountains. All of this was within an hour drive of where I used to live.Though, despite these beautiful tourism prospects, the country also faces the problems of a developing country: education, unemployment, and inequality. Effects hereof are visible in daily life. Niels studied Construction Management & Engineering (CME) and, thereafter, completed a PDEng in civil engineering at the University of Twente focused on BIM. After graduation in 2015 he moved to Durban, South Africa (eThekwini municipality): “I was up to something different at the time and that’s what I got”. At first it wasn’t easy to get started abroad: obtaining a work permit took over 5

depending on the leaders involved, one should be a bit more aware as to when and how to pitch in ones two-cents-worth, taking into account the level of professional seniority of others. An example of a difference one only learns to understand over time. So, civil engineers can do their work anywhere.Yes, though working in a different culture will really help you to learn something additional.

INTERESTED? Don’t hesitate to contact me via LinkedIn. I am always interested to chat about the practicalities related to working in South Africa. Also, when interested to know more about data delivery solutions (or BIM / Data Management). At my new employer Tauw bv we have various opportunities to do an internship or thesis on these topics. FIG. 6 Example of an ablution facility

months. Though it took only several weeks to get a job after arriving in the country. My role at SMEC South Africa was that of a Systems Analyst, which includes analyzing, designing and implementing information systems or data solutions. Analysts assess the suitability of information systems in terms of their intended business outcomes engineers and project managers).


and liaise with managers, programmers, and end users like Now I am back in the Netherlands and like to share some of my professional experiences via a story regarding a compelling programme I worked on. Besides describing

what I think is an interesting case story, I hope this piece will inspire some students to broaden their horizon and choose to work in a developing country for a while.




The Beijing Daxing is being built to be the largest airport in the world.The airport is estimated to handle 75 million passengers in 2025. The construction was started at December 26th of 2014 and is scheduled to finished in September 2019. The construction costs are estimated 11,2 billion dollars. The airport is the second airport in Beijing, and is supposed to be the hub for the Skyteam airlines and some of the regional airlines. The Airport will also have a military part.

THE EDUCATIONAL COMMITTEE WHAT WE DO AND HOW IT WORKS Author: Educational Committee ConcepT Since a few months, ConcepT has a new committee:The Educati-


onal Committee. A lot of study associations have an Educational

The Educational Committee works like a sounding board for

Committee. The purpose and the structure of the educational

the Officer of Educational Affairs. Most of the students know

committees differ a lot. However, the aim of the committees is

whom to address in case they have an educational complaint.

the same: get a better insight in education. As Officer of Edu-

The problem is that students often do not tell their complaints

cational Affairs, the main task is to know what is going on with

because they think it is not important. For example, too small

respect to education. The set-up of an educational committee

lecture rooms, so some students could not sit on a chair during

may help the Officer of Educational Affairs to be well informed

a lecture. The Educational Committee should make it easier for

of all (new) educational affairs.

students to address small complaints or suggestions. The Educational Committee has meetings each first Mon-





Monday 5-2 Monday 5-3 Monday 9-4 Monday 7-5 Monday 4-6

12:30 12:30 12:30 12:30 12:30

Z104 Z104 Z104 Z104 Z104

Olof Baltus Hello my name is Olof Baltus, second year bachelor student Civil Engineering. I became a member in the educational commission because I am a very critical person and not afraid to criticise the education at the university. I am also member

day of the month. Before the meeting, the committee mem-

at the student association ‘Taste”.

bers ask their fellow students if there are any complaints. During the meetings, there is a structured discussion about

Bjorn Schutte

complaints within the module, within the study programme,

My name is Bjorn Schutte, I’m a second

study facilities and internationalisation. The meetings are

year bachelor student. I became a mem-

open for all members. So, do you have any complaint you

ber of the Educational Committee

want to address to the committee or do you want to contri-

because I like the idea of the commit-

bute to a discussion? Come visit a meeting of the Educatio-

tee as a link between students and tea-

nal Committees. In the table, you can find our meeting days.

chers. I hear complaints around me very often and I think that indeed educational


improvements can be made sometimes. I

Currently, the Educational Committee has 7 members:

hope that my fellow students come to me and that the commit-

4 bachelor students, 2 master students and the Officer of Edu-

tee achieves its goal.

cational Affaires of ConcepT. Maria Elmeidaa Ole Neijenhuis

My name is Maria Elmeidaa. I am a Hi everyone! My name is Ole and cur-

24-year-old civil engineer from Homs,

rently I am doing the first year of the Civil

Syria. I am continuing my higher educa-

Engineering programme. I have really

tion studies at the University of Twente

enjoyed the modules thus far and I hope

in the program of Construction Manage-

this joy will apply to all future modules

ment and Engineering. I live at the city

within the bachelor programme as well.

center of Enschede in the ITC international hotel. I have not

I have chosen to join the Educational

lived in the Netherlands before; therefore, I am still adjusting to

Committee to represent the interests of

the weather here. However, since I am an international student,

CE students, because I think it is impor-

I like how international this country is.

tant to all have qualitative education.Together we will constantly try to improve the quality of education, facilities, Internationali-

Sam Westerhof

sation etc. Our main goal is to maintain our achievements and

My name is Sam Westerhof, born and

try to make the coming years even better than now.

raised in Enschede 21 years ago. I’m a first year CEM-master student, following

Roussi Roussev

the water management track. Next to

Hello my name is Roussi! I’m coming

my study, I work in a store in Enschede,

from Bulgaria and I’m joining the educa-

like to play some tennis and spend time

tional committee. By taking part in this

with friends. I recently joined this new

committee my goal is to help the Inter-

committee to help contributing to better education for all of us

nationalization and find solutions for

and to help solving the smaller daily life educational issues we

educational problems that students may

all come across sometimes. So, everyone who has questions or

experience in their study. I also hope to

is unsatisfied about courses, teachers, educational facilities or

improve the explanations for processes

other things related to the education, feel free to tell and we will

and conditions of this study for first year students

discuss it within the committee.





