Top ten trends of 2023 into 2024

Direct by Design

Top 10 trends and events of 2023 to influence 2024 and beyond Shani Wallis of TunnelTalk reporting

January 2024

10. Education

9. Technological advances

The objectives of the next generation of professionals are decidedly different to generations of the past. As Jamal Rostami of Colorado School of Mines said at a recent 2023 conference: “The new generation of professionals are not just looking for a job. They want to make a difference and our underground projects make a difference.”

The quests for the holy grails in our industry continue – to ‘see’ inside the rock mass; to excavate faster, safer and to better quality; to develop the ultimate universal TBM are among the many – but to what end? All are laudable, with the quest for safety paramount in all we do, and great strides have been made in these regards over recent years and by harnessing new advanced technologies. Quality now, when built by experienced contractors and crews and designed and supervised adequately and managed well by clients is superb, with much needed where any one of these vital links fails or faulters. To excavate faster brings financial gain in closing that cost centre early, but all must be looked at in the round to make a holistic difference. What good to save one month or one year on the underground excavation element of an infrastructure project for it to be lost in the finishing and inauguration phases. What good excavation speed on projects that have taken decades to bring to the realisation stage, decades in the feasibility and preliminary design phase, and then years on years in the final fitout and commissioning phases. This dilemma was most recently illustrated on the Crossrail project in London where excavation of 27km of twin tube railway running tunnels and eight underground stations under the heart of one of the oldest, most dense, and most expensive urban complexes in the world, was completed in 3.5 years (2012 to 2016) on a project that took 14 years from Government approval in 2008 to fully opened in 2022, included seven years after completion of all excavation to start of services. Keep striving for the holy grails but let us not make our bit of greater projects a myopic focus.

If you are young and looking for direction or older and mentoring a young ward, search out courses and training centres to create a career in underground engineering construction using these for starters: • • • • • • •

ITA-CET - ITA Committee for Education and Training Colorado School of Mines - Underground Construction and Tunnel Engineering Graz University of Technology - Programmes in Construction, Rehabilitation and Operation of NATMand TBM-Tunnels Stuttgart University of Applied Sciences - Civil Engineering/Geotechnical Engineering/Tunnel Construction University of Technology, Sydney - Tunnelling and underground engineering program and download the brochure TunnelSkills - Training Group, UK SWAYAM education programme, India - Course on Rock Mechanics and Tunneling

8. Conference and exhibitions 2023 was mega year for industry gatherings with many of the main biennial and triennial events coinciding in 2023.

These were the stand outs for the industry: • • • • • • • • • •

Jan 2023 - bC bauma CONEXPO India - Noida Exhibition Centre, Delhi, India Apr 2023 - WTC World Tunnel Congress and 49th ITA General Assembly - Athens, Greece Jun 2023 - RETC, Rapid Excavation and Tunneling Conference - Boston, Massachusetts, USA Sep 2023 - Nordic Grouting Symposium - Stockholm, Sweden Oct 2023 - AFTES Tunnelling Congress - Paris, France Oct 2023 - Ground Freezing Symposium - London, UK Nov 2023 - ACUUS Underground Space Conference - Singapore Nov 2023 - Australasia Conference - Auckland, New Zealand Nov 2023 - STUVA Expo - Munich, Germany Nov 2023 - Tunnelling Asia Conference and ITA Awards Presentations

These are the standout events for 2024: • • • •

Apr 2024 - WTC World Tunnel Congress and 50th ITA General Assembly - Shenzhen, China Jun 2024 - NAT North American Tunnelling - Nashville, Tennessee, USA Oct 2024 - BTS British Tunnelling Society Conference - London, UK Dec 2024 - bC bauma CONEXPO India - Noida Exhibition Centre, Delhi, India

Send notice of your industry events and conferences and we will add them to our list.

7. National tunnelling associations

5. Social Media cove

Currently there are 79 Member Nations of the ITA, International Tunnelling and Underground Space Association, the newest, Pakistan, welcomed at the 2023 ITA General Assembly in Athens, Greece. To be a Member Nation of the Association, a nation must first have establish a national tunnelling association or society. Know if your home nation and country of employment is a Member Nation of ITA and click on the national logos to get involved.

The Covid pandemic cancellation conferences, meetings and events for years changed completely the world a While we may think things are back to n the fundamental changes remain and o the ubiquitous use of online video calls, v and the live streaming of conference lectures. These have expanded the r previously region events and multiplied way beyond the in-person delegate atten the organisations that have harnessed the best advantage have been: •

•

British Tunnelling Society - Recordings meeting lectures on YouTube and livest January meeting on 18 Jan 2024 on gro on the Paris Metro extension project ITA Awards – Live streaming and record sessions and roundtable and panel disc

4. Industry award wi

Together with recording project milesto outstanding industry individuals, achi projects is an oxygen that keeps the engaged and advancing. There are so award recognition programmes and the the most well established.