Daan Brinkerink, Sjon van Dijk and Denis


Makarov recently worked in an ASPARi

The Asphalt Paving Research and innovation unit (ASPARi) is

team installing Fibre Optic sensors and

currently encouraging innovation in the asphalt pavement indus-

Radio Frequency Identification (RFID)

try, especially focusing on professionalizing important process

chips in an asphalt layer on the UT cam-

parameters during construction. Asphalt paving and the design

pus. A portion of the Boerderijweg was

of asphalt mixtures have not changed much for over 50 years.

being reconstructed and ASPARi was given permission to install

However, the consequence of this stagnation can at the least be

sensors into the new asphalt layers as part of the university’s

called drastic, with work processes considered to be outdated

Living Smart Campus project. Asphalt temperature was to be

leading to variability and possible premature failure in the con-

monitored using Fibre Bragg Grating sensors, RFID chips and

structed asphalt layers.


Traditionally, asphalt construction uses several machines in the

FIG. 1 Old and new asphalt roller


process: Trucks transport asphalt to the construction site and

to failure where the holes have been drilled. Perhaps the biggest

dump it into the asphalt paver. The paver paves the hot asphalt

challenge is that the density can only be measured after the mat

mix onto the roadbed in an even and smooth layer. The rol-

has cooled down completely. In short, nothing can be changed if

lers compact it using their own weight and occasionally with

something is wrong with the asphalt layer.

vibration. Asphalt paving for years was considered a job for real

Research conducted by ASPARi shows that an asphalt mat

craftsmen who could “feel” when the asphalt was compacted

should be compacted in a “ideal” temperature frame, which is

enough. The old machinery was robust and extremely uncom-

different for every asphalt mix. When compacting at very low

fortable, causing the craftsmen to feel every bump in the asphalt

temperature intervals, the rollers are simply crushing the stones

mat through their machines. Times have changed and so have

in the asphalt, damaging rather than compacting the asphalt layer.

the comfort standards for asphalt machines. While upgrading

If the mix temperature is still in the high temperature ranges, e.g.

the level of comfort and adding several new technologies to the machines, the sense of craftsmanship for the paving process has

FIG. 2 Temperature measurements using RFID temperature sensor tags during construction

in a sense, slipped away from the operators. At the same time, public clients such as municipalities, provinces and national road agencies (in the Netherlands: Rijkswaterstaat) have become more demanding asking for extended warranties on the constructed asphalt layers to ensure that the intended durability is achieved. However “proving that the new asphalt mat will be durable” presents several challenges. A mixture of non-destructive and destructive tests is used to show that the constructed layer meets the specifications. Nuclear density gauges are used to measure the density of the asphalt layer during construction. However this equipment is rather expensive and the measurements can be inaccurate depending on the type of asphalt and the layer thickness. Drilling cores after the asphalt mat has cooled down completely is another option. However, this method may lead



along with the use of RFID chips: the sensors have to be wirelessly connected with a reader at a distance of approximately maximum 20 centimetres. Not really much when the chips are moving through the asphalt layer under the pressure of the asphalt rollers. Jurian van de Vegt and Daan Brinkerink subsequently conducted their bachelor projects with ASPARi on the use of Fibre Optic sensors to measure temperature and strain during the construction process. These sensors use the speed of light to indicate temperature changes of the environment. The working principle of these sensors is as follows: in a Fibre Optic cable several gratings are made.These gratings are able to filter a certain amount of the spectrum of light what will be sent through the Fibre Optic cable. One cable contains a maximum of up to eight of these gratings and thus one cable can only contain eight sensors. As the cable gets strained the characteristics of the gratings change, whereby the spectrum of light sent back by the gratings slightly change in a linear way. FIG. 4 Example of an RFID temperature chip drilled out of the asphalt mat during density measurements post construction

above 140 °C, the asphalt is too hot to compact. Compacting at the higher temperature ranges causes the asphalt to “flow”

“These sensors will be monitored in the coming years to see if any extreme strain peaks occur which might lead to rutting or cracks in the roadbed.”

under the pressure of the rollers. Compaction is temperature dependent and we therefore have to know the temperature of

Notwithstanding the promising possibilities of measuring tem-

the asphalt mat constantly during compacting.

perature and strain during construction, Jurian’s and Daan’s pro-

Since we need to know the temperature of the asphalt during

jects both undertaken in a laboratory setting, highlighted several

construction, ASPARi developed Process Quality improvement

challenges. Firstly, the Fibre Optic cables are extremely fragile,

(PQi) monitoring system, including temperature measurements

they tend to break even quicker than the screen of your Smart-

using laser line scanners, infrared cameras and thermocouples.