•

• • •

ITA - International Tunnelling and Under Association Tunnelling Awards – Winne series and the proceedings of previous TAC - Tunnelling Association of Canada 2023 awardees and those of previous y BTS - British Tunnelling Society – Jame for outstanding industry contribution UCA – Underground Construction Asso USA Awards – Awardees of 2022 and o

Add others to these and nominate technical developments and mento prestigious industry gongs.

6. Industry records and project milestones

The longest, largest, fastest, most difficult provide the industry’s benchmarks of achievement. The Marmaray immersed tube railway across the Bosphorus; the Hong Kong–Zhuhai–Macau immersed tube; the Busan–Geoje crossing in South Korea; the BART subway link across San Francisco Bay in the USA, will all be eclipsed by the current 18km long road and railway fixed link across the Fehmarnbelt between Denmark and Germany. The drill+blast Seikan undersea rail link in Japan; the Eurotunnel railway under the Channel between the UK and France; the drill+blast Orange-Fish water transfer tunnel in South Africa and the deep Gotthard baseline railway under the Swiss Alps, are being challenged by the Brenner base railway between Austria and Italy.

Each year more industry records tumble. In November 2023, a 4.9m i.d. segmentally lined TBM drive for the Woodsmith potash mine in the UK claimed the record as the longest single heading drive at more than 25.8km long. Other long distance singleheading segmentally lined TBM drives are the two 10m diameter TBMs excavating the 44km long AMR water conveyance tunnel in India from the two portals only. With one of the TBM currently at more than 23km and the other at 13km from the portal, the AMR project could also class as one of the most difficult long-distance TBM drive projects currently in the world. A real industry saga. For news on these and other record setting projects see the TunnelTalk Annual Review magazines from 2010 to 2021.

2

TunnelTalk is looking forward to meeting in Shenzhen in April. Now is the time to for you trip and on that score there is go China. China is now trialing no-visa-need visitors from six countries - France, Germ Netherlands, Spain and Malaysia. For e getting our visas will take time and now is t knowing what is required and getting all t in order to avoid disappointment and ge before buying long distance airline ticket non-refundable hotel accommodation. W there, all being well prepared, and with ready to celebrate the 50th Anniversary o annual ITA congresses and other events h line through many of our professional car

erage

3. Sustainability

of gatherings, more than 1-2 as we knew it. normal many of one of these is virtual meetings e sessions and reach of these d the audience ndees. Some of e possibilities to

Putting flesh on the bones of what the this actually means and how it applies to and influences the underground construction industry is a current focus. An interesting point was added to the discussion at a recent conference, to include the banking system to the 17 sustainable development goals, SDGs, of the United Nations. Funding and financing institutions impact infrastructure development decisions across the world, and underground infrastructure impacts the attaining of practically all 17 of the UN SDGs.

of its monthly treaming of the ound freezing

dings of technical cussions

inners

ones, honouring ievements and industry vital, many different ese are some of

rground Space ers of the 2023 s series a Awards – years es Clark Medal

ociation of the of 2018

your projects, ors for these

all at the WTC start planning ood news from ded waivers for many, Italy, the everyone else the time to start the paperwork et the visa well ts and booking We will see you everyone also of the ITA. The have charted a reers.

The ITA has engaged with the AIIB, Asia Infrastructure Investment Bank, to bring the attention of funding institutions to the underground dimension and its vital importance in the grand scheme of things. Click the image to watch the presentation.

Arnold Dix, current President of the ITA, International Tunnelling and Underground Space Association, gave a keynote on exactly how the underground construction industry is a lynch pin connecting all 17 of the SDGs and including banking and finance if it were added as the 18th. Click the image to access the Dix keynote.

3

eliminating cement cement from from the the mix. mix. active geology, geology, and and in in his his pre pr eliminating active active active geology, geology, and and in inhis his hispresentation presentation presentation geology, in Whenactive describing theand evolution of the (right) meets with Professor Iyer requi Varun Kedia Kedia of of Argentium Argentium sp Varun spo Varun Varun Kedia Kedia of of Argentium Argentium spoke spoke of of the the Varun Kedia of Argentium spoke of the diameters of Herrenknecht TBMs from geneff Nitin Garg Garg of of Herrenknecht Herrenknecht confirmed Nitin confirmed company’s tools tools designed designed rg g of of of Herrenknecht Herrenknecht Herrenknecht confirmed confirmed confirmed company’s g company’s company’s tools tools designed designed for for for coping coping company’s tools designed coping 6m to more than 17m and potentially up to 18-19m diameter, production compared that all all the the company’s company’s TBMs TBMs ordered ordered for deformations that for with high high deformations deformations inc inc he company’s company’sTBMs TBMs TBMsordered ordered orderedfor for for with ee company’s with with high high deformations deformations including including its its reminded with high including its Gen. Sharman of TAI, chair of the session, whenDexter the amoun the India India market market will will be beLt.manufactured manufactured the super more rockbolt.

Dexter GF a market market market will will will be be be manufactured manufactured manufactured super rockbolt.

GF super super rockbolt. rockbolt.

Dexter Dexter GFRP GFRP rebar rebar super rockbolt.

Dexter GFRP rebar the that TBMs are now more than three times design GFRP. and delivered delivered to to site site from from itsaudience expanding and its expanding has been been wellwith known for 20 20 vered ered to to tosite site sitefrom from fromits its itsexpanding expanding expanding has well known for ered has has been been well well known known for for 20-30 20-30 years years has been well known for 20-30 years the height the room we were sitting in - at about 5.5mWith suburbs withtwin twin 4.7km longof three-lane With suburbs with long three-lane e.

With suburbs with twin 4.7km long three-lane burbs with twin long three-lane factory in Chennai.

Chennai.

No 4.7km new TBMs will factory in No new TBMs will for reinforcing the soft eyes ne. n. Chennai.

Chennai.

Chennai.

No No 4.7km new new TBMs TBMs TBMs will will for reinforcing the soft eyes No new will for for reinforcing reinforcing reinforcing the the soft soft soft eyes eyes eyes for forwhen TBM TBMstanding in for for TBM 6m to ceiling – the astonishing size ater-totunnels. from Terratec alsofloor remains popular The merits of using po ter-to-from tunnels.

Terratec also remains popular ater-totunnels.

Terratec also remains popular nels.

Terratec also remains popular be be imported imported from factories in either either factories in break-outs and break-ins break-ins a orted rted from from factories factories factories in in either either either break-outs and an rted in break-outs break-outs and and break-ins break-ins break-ins and and in in his his his break-outs and and in front of an assembled TBM on in the segmentally lined 50lt/1m. among the TBM suppliers to the metro were detailed in the 0lt/1m. among the TBM suppliers to the metro 0lt/1m. among the TBM suppliers to the metro ong the TBM suppliers to the metro Germany or China, significantly reducing Germany or China, significantly reducing presentation Pierre Hoffman yor or orChina, China, China,significantly significantly significantlyreducing reducing reducing presentation Pierre Hoffman presentation presentation Pierre Pierre Hoffman Hoffman introduce introduce presentation Pierre Hoffman introduce tunnel it has excavated.

00,000 sector. the qualities of micro 0,000 sector.

00,000 sector. tor. the transportation transportation time, costs, costs,the and CO2 time, and CO2 the growing growing application of portation portationtime, time, time,There costs, costs,and and and CO2 CO2anythingthe the application of portation costs, CO2 the the growing growing application application of of of GFRP GFRP GFRP as as as growing application is rarely truly original or unique in the honest sense of 10m carbon-steel fibre whi of 10m of 10m emissions of shipping machines across emissions of shipping machines across permanent reinforcement of ofshipping shipping shippingmachines machines machines across across permanent reinforcement sssof across permanent permanent reinforcement reinforcement elements elements permanent reinforcement elements of discussion the word. Heavens, da Vinci was thinking ofconfirmed helicopters Terratec on its stand that it has the order to wo-part and in crack There was much discussion through o-part wo-part There discussion through There was much discussion through ere through Leonardo the world. world. alsomuch provides jobs and the ItItwas also provides jobs and particularly in fibreresistance reinforcedps d. d. ItItItwas also alsomuch provides provides jobs jobs and and and particularly fibre reinforced d. also provides jobs particularly particularly in in fibre fibrereinforced reinforced reinforced segmental segmental particularly in fibre segmental and submarines, and developed technical drawings of how they manufacture and supply the two 14.2m diameter TBMs ions by by Precision Drawell the conference of dealing with highly ons by ons by the conference of dealing with highly the conference of dealing with highly conference of dealing with highly opportunities for the India workforce. opportunities for the India workforce. linings were extra rebar st s TunnelTalk Editor Shani Wallis nities ities for for the the the India India India workforce. workforce. linings were extra rebar TunnelTalk Editor Shani Wallis ties for workforce. linings linings were were extra extra rebar rebar rebar strength strength is GoregaonTunnelTalk TunnelTalk Editor EditorShani Shani Shani Wallis Wallis linings were extra strength isis Editor Wallis would/could work,TunnelTalk centuries before they were finally ‘invented’.

So required by the J Kumar/NCC JV for the GMLR future. n active geology, and in his presentation active geology, and in his presentation active geology, and in his presentation ve geology, and in his presentation When describing the evolution of the When describing the Iyer evolution of thefor required for for hybrid hybrid applicatio applicatio (right) meets with Professor Professor Iyer escribing escribing the the evolution evolution evolution of of of the the the (right) required (right) meets with Iyer scribing the required required for for hybrid hybrid applications. applications.

GFRP GFRP (right) (right) meets meets with with Professor Professor Iyer Iyer required hybrid applications.