phone. Fibres therefore must be protected in the rough asphalt

A laser line scanner is normally fixed to the asphalt paver and

industry. Secondly, the Fibre Bragg Gratings (FBG) are sensitive

measures the surface temperature of the asphalt mat just after

for two kinds of strain: mechanical strain and temperature strain.

paving. However, the temperature at the surface of the asphalt

For asphalt, the fibres can be strained mechanically (with heavy

mat is influenced by the environment: rain and wind, which

machinery, rising compaction rates, etc.) during significant tem-

causes rapid cooling of the asphalt surface. Therefore, the core

perature changes (the mix temperature decreases during the

temperature of the layer may be different from the surface tem-

cooling process). To measure temperature, the sensors have to

perature and may be more helpful for the decision: “to compact

be protected in a way that no mechanical strain can be transfer-

or not to compact”. Measuring the core temperature accurately

red onto the Fibre Optic Cable. Flexible steel tubing (1.5 mm

and consistently is challenging since asphalt paving occurs in an

FIG. 5 Example of light spectrum being transmitted by FBG sensors

environment with heavy machinery, rough handling and with mix temperatures as high as 180 °C. Measuring equipment must be able to survive under these circumstances.

LABORATORY EXPERIMENTS UNDERTAKEN BY CIVIL ENGINEERING STUDENTS Recent research of Sjon van Dijk (Bachelor Project) tested Radio Frequency Identification (RFID) chips for temperature measurements during asphalt compaction.These chips were shown to be breakable when the temperature of the asphalt becomes really hot (above 160 °C). A second, even bigger problem also comes


not deform under the weight of a mini drum roller of approxi-


mately 3.5 tons.

In the first week of December 2017, lessons learned in the labo-

The FBG sensors were successfully used to produce tempera-

ratory experiments were transferred to the construction pro-

ture cooling curves for the asphalt mixes studied. However, it

cess. Since this was the first test with FBG sensors outside the

also highlighted differences between the data measured with

laboratory, grooves were cut in the base layer into which the

thermocouples and the data measured by the FBG sensors. As

Fibre Optic Cables (with protection) were installed. The RFID

mentioned above, the FBG sensors can be set up to measure

chips were fixed to the top of the base layer and the thermo-

temperature and strain. To measure the strain changes in asphalt

couples were installed during the paving of the surfacing layer.

with FBG sensors the Fibre Optic Cable still has to be protec-

All three technologies were able to successfully register asphalt

ted but, the cable has to be attached to the protection material.

mix temperature during the actual construction process. While

Once attached, the FBGs are able to measure strain changes in

the RFID chips and thermocouples roughly showed the same

the host material (asphalt). In the laboratory experiments the

temperature data, the FBG sensors showed a delay in tempe-

fibres were covered by a plastic tube which was softened by

rature changes, meaning that the temperature gradient, because

the temperature of the asphalt during paving. When compaction

of the hot asphalt, was only seen after a while. This problem did

started, the protection tube was pressed onto the FBGs and the

not occur in the laboratory experiments. At two other spots in

protection material became attached to the FBG sensors.

the roadbed, FBG sensors were installed for the measurement

diameter) is very suitable for this purpose: it is flexible and does

of strain in the asphalt mat. These sensors will be monitored in

“There is still a long way to go if we are to make roads smarter with some form of sensor-based intelligence”

the coming years to see if any extreme strain peaks occur which might lead to rutting or cracks in the roadbed. While this project has shown that new sensors are a useful addi-

To check whether the FBGs were able to detect strain in an

tion to a rather traditional construction process, there still is a

asphalt beam, a four point bending test was undertaken. During

long way to go if we are to make roads smarter with some form

the four point bending test the strain in the asphalt beam can be

of sensor-based intelligence. We may just learn more about the

modelled using the force data of the equipment and the strain

behaviour of the asphalt layers during and after construction and

could be measured by the FBG sensors. In the end the sensors

in so doing, make our roads more durable.

were able to successfully detect strain in the asphalt beam. The

For further information or if you want to join the ASPARi unit

tests showed that the FBG’s were sensitive enough to show

on some exciting projects in the use of sensors in asphalt, please

extremes in the data that occurred as a result of stone particle

contact Seirgei Miller ( or Denis Maka-

rearrangement in the asphalt beam.

rov (

FIG. 6 Installation spots for sensors at the Boerderijweg




WHAT HAPPENED IN THE CIVIL ENGINEERING SECTOR RECENTLY? PHASE CHANGE MATERIALS IN HOMES AMSTERDAM NOORD 17 January 2018 During a large-scale renovation project, Ymere is testing Phase Change Material s(PCM). This sustainable material can absorb and release heat when the material changes from solid to liquid and vice versa. The PCM and a heat pump boiler provide a gas free underfloor heating system. During the renovation work, all homes are connected to district heating. The natural gas free housing block provides Ymere the opportunity to do trials, already looking into the future. PCM floors are made of cassettes of saline solutions that are able to store and release heat when required. The residents of the test houses have been able to enjoy the benefits for six

months now.This way, the PCM floor keeps the living rooms warmed up without continuously using the heat pump.Ymere is comparing the energy consumptions of the newly renovated houses and adjacent houses having a central-heating system. During cold November, the PCM homes were slightly more economic. In the coming period Ymere will be finding out how big the energy savings will really be. The renovated homes are part of a state-protected city and village view neighbourhood. For this reason, Ymere was not allowed to change the building exterior. Instead, they changed the interior drastically.The entire interior has been packed with insulation materials and all installation have been replaced. All measures caused the EU Energy Label to shift from G to A.