GFRP meets with Professor each new project in the underground construction industry does Mulund link roadof to connect Mumbai’s western and eastern Varun Kedia ofArgentium Argentium spoke of the Varun of spoke the Varun Kedia of Argentium spoke of the of Argentium spoke diameters ofKedia Herrenknecht TBMs from of Herrenknecht TBMs from generates 60-70% 60-70% less less CO C s of of ofKedia Herrenknecht Herrenknecht TBMs TBMs from fromof the diameters generates ssun Herrenknecht TBMs from in in its its its generates generates 60-70% 60-70% less less less CO CO CO222 in generates 60-70% not have to reinvent the wheel.

It has been tried before, it has been nfirmed firmed firmed company’s tools designed for coping company’s tools designed for coping company’s tools designed for coping mpany’s tools coping 6mto tomore morethan than 17m and potentially up to 18-19m diameter, 6m 17m and potentially up to 18-19m diameter, production compared to steel rebar and the re ore rethan than than17m 17m 17m and anddesigned potentially potentiallyfor up upto to to 18-19m 18-19mdiameter, diameter, diameter, production compared to steel rebar and the re re and potentially up 18-19m production production compared compared to tosteel steel steel rebar rebarand and andthe the thereduction reduction reductionisis is production to rebar References ered for deformations thought of before, and the real experiences arecompared there in the records edhigh for red for with high deformations deformations including its reminded with high including its with high deformations including its h including its reminded Lt. Gen. Gen. Sharman of TAI, chair of the session, reminded Lt. Sharman of TAI, chair of the session, more when the the amount amount of of material material can can be be redu redu Sharman Sharman of ofTAI, TAI, TAI,chair chair chairof of of the thesession, session, session, reminded reminded more when Sharman of the more more when when the the amount amount of of material material can can be be reduced reduced in in the the more when the amount of material can be reduced in the actured ctured and the archives to share that knowledge, knowhow and hard ctured super rockbolt. rockbolt.

Dexter GFRP rebarthree super Dexter rebar super rockbolt.

GFRP rebar per rebar the audience that TBMs TBMs are nowGFRP morelessons than three times times the audience that are now more than design with with GFRP. GFRP. ence ence that thatTBMs TBMs TBMsDexter are arenow now nowGFRP more morethan than thanthree three three times times design nce rockbolt. that are more times • ITA - Internationa design design with withDexter GFRP. GFRP. design with GFRP. anding anding anding learned.

There is no need to learn lessons the hard uninformed has been well known for 20-30 has been well known for 20-30 has been well known for 20-30 years sht been forsitting 20-30in the height of of the the room room we we were were sitting sitting in inyears - way. at about about 5.5m5.5mthe height -years at ht of ofthe the thewell room roomknown we wewere were were sitting sitting in inyears at atabout about about 5.5m5.5mt of room we ---at 5.5mSpace Associatio Ms will Ms will Ms will Dosoft the eyes research, seek out old timers who have that precious for reinforcing the softall eyes for TBMstanding for reinforcing soft eyes for TBM for reinforcing the soft eyes for TBM reinforcing the forwhen TBM 6mthe floor to ceiling astonishing size when in 6m floor to ceiling –– the astonishing size when The merits merits of of using using polyfibre polyfibre for for concrete concrete rein rein to to ceiling ceiling ceiling ––– astonishing astonishing astonishing size size when when standing standing in in to size standing in The The Themerits merits merits of ofusing using usingpolyfibre polyfibre polyfibre for forstanding concrete concretein reinforcement reinforcement The of for concrete reinforcement either either either break-outs and break-ins break-ins and in his knowledge andsegmentally experience, go back to school to know what is his the break-outs and in break-outs and break-ins and in his ak-outs and TBM break-ins in his front front of an assembled TBM onthe inand the segmentally lined of an assembled TBM on in the segmentally lined • ITACETby – ITA Co were detailed in in the the presentation presentation by Fibrec an an assembled assembled TBM TBMon on onin in inand the the segmentally segmentally lined lined n assembled the lined were detailed Fibrecr were were detailed detailed in in the the presentation presentation by by Fibrecrete Fibrecrete while while were detailed in presentation by Fibrecrete while ducing Pierre ducing ducing presentation Pierre Hoffman introduce Pierre Hoffman introduce and greatest in technologies attend conferences and presentation Pierre Hoffman introduce sentation Hoffman introduce tunnelpresentation hasavailable, excavated. tunnel itit has excavated. the high qualities of of micro micro steel steel fibre, fibre, aa brass brass co co has has excavated. excavated.latest has excavated. the qualities the the qualities qualities of of micro micro steel steel fibre, fibre, a a brass brass coated coated high high the qualities of micro steel fibre, a brass coated nd CO2 dd CO2 CO2 the the growing applicationand of GFRP GFRP as as the growing of •hasLegacy of under the growing application of GFRP as network with othersas facing exactly same application challenges problems, growing application of GFRP carbon-steel fibre which which has increased tensil carbon-steel fibre increased tensile carbon-steel carbon-steel fibre fibre which which has has increased increased tensile tensile strength strength carbon-steel fibre which has increased tensile strength across across across permanent reinforcement elements permanent reinforcement elements permanent reinforcement elements use the technical libraries, engage with research laboratories, manent Terratec confirmed on its stand that that it has hasout the order to toand Terratec on its stand itseek the order and crack crack resistance resistance properties, properties, produced and confirmed confirmed reinforcement on on its its its stand stand stand that thatelements has has the the order order order to to confirmed and produced and confirmed on that ititit has the to and and crack crack resistance resistance properties, properties, produced produced and andsupplied supplied supplied and crack resistance properties, produced • A leap forward t bs and in fibrethe sticularly s and and particularly in fibrenew reinforced segmental particularly in fibre reinforced segmental particularly in fibre reinforced segmental segmental advice of experts on manufacture everything, from trying forms of contract manufacture and supply the two 14.2m diameter TBMs and supply the two 14.2m diameter TBMs byof Precision Drawell was was promoted promoted as as the the fib fi ture ure and and and supply supply supplyreinforced the the two two 14.2m 14.2m 14.2m diameter diameter TBMs TBMs by Precision Drawell ure the two diameter TBMs by by Precision Precision Drawell Drawell was was promoted promoted as as the the fibre fibre of of the the by Precision Drawell was promoted as the fibre the kforce. kforce. kforce. linings were extra rebar strength is TunnelTalk Editor Shani Wallis linings were extra rebar strength is TunnelTalk Editor Shani Wallis linings were extra rebar strength is TunnelTalk Editor Shani Wallis ngs were extra rebar strength is to developing a new mix for concrete.

It is all there in the annuls and in required by by the the Kumar/NCC JV for for the the GMLR GMLR GoregaonGoregaonrequired JJ Kumar/NCC JV future. n n by bythe the theJJJKumar/NCC Kumar/NCC Kumar/NCCJV JV JVfor for forthe the theGMLR GMLR GMLRGoregaonGoregaonGoregaonfuture. by future. future. n n future. n of the thefor (right) of of the required for hybrid applications. applications.

GFRP (right) meets withProfessor Professor Iyer required for hybrid GFRP meets with Iyer required for hybrid applications.

GFRP (right) meets with Professor Iyer uired hybrid applications.

GFRP the experience of your mentors and educators.

Mulund linkroad road toconnect connect Mumbai’swestern western andeastern eastern Mulund link to Mumbai’s and nk nk road road to toconnect connect connect Mumbai’s Mumbai’s western western and and eastern eastern nk road to Mumbai’s western and eastern Ms from 60-70% less CO in its ss from from in its its generates 60-70% 60-70% less less CO CO222 in generates in its generates 60-70% less CO nerates 2 lly upto to18-19m 18-19m diameter, y up diameter, ly up to 18-19m diameter, production comparedto tosteel steel rebar and the reduction production rebar and the reduction is production compared to steel rebar and the reduction isis d to steel rebar and the reduction is compared References References References References References fthe the session, reminded the session, reminded more whenthe theamount amountof ofmaterial materialcan canbe bereduced reducedin inthe the more when more when the amount of material can be reduced in the unt ofsession, materialreminded can be reduced in the ITA -- International International Tunnelling Tunnelling and and Unde Unde wmore morethan thanthree threetimes times •• ITA more than three times designwith withGFRP. GFRP. ITA ITA---International International InternationalTunnelling Tunnelling Tunnellingand and andUnderground Underground Underground ••• ITA design design with GFRP. TunnelTalk Rescue of the 41 Association workers who spent 17 days and sitting in---at atabout about 5.5m- is publishing a series of Case tting in 5.5mitting in at about 5.5mSpace Association Space Space Space Association Association Association Study Special Editions to bring more thanSpace 40 trapped ahead of a 60m long collapse just 200m i gpolyfibre sizewhen when standing in size in size when standing in Themerits meritsof ofusing usingpolyfibre polyfibrefor forconcrete concretereinforcement reinforcement The The merits of using polyfibre for concrete reinforcement forstanding concrete reinforcement years of reporting in the industry by its Editor ITACET ITA Committee for Education •• Training ITACET –– ITA Committee Education 2.5kmand portal heading of the 4km longfor Silkyara road the segmentally lined • • ITACET ITACET – – ITA ITA Committee Committee for for Education Education and and Training Training • ITACET – ITA Committee for Education nnenthe segmentally lined the segmentally lined were detailed in the presentation by Fibrecrete while were detailed were detailed in in the the presentation presentation by

by Fibrecrete Fibrecrete while while presentation by Fibrecrete while Shani Wallis to focus.