MAJOR MAINTENANCE TASK FOR DUTCH INFRASTRUCTURE 19 January 2018 Many Dutch bridges and tunnels have been built in the 1950s and now they are approaching the end of their lifespan. The highly increased age of the objects causes an increased chance of malfunctions. That is why Minister for Infrastructure and Water Management Cora Photography: Wikifrits

van Nieuwenhuizen has kicked off a

major maintenance operation that will rejuvenate, renew and make sustainable the existing infrastructure in the Netherlands in the coming decades. This is called the Programma Vervanging en Renovatie (EN: Replacement and Renovation Programme). The investment in the existing infrastructure are important to guarantee the reliability and availability of roads and waterways. Failures and malfunctions lead to social nuisance and economical damage. Growth of traffic intensity leads to an increased impact on the roads and waterways. Investing in the existing infrastructure is therefore particularly effective alongside the construction of new roads. The programme consists of about 40 projects spread across the Netherlands.

KCCA AND DEVELOP2BUILD ARE GOING TO TACKLE KAMPALA TRAFFIC CHAOS 8 January 2018 Kampala, the capital city of Uganda, has been struggling for years with enormous traffic problems and serious air pollution in the Central Business District. Together with the Kampala Capital City Authority (KCCA), Dutch consultancy firms Move Mobility and Goudappel have drawn up a mobility plan. Based on this, KCCA is developing a project plan with the support of Develop2Build (D2B) that will provide a solution for these problems. This project aims at an improved traffic flow, a healthier air quality, and more economic opportunities for the inhabitants. This is necessary since 1.5 Photography: columbustraffelmagazine/.nl

million commuters travel into the city

every day. The Central Business District has been struggling for years with enormous traffic problems, congestion, accidents with pedestrians, and serious air pollution due to emission of soot particles.Therefore, the project will mainly focus on redeveloping the central minibus station Old Taxi Park and it will create traffic-free zones for cyclists and pedestrians in the CBS.

BIM ALIVE ON SITE 12 January 2018 BIM is mainly used for planning and organisation of the construction process. But now, contractor M.J. de Nijs takes BIM to the construction site. 3D cameras in the boom of the crane deliver images that are turned into to the model for 4D BIM progress control. The cameras continuously take pictures of the site as soon as the crane makes a turning movement. Twice a day all pictures are sent to the server of Pix4D. Pix4D is a Swiss company having special software that compiles all images.The floor plan can be projected on this image compilation. The software also creates a point cloud


which is put in the BIM model. Therefore the cameras are equipped with GPS receivers, so that images can be made being so accurately that it can be used for measurements. This way the building production progress can be monitored. The created images can also be linked to digital plans and it can be used for quality controls. This way of monitoring is already tried using drones. It is however not always permitted to fly above construction sites. Contractor De Nijs is the first one ever to try this in the Netherlands. In Scandinavia and France some contractors are however trying this out too. The pilot is currently being carried out on the Steltloper project in Amsterdam, a building with 126 apartments on 19 storeys with a parking basement underneath.



In the latest years, mobility and logis-

temporal dynamics.

tics have become more important

The availability of relevant data contributes to and enables the

than ever before, especially for eco-

application of real-time traffic management and Intelligent Trans-

nomic growth. However, the ever-

port Systems (ITS). A major requirement for these applications

growing demand for transport can

is the availability of complete and consistent traffic state esti-

often not be fulfilled, as it is in many

mation. The traffic state includes all parameters that describe

cases much higher than supply. This

the prevailing traffic conditions, including parameters needed for

imbalance between demand and sup-

prediction.The current state estimates form the basis for (short-

ply leads to overuse of the existing road network and to wide-

term) prediction of the future traffic state of the network. This

spread congestion, high emissions and noise levels. In addition,

prediction leads to informed decisions on traffic control mea-

congestion has proven to be extremely costly for the national

sures to be implemented with a goal to prevent or minimize

economies. Adding road capacity to solve this problem is no lon-

congestion. The importance of an accurate traffic state estima-

ger a simple solution, as it comes at a high cost and suitable

tion is, thus, highlighted by the fact that an inaccurate estima-

available space is limited. Therefore, effective traffic management

tion will propagate through the decision support model, leading

becomes increasingly important to maximize the efficiency of

to an incorrect prediction of the (near-)future traffic state and

the existing road infrastructure.

to wrong conclusions regarding the appropriate traffic control

To achieve the goal of effective traffic management, it is impor-

measures to be used, as the short-term prediction of the future

tant that adequate information regarding the prevailing traf-

traffic state is a component of major importance for traffic con-

fic conditions is available, which is nowadays easier than ever

trol and ITS.

through the use of a vast and ever-increasing amount of data

The accurate estimation of the traffic state is not an easy task.

sources (e.g. induction loop detectors, floating car data, automa-

Required data is only partially available through sporadically

tic vehicle identification via Bluetooth etc.). These data sources

installed sensors in the road network or through traffic data

can provide information useful to traffic engineers, but the data

providers. Significant research has been conducted on the sub-

needs to be properly validated (as sensor measurements contain

ject and various methodologies have been suggested to improve

random and/or systematic errors/noise) and fused to succes-

traffic state estimation. It must be noted, however, that the majo-

sfully assess the prevailing traffic conditions and their spatial and

rity of related work deals with freeway networks. The intersec-


tions (regulated by traffic signals or unregulated) and the esti-

relationship between density and speed), as well as better cope

mation of the fractions of traffic flow turning to each direction,

with non-regular traffic conditions. These significant advantages

the increased complexity due to the higher number of routing

lead to the decision to follow a model-based approach in this

options available, the higher variation in the speeds of the vehi-


cles, the variation of road users and travel motives, as well as the

A model-based traffic state estimation method consists of three

relatively low density of sensors installed in urban networks are


the major factors that further increase the complexity of the problem.

1. A process model, used to compute and predict the state variables (e.g. density, speed). In the developed approach, Streamline is used, a framework incorporated in Omni-


TRANS by DAT.Mobility. Streamline features a dynamic

The term traffic state estimation refers to the estimation of all

traffic assignment model, as well as a powerful junction

traffic flow variables necessary to reproduce the traffic condi-

modelling module which enables accurate modelling of

tions on a link or a network, based on available traffic data. The

intersections, an essential element of urban networks.

difficulty in estimating the traffic state lies not only in the fact

2. An observation model, used to compute and predict from

that the data from the sensors is not enough to estimate all

these predicted state variables the expected measurement

unknown traffic variables, but also in the fact that the sensor

values to be received from the sensors, considering the

data is affected by noise.

uncertainties of the process (e.g. density-flow and density-

Available estimation methods include data-driven methods,

speed relationships) and the measurements (e.g. due to

which use basic statistics, historical data and interpolation based

inefficiencies of the sensors).

on the sensor data, as well as model-based methods, which also

3. A data assimilation/fusion technique, used to estimate the

take traffic flow dynamics into account. While the data-driven

most probable traffic state using both the model predicti-

methods are less complex and computationally expensive than

ons and the actual measurements coming from the sensors.

model-based methods, the latter are more accurate and offer

There are various data assimilation techniques, employing

the opportunity for full traffic state estimation (e.g. including

either simple or more sophisticated algorithms. For the

parameters that are impossible to physically measure, such

developed approach, the Extended Kalman Filter (EKF)

as the fundamental diagram parameters, which determine the

was selected, because of its suitability for implementation



on non-linear systems and its computational efficiency. In Figure 1, a schematic procedure describing traffic state estimation with a recursive data assimilation method (such as Kalman Filtering) is provided. The method consists of prediction and correction steps, based on the measurements received from the sensors in each time step. The process model describes the evolution of the system state (density, speed). The observation model relates the system state to the observations. The aim of the data assimilation method is to make an optimal estimation of the system state through the use of all new measurements that were made available between the previous and the current time step. For each discrete time step, first a prediction of the system state is made, based on the process model and the last available esti-

FIG. 2 The majority of related work deals with freeway networks

mate. In the developed solution, the prediction of the state is

leads to a more accurate and robust traffic state estimation. The

received from Streamline. Based on this prediction, the observa-

developed model is designed with the fusion of speed and flow

tion model predicts the values of the measurements expected to

measurements in mind, but it can be expanded to use any type

be received from the sensors. In the correction step that follows,

of traffic data, provided that the observation model is defined

the predicted system state is corrected with an optimal weigh-


ting factor, proportional to the difference (errors Et) between the predicted measurement values and the actual measurement


values received from the sensors. The optimal weighting factor

The validation scheme selected for this specific model is based

is determined in terms of minimizing state estimation errors. In

on artificial measurements.The reason is that the use of artificial

the Kalman Filter, this weighting factor is called “Kalman gain”. It

measurements provides the necessary controlled environment

works as a regulator between the “a priori” estimate of the state

and the opportunity to examine the impact each uncertainty

and the received measurement. Based on the measurements

parameter has on the accuracy of the estimation. Therefore, the

received, the “knowledge” it has accumulated from the previous

use of artificial measurements provides more options and flexi-

time steps and the uncertainties of the process and measure-

bility for the validation of the method.

ment, it decides on which of the two values to give more weight

The validation process begins by testing the effect each one

to: the estimate or the measurement. This procedure iteratively

uncertainty parameter has on the estimation. The uncertainty

provides state estimates at each time step.

parameters in the developed model are the following:

Most approaches in traffic state estimation use one source of

• Accuracy of measurement values (uncertainty about the

traffic data/measurements. A possible reason is the complexity

actual values received, error on the measurements due to

of fusing data from different types of sensors into one model,

inefficiencies of the sensors)

as each data source can possibly have different spatio-temporal

• Availability of measurements

resolutions (e.g. Eulerian/Langrangian coordinates). Additionally,

• Correctness of the OD matrix used. (The OD matrix con-

it could be difficult to integrate various types of sensor data (e.g.

tains information on traffic demand: the number of trips

speed, flow, travel time etc.) into the flow model due to nonline-

going from each origin to each destination)

arities in traffic flow. However, fusing data from multiple sources FIG. 1 Schematic representation of the prediction-correction data assimilation method

• Fundamental diagram parameters (correct or not, variable or fixed) As a next step, combinations of the above parameters are made, in order to examine the combined effect of the parameters to the accuracy of state estimation, followed by a final test with all uncertainty parameters enabled, as would be the case when working with a real network and measurements. The performance evaluation is achieved through the calculation of error parameters, such as the root mean square error (RMSE) and the mean absolute percentage error (MAPE) between estimated and “ground truth” values.