Access these for early excavation, is nominated as the top event of 20 thehigh qualities of of micro micro steel steel fibre, fibre, aaa brass brass coated coated high high the qualities the qualities of micro steel fibre, brass coated high ro steel fibre, a brass coated Legacy of underground underground infrastructure •• the Legacy of infrastructure Legacy Legacy of ofunderground underground underground infrastructure infrastructure •••hasLegacy of infrastructure UK, USA, Denmark, Canadafibre and India projects the joy at ultimate safe return of the workers carbon-steel which increased tensile strength strength fibre has tensile carbon-steel fibre which which has increased increased tensile strength hich has increased tensile carbon-steel strength and on ground freezing technology on the families, as well as for the critical lessons to be learn that it has the order to hat it has the order to that it has the order to and crack resistance properties, produced and supplied and produced and and crack crack resistance resistance properties, properties, produced and supplied A leap leap forward forward to to SRFC SRFC segmental segmental linin e properties, produced and supplied linin Aleap leap leap forward forward to tosupplied SRFC SRFCsegmental segmental segmentallinings linings linings•• A ••• with AA forward to SRFC TunnelTalk digital magazine platform 14.2mpromoted diameter TBMs diameter TBMs ooll 14.2m 14.2m diameter TBMs byofPrecision Precision Drawell was promoted promoted as as the the fibre fibre of of the the by Drawell was by Precision Drawell was promoted as the fibre of the was as the fibre the SPECIAL EDITION SPECIAL EDITION SPECIAL EDITION SPECIAL others to follow. for theGMLR GMLRGoregaonGoregaonFOCUS: DENMARK CASE STUDIES or or the the GMLR GoregaonAccording to reportsFOCUS: - and kudos to the local new FOCUS: UK CASE STUDIES USA CASE STUDIES FOCUS: CANADA future. n n future. future. n bai’s westernand andeastern eastern ai’s ai’s western western and eastern and television media who were on the spot reportin move and update and providing the feed to take th References References References viral and more kudos to the professionals on the sp AMR water supply drive were providing detailed explanations of what was oc ITA---International InternationalTunnelling Tunnellingand andUnderground Underground ••• ITA ITA International Tunnelling and Underground onal Tunnelling and Underground to the media - there is much to be investigated in a f SpaceAssociation Association Space Space Association ation fashion to know all the exact details of how and w collapse happened.Rockfalls, rescues, recoveries • ITACET – ITA Committee for Education and Training •• Training ITACET ITACET –– ITA ITA Committee Committee for for Education Education and and Training Training Committee for Education and

ng ng cement cementfrom from fromthe the themix. mix. mix. g cement

2. Knowing where we’ve come from to influence the future

From TunnelTalk

1. Top event - the Novemb

Direct by Design

Direct by Design

Direct by Design

Direct by Design Direct by Design Direct Direct by by Design Design Direct by Design

Directby byDesign Design Direct

Direct by Design

Direct by Design

Direct Direct by by Design Design Direct by Design

Direct by Design Direct by Design Direct Direct by by Design Design Direct by Design

Direct Direct by by Design Design Direct by Design

Direct by Design Direct by Design Direct Direct by by Design Design Direct by Design

41 workers were trapped for 17 days and nights behind a 50m rockfall some 250m from the excavation portal of the Silkyara road tunnel portal in northern India until rescued on 28 November

Direct by Design

An epic tale of long distance TBM excavation

Underground in Action U

DISCUSSION FORUM

Shani Wallis, TunnelTalk

erground infrastructure

A

s the situation at the Silkyara road excavation project in northern India was unfolding, professionals of the underground construction industry were gathered in Mumbai for the Tunnelling Asia Conference and the 9th Edition of the ITA Tunnelling Awards. Everyone was keeping up to date with progress at Silkyara, particularly via the media reports by Arnold Dix who was expected to officiate at the Mumbai event as the current President of the ITA, International Tunnelling and Underground Space Association, but was instead on site in Uttarakhand offering support, expertise and advice in his private professional consulting capacity to the rescue efforts of the 41 tunnellers

Legacyof ofunderground undergroundinfrastructure infrastructure ••• Legacy Legacy of underground infrastructure

leapforward forwardto toSRFC SRFCsegmental segmentallinings linings AAleap leap forward to SRFC segmental linings d to SRFC segmental linings••• A

CIAL CIAL EDITION EDITION AL EDITION UK CASE CASESTUDIES STUDIES STUDIES KKCASE

SPECIAL EDITION SPECIAL EDITION SPECIAL SPECIALEDITION EDITION EDITION SPECIAL FOCUS: UKCASE CASE STUDIES FOCUS: UK CASE STUDIES FOCUS: FOCUS: USA USA CASE CASESTUDIES STUDIES STUDIES FOCUS: USA

SPECIAL SPECIALEDITION EDITION EDITION SPECIAL FOCUS: FOCUS:DENMARK DENMARK DENMARKCASE CASE CASESTUDIES STUDIES STUDIES FOCUS:

SPECIALEDITION EDITION SPECIAL SPECIAL SPECIALEDITION EDITION EDITION SPECIAL FOCUS:DENMARK DENMARKCASE CASESTUDIES STUDIES FOCUS: FOCUS: FOCUS:CANADA CANADA CANADACASE CASE CASESTUDIES STUDIES STUDIES FOCUS:

1

Directby byDesign Design Direct

Direct by Design Direct Direct by by Design Design Direct by Design Direct by Design

er er supply supplydrive drive drive r supply

workers were trapped 41 41 workers were trapped forfor days and nights behind 17 17 days and nights behind a 50m rockfall some 250m a 50m rockfall some 250m

Direct Directby byDesign Design

Direct by Design Direct by Design Direct by Design Direct by Design Directby byDesign Design Direct

41 41 workers workers were were trapped trapped 41 workers were trapped for forfor 17 17 days days and nights nights behind behind 17 days andand nights behind a 50m a rockfall 50m rockfall rockfall some some 250m 250m a 50m some 250m from from the the excavation excavation portal portal from the excavation portal of of the the Silkyara Silkyara road road tunnel tunnel of the Silkyara road tunnel portal portal in in northern northern India India until until portal in northern India until rescued rescued 28 28 November November rescued on on 28on November

Direct Design Direct by Design Direct byby Design Direct Direct by by Design Design Direct by Design

Direct Design Direct Design by Design Direct byby Design

Direct Design Direct by Design Direct byby Design

AMRwater watersupply supplydrive drive AMR

UndergroundininAction Action UU Underground

Underground U Underground U inAction Action Underground U ininAction

Rockfalls, Rockfalls,rescues, rescues, rescues,recoveries recoveries recoveries Rockfalls,

AAA

Underground Underground U inAction Action UU Underground ininAction

s the situation at the Silkyara road excavation project s the situation at the Silkyara road excavation project in northern India was unfolding, professionals in northern India was unfolding, professionals of of thethe underground construction industry were gathered underground construction industry were gathered Mumbai Tunnelling Asia Conference and in in Mumbai forfor thethe Tunnelling Asia Conference and thethe Edition Tunnelling Awards.

Everyone was 9th9th Edition of of thethe ITAITA Tunnelling Awards.

Everyone was keeping date with progress Silkyara, particularly keeping upup to to date with progress at at Silkyara, particularly media reports Arnold who was expected viavia thethe media reports byby Arnold DixDix who was expected to to officiate Mumbai event current President officiate at at thethe Mumbai event as as thethe current President of of the ITA, International Tunnelling and Underground Space the ITA, International Tunnelling and Underground Space Association, was instead in Uttarakhand offering Association, butbut was instead onon sitesite in Uttarakhand offering support, expertise and advice private professional support, expertise and advice in in hishis private professional consulting capacity to the rescue efforts of the tunnellers consulting capacity to the rescue efforts of the 41 41 tunnellers

1

Follohe Follo LL Follo Follo Line Line Follo beenLine 21 similar but smaller collapses in the portal highspee spee high

FOCUS: GROUND FREEZING FOCUS: GROUND FREEZING FOCUS: INDIA CASE STUDIES Boston Boston Big Big Dig Dig Project Project FOCUS: INDIA CASE STUDIES Boston Big Dig Project FOCUS: INDIA CASE STUDIES 1

41 workers were trapped 41 41 workers were trapped forfor for workers were trapped 17 and daysnights and nights behind 17 17 days behind days and nights behind a 50m rockfall some 250m

Direct Design Direct by Design Direct byby Design

1 1

of of thethe Silkyara road tunnel Silkyara road tunnel portal in northern India until

Norway Norway Norway

portal in in northern India until portal northern India until December 2022 rescued on 28 November rescued onon 2828 November rescued November

December 2022 December 2022 December 2022

DISCUSSION FORUM DISCUSSION FORUM DISCUSSION FORUM

Underground in Action U

Rockfalls,rescues, rescues,recoveries recoveries Rockfalls, Rockfalls, rescues, recoveries Shani Wallis, TunnelTalk Shani Wallis, TunnelTalk Shani Wallis, TunnelTalk

AAA

Underground U inAction Action UU Underground ininAction Underground

Grand Opening

ionEDITION Case Study CIAL EDITION AL IAL EDITION ROUND FREEZING OUND ROUND FREEZING g DigFREEZING Project

4

1

Underground U inAction Action UU Underground ininAction Underground

Underground U in Action November November 2023 2023 November 2023

s the situation at the Silkyara road excavation projectheld held on the far side ofrockfall the rockfall that blocked portal s the situation at at thethe Silkyara road excavation project on the far side of thethe that blocked portal s the situation Silkyara road excavation project held on the far side of rockfall that blocked portal in northern India was unfolding, professionals of theaccess access to the 2.5km heading of the road tunnel excavation. in in northern India was unfolding, professionals of of thethe to to thethe 2.5km heading of of thethe road tunnel excavation. northern India was unfolding, professionals access 2.5km heading road tunnel excavation. underground construction industry were gathered underground construction industry were gathered underground construction industry were gathered in Mumbai for the Tunnelling Asia Conference and With reports coming through, there was much discussion in inMumbai forforthe Asia and reports coming through, there was much discussion Mumbai theTunnelling Tunnelling AsiaConference Conference andthe the theWith With reports coming through, there was much discussion 9th Edition ofITA the ITA Tunnelling Awards.