FIG. 3 Sample results of the state estimation


improve over time and eventually converge to the ground truth

The model could satisfactorily estimate the state variables (den-

value. The standard deviations which control the variation allo-

sities and speeds) of all links of the network, as the average error

wed per time step for each fundamental diagram parameter

values of all tests were at an acceptable level. Estimation impro-

could be increased in order to achieve faster convergence of

ves over time, as the model “learns� through the fusion of mea-

the free flow speed. However, a high standard deviation value

surements. An increasing uncertainty level of the system leads to

would lead to more nervous behavior of the estimated value of

a reduced rate of improvement.The individual tests showed that

the free flow speed, possibly leading to a higher average error

accuracy of the measurements (uncertainty and error on the

over time. Finally, the inclusion of a warm-up phase, to allow

measurements) is the parameter with the highest impact on the

the parameters to approach their actual values, is recommended

results, followed by the inaccuracy of the fundamental diagram

when possible.

parameters and the inaccuracy of the OD matrix. Combinations

FIG. 4 The imbalance between demand and supply leads to overuse of the existing road network

of these parameters in most (but not all) cases led to an increased combined impact on the state estimation. From the analysis of the most problematic links in each test, it was observed that an inaccurate OD matrix proved to have a higher impact on the estimation of the densities of links connected to a centroid (destination/origin). In addition, in tests with higher uncertainty it was observed that state estimation of links situated on parts of the network where no measurements were available did not improve over time, underlining the importance of the number of measurement points, as well as their position on the network. Among the fundamental diagram parameters, the free flow speed has the most significant impact on the estimation of the speeds and consequently the densities. In fact, the model succeeds in improving the estimate of the free flow speed over time but does not perform equally well in the estimation of the other fundamental parameters (speed at capacity and capacity per lane). The improvement in the estimation of the free flow speed proved to be independent of the initial values set, meaning that even the values starting further off the ground truth value




HAITSMA BETON SUPPLIED 80 HUGE HIP BEAMS FOR NEW FLYOVERS Author: Bert van den Berg, Hendrik Herder, Pieter de Boer & Mente Bonestroo

Starting from the 10th of July 2017, no fewer than 80 huge prefab

to the west in the new interchange with multilevel intersections.

HIP beams from Haitsma Beton from the Frisian town Koot-

The underlying infrastructure that was previously connected

stertille were installed at the Joure Interchange for the two new

to the roundabout is accessed on site by a new exit and level

flyovers in a new intersection in the A6/A7. The largest beams


were not less then 50 metres long. The last of these beams was

Rijkswaterstaat (Public Works), the province of Friesland and

installed on the 22nd of July 2017. In the media, there was a lot of

the municipality De Fryske Marren collaborated on improving

positive attention for his huge project. Even special “viewing eve-

Friesland’s accessibility via Joure. The A7 and A6 now meet in

nings” were organised, at which project employees were availa-

a new interchange with multilevel intersections. Haitsma Beton

ble on location to provide explanations and answer questions

supplied beams for not less then seven structures, including

from interested parties. Two grandstands were built on the Has-

two large flyovers. The flyovers have a 450-metre curve radius

kerhorne side of the A6, so that the interested could watch this

and each flyover is made up of five fields with eight beams. The

special logistical operation live. There was a conspicious amount

largest of the spans is 50 metres long.The contracting firm Gebr.

of public interest in the evening and night-time installation. On

van der Lee built the interchange.

some of these evenings there were as many as 500 people to see the assembly. It was also possible to follow the work live


by means of a number of webcams at,

Mente Bonestroo is Stakeholder Manager with Gebr. van der

and regular updates and beautiful action photos could be seen

Lee. “Rijkswaterstaat uses Integrated Project Management (IPM).

at the Facebook page “Knooppunt Joure” throughout the whole

This also involves stakeholder management to keep the relati-


onship with the surrounding area and stakeholders in balance

Saturday the 14th of October 2017 marked the end of the fami-

throughout the whole project. As the stakeholder manager, I

liar roundabout at the Joure Interchange, which long has pro-

take care of the communication with the interested parties, I

vided the connection between the A6 and A7 motorways. This

arrange the necessary permits, take care of the complaint settle-

was the last motorway roundabout in the Netherlands. From

ment and I supply the cables and pipes.” He emphasises the huge

that date, traffic from the two motorways meets slightly more

logistical challenge involved in getting the 80 beams into place


INTERIM STORAGE First, Haitsma Beton brought the beams for the four fields by road to a temporary storage location in Heerenveen. From there, the beams were taken to Joure and put in their final places. Bonestroo indicates: “We transported the beams that were needed for the six fields on the east side to the Sint Nicolaasga exit and turned the convoi around there. Haitsma Beton worked together with the company Sarens to have them lifted into place. Sarens used two 700-ton cranes to hoist the largest of the beams.”

HIP BEAMS The HIP beam is an I-profile beam developed by Haitsma Beton for the civil engineering market. Crosswise restressing, wet conFIG. 2 Viewing evenings were organised during installation work

nections or a topping can be applied. A topping was used for the

in just two weeks, without hindering traffic: “We installed the

Joure Interchange. To be able to follow the curve radius of the

beams overnight. In week 28 of 2017, we carried out the instal-

flyovers, Gebr. van der Lee and Haitsma Beton came up with a

lation above and alongside the western lane of the A6, the week

solution jointly, which means costumization. Bert van den Berg,

afterwards above and alongside the eastern lane. Of course, the

Project Leader with Haitsma Beton, explains: “At the top of the

lanes involved were closed during the installation. We worked

edge beams, there is a variable flap which follows the radius of

with a 3-0 system. The traffic in one direction would then have

the flyover. Gebr. van der Lee then attached its composite edge

one lane, while two lanes were available in the other direction

elements to the beams, so that the flyovers look as though they

for traffic. Fortunately, all the lanes were open again during the

are curved horizontally.

rush-hour times so that the traffic was disrupted as less as pos-

This solution is far cheaper than a horizontally-curved box gir-

sible. By day, the 3-0 system was reintroduced to be able to apply

der deck, for instance.”

the reinforcement and the topping on the previously installed beams. This all meant we had to convert the traffic lanes no less


than four times a day.You will understand that this kept us quite

There are two flyovers. One flyover consists of four fields of

busy. Then there were also brief closures at night when we had

approx. 40 metres and one field of approx. 30 metres. The other

to hoist beams across the road to the other side.”

flyover, the largest, contains three fields of approx. 50 metres and

FIG. 3 Installation over the closed lanes



two fields of approx. 36 metres.

ces of the cross sections that are important for the lateral force.

The longest span of 50 metres is explained in more detail. The

The loads that are present when the beams work together as a

cross-section contains HIP beams of 1.5 metres working width,

result of applying the topping were entered into the EEM models.

which are 2 metres high.To make the curve radius of the viaduct

The design criteria were:

possible, the flaps on the top side have a horizontal curve. The

• Design lifespan of 100 years

underside of the deck is straight. These are prestressed bridge

• ROK 1.2

beams. There are 64 prestressing strands per beam, ø15.7, of

• CC3

which 12 are guided through a positioner. These strands are

• The resting load consists of asphalt, kerbs and edge loading

located at one third and two third of the length of the HIP beam.

as a result of a railing, decorative edge and guide rail

With this span, box girders are often prescribed due to the

• Lane width 10.33 metres

relatively low construction height. At the Joure Interchange, this

• Fatigue category 1

is not the case and HIP beams are used that have a greater con-

• Collision load

struction height than box girders.

These loads were used to determine the moments, lateral forces

For the concrete mix, it was decided to use a strength class of

and torsion moments for the beams. The beams were dimensi-

C60/75. For the tightening strength, a value of C35/45 was cho-

oned for this determination, together with the forces from the

sen. To have the elements work together, a topping of 200 mm

prestressing, the own weight of the beam and the topping. The

thick was applied with a strength of C35/45. Before applying the

reinforcement in the topping was calculated using the lateral

topping, the top joints were closed with permanent formwork.

moments from the EEM models. The reactive forces from the

These joints are approx. 40 mm wide.

models were used to determine the bearing blocks.

For the beams, the own weight is the primary load in this span. It forms 55% of the load that needs to be taken up with prestres-


sing load.The remaining resting load, about 12%, and mobile load

Haitsma Beton was also commissioned by Gebr. van der Lee

of 33% are less dominant compared to normal shorter decks.

to deliver all the prefab piles for the engineered structures.

All the spans were considered in the calculation. All the decks

These were all square 450-mm piles from 15.75 to 21 metres in

were schematised as a beam grate in which the long beams and

length. Bonestroo: “Selecting Haitsma Beton was partially a con-

cross beams were entered as members and the topping as an

sequence of their favourable price-quality ratio and of course

isotropic plate, after which calculations were made using an EEM

the fact that they are here in the vicinity (Kootstertille). There

program.The stiffness and torsional stiffnesses in the longitudinal

are also very few companies that can manufacture such huge

and transverse directions were needed in the part of the surfa-


FIG. 4 Illustration of the cross section of the HIP beam



major topics that are very relevant to the programme in the

Eva Blokhuis, 29 years old and I

upcoming year. One of the main topics is the upcoming accre-

have my Master’s degree in Educa-

ditation which allows us to get accredited for another six years.

tional Science and Technology; so I

This is, obviously, very important for the programme to conti-

am an educationalist.

nue, and to keep its good name within the Netherlands, Europe

Since the 15th of August I am in

and the world in general. The other main topic is changing the

office as the program coordinator

Master’s curriculum from 7.5 EC courses to 5 EC courses.

for both the Bachelor programme

This requires a complete transformation of the curriculum, a

and the Master programmes of

reviewing of the profiles and a lot of effort from all the tracks,

Civil Engineering. I am the succes-

teachers, and supporting staff. The new or transformed courses

sor of Sander Siebelink, whom most of you knew pretty well.

need to be linked to the end terms of the programmes, which

But this is not the only change within the programme staff. Next

needs to be approved by the exam board, before it can be imple-

to a new coordinator, there is a new programme director: Seir-

mented. This is a complex, but hopefully rewarding task in which

gei Miller. Besides it being new and exciting to start and roll

we all have to work together.

into a pretty well organized programme, we get the chance to

These two topics have my main focus right now, and I look for-

choose our own direction in cooperation with students, tea-

ward to the development in both areas. I will keep everyone

chers and other supporting staff. It is challenging, but at the same

posted if there is any relevant news in either of the two projects.

time, because we are both new, it offers us the change to start

To conclude, I want all of you to know that my door is open if

with a clean slate and a fresh look on things.

having any practical questions, feedback, remarks on the pro-

Next to being the programme coordinator, I will fulfill a roll as

gramme. Additionally, if you have question of which you do not

the module coordinator for module 12; the Bachelor thesis, I will

know where to pose them; you can find me in BH 115 in the

contribute to the implementation of Canvas next school year,


and I have the opportunity to participate in the organization of certain events, like the Kick-In for example.


I am really looking forward in fulfilling my role in the programme

Eva Blokhuis

and meeting some, and preferably most, of you. There are some




The last years, we faced more and more extreme weather con-

the construction fault then the heat itself.

ditions in the world.Whether it is climate change or not, we had

What might be a problem within buildings, is the ventilation

to deal with them. This winter This winter we had no ick layers

and cooling. A lot of extra power is needed to keep a workable

of snow. However, on Tuesday 18 January, a very heavy storm

environment. In the USA, several years the electricity flow was

came over our tiny country. Warning level code red, gusts of

pushed up beyond the capacity limit, often resulting in electricity

more than 120 kilometers per hour, people that were blown

supply failure. Most notably was the summer of 2003, when a

away, roofs that were suddenly gone, and an enormous amount

system failure resulted in the largest blackout in U.S. history,

of short videos. A storm with large impact on our society and

leaving as many as 50 million people without power for several

civil engineering. But what if this summer is more extreme than

days, all due to electricity demand for air conditioning.

last winter. What if we would face an extreme hot summer?



In structural engineering, heat should not be a very big problem.

In The Netherlands we know, if weather is different than ‘nor-

With the current regulations on fire safety, only temperatures

mal’, the train system fails. Leaves on the track, snow in the swit-

where we all will die lead directly to collapses. However, the

ches, wind making bridges and railways unsafe, it is commonly

heat in combination with construction mistakes can have big

known. Also heat will make affect rail traffic. Due to the heat,

consequences. In the earlier article about the collapse of the

rail tracks expand and start deflecting, with buckling, in this case

Eindhoven Airport Parking, we told how the construction fault

called sun kink, as result. This will already occur from 25 degrees

in combination with heat, led to the collapse. Such events might

Celsius. This is probably the reason most of the Italian railway

happen with other constructions as well, but is more because of

tracks are white. White tracks reflect sunlight and therefore are

FIG. 1 Metled asphalt in India (yes, this once were straight lines)

less heated.Whether painting tracks white has a significant effect is however still discussed. Most vulnerable structures for transportation are bridges. Due to the expansion and deflection, both railway and road bridges can get stuck. In hot summer days, lots of bridges across The Netherlands are cooled with water, to prevent this. And if it becomes really hot, asphalt will start deforming of ‘melting’. A good sun on dark asphalt, together with heat from the bottom of cars and due to the resistance of braking cars, and there is your highway where 70 kilometers an hour is the maximum safe speed.



1. Safety and prevention of irreversible damage: Especially in

And when you have already started booking a trip to Australia

areas with a high peat in the subsurface, safety can also

(during our summer, it is winter over there) I will have some

be at risk due to drought. An example is the collapse of

bad news for you. The heat will lead to thinner air, which makes

the peat quay at Wilnis in 2003. Irreversible damage can

climbing much harder for air planes. Also landing will be a lot

also occur due to peat oxidation and latch. But also nature

harder, resulting in delays and cancellations. But in the end your

bound to soil conditions is part of the highest priority

flight will probably depart. Large aircraft are designed to fly


with temperatures up to 50 degrees Celsius. At that point there

2. Utilities: Both drink water availability and energy supply

will be more problems at the airport. Think of automated lug-

are of course very important the keep The Netherlands

gage systems, air conditioning, or maybe even the runway. On

running. When supply is however secured, drink water and

Washington’s Reagan National Airport, the tarmac layer started

energy supply are part of category 4.

melting at 37 degrees Celsius in combination with a heavy bra-

3. Small-scale high-quality use: This category is an exception

king airplane. It is for a reason that countries in the Middle East,

to the position that agriculture and other economic needs

and some high-altitude airports in South America, often sche-

generally take in category 4.These are crops where there is

dule long flights for cooler times.

a risk for a total failure of the harvest due to water shortages, while a relatively small amount of water can prevent


major damage.

A heat wave means that water is needed for cooling. However,

4. Other interests: In this category are all other interests, like

it often comes with a precipitation deficit. Fresh water is one of

shipping, industry, recreation, fishing and reversible damage

the most important things in life. But next to drink water, it has a

to nature.

lot of other functions.What if there is a shortage of fresh water?

Further prioritization within category 1 and 2 are determined

The Netherlands is probably one of the best countries is hand-

on a national level.Within category 3 and 4, further prioritization

ling a lot of water. But also for a shortage, we are well prepared.

is based on minimization of economic social damage. Also priori-

A national scenario for water distribution and drought is ready

tization by regional elaboration is possible for category 3 and 4.

for use. The most important aspect: A legally defined displace-

And finally the biggest problem of a heat wave: all chocolate

ment range (in Dutch: verdringingsreeks) with the priority of

sprinkles (in Dutch: hagelslag) melted together to one big sprin-

fresh water:

kle. Now try to get that out of the package on your slice of bread.

FIG. 2 Extreme low water level in the Waal at Nijmege in October 2015



Conceptueel 27-1  
Conceptueel 27-1