Everyone atconference the conference about what might have happened 9th9th Edition of of thethe Tunnelling Awards.

Everyone was thethe about what might have happened to to to Edition ITA Tunnelling Awards.

Everyone waswasat at conference about what might have happened keeping up to with date with progress at Silkyara, particularlyhave caused have caused the rockfall from the crown of the excavation keeping upup to to date progress at at Silkyara, particularly thethe rockfall from the crown of of thethe excavation keeping date with progress Silkyara, particularly have caused rockfall from the crown excavation the media reports

by Arnold Dix who was expected some 250m from the portal and 2,100m back from viavia thevia media reports byby Arnold DixDix who was expected to to tosome 250m from the portal and 2,100m back from the the media reports Arnold who was expected some 250m from the portal and 2,100m back from the the officiate atMumbai the Mumbai event ascurrent the current President advancing face of4.5km the 4.5km long tunnel.

The collapsed officiate at at thethe event asas thethe President of of ofadvancing face of thethe long tunnel.

The collapsed officiate Mumbai event current President advancing face of 4.5km long tunnel.

The collapsed the ITA, International Tunnelling and Underground Space section of the heading will have been standing in its thethe ITA, International Tunnelling and Underground Space section of the heading will have been standing in its ITA, International Tunnelling and Underground Space section of the heading will have been standing in its Association, but was instead on in Uttarakhand offeringprimary-lined primary-lined state of shotcrete and lattice girders, Association, butbut was instead onon site insite Uttarakhand offering state of of shotcrete and lattice girders, forfor for Association, was instead site in Uttarakhand offering primary-lined state shotcrete and lattice girders, support, expertise and advice inprivate his private professionalmany many months but, according to on-site reports, there support, expertise and advice in in hishis professional months but, according to to on-site reports, there was support, expertise and advice private professional many months but, according on-site reports, there waswas consulting capacity to the rescue efforts of 41 tunnellersno indication, no indication, immediate or historic, that the tunnel at that consulting capacity to to thethe rescue efforts of of thethe 41the tunnellers immediate or or historic, that the tunnel at at that consulting capacity rescue efforts 41 tunnellers no indication, immediate historic, that the tunnel that

Follo Line

GrandOpening Opening Grand Grand Opening

FolloLine Line Follo Follo Line

NATM excavation NATM excavation NATM excavation was progressing was progressing was progressing under anform EPC form under anan EPC under EPC form of contract of of contract contract

high speed railway line

highspeed speedrailway railwayline line high high speed railway line

SpecialEdition EditionCase CaseStudy Study Special Special Edition Case Study 11 1

1

BostonBig BigDig DigProject Project Boston Boston Big Dig Project 1 1

1

1 1

Special Edition Case Study towards the in-tunnel breakthrough.

This is unsurprisin Boston BigDig DigProject Project Boston Big past experience in the foothills of the Himalayas for hy earlier road and rail links. Geological conditions encou on the Rohtang road tunnel, which is not too dista Silkyara between the States of Himachal Pradesh and and Kashmir, tested NATM excavation to the extrem several collapses and inrushes of water and gouge b was successful completed and opened to traffic in O 2020 – without any accidents or serious situations crews. TBM headings for the Kishanganga, Tapov other hydro projects in the region have all experience geological conditions that have required bypass he and excavations out over or around the TBM shield blocked cutterheads and prepare the way for further ad 1

Direct Design Direct by Design Direct byby Design

50m rockfall some 250m a 50m rockfall some 250m from the excavation portal Direct byafrom Design the excavation portal from the excavation portal of the Silkyara road tunnel

Norway

Special Edition Case Study

high highspeed speed speedrailway railway railwayline line line high

SPECIAL EDITION Special Special Edition Edition Case CaseStudy Study Study Special Edition Case SPECIAL EDITION SPECIAL EDITION SPECIAL EDITION SPECIAL EDITION 1 1 1 1 1

Direct Design Direct by Design Direct byby Design Direct by Design

Direct by Design Direct by Design Direct by Design

With reports coming through, there was much discussion With reports coming through, there was much discussion conference about what might have happened at at thethe conference about what might have happened to to have caused rockfall from crown excavation have caused thethe rockfall from thethe crown of of thethe excavation some 250m from portal and 2,100m back from some 250m from thethe portal and 2,100m back from thethe advancing face 4.5km long tunnel.

The collapsed advancing face of of thethe 4.5km long tunnel.

The collapsed section heading have been standing section of of thethe heading willwill have been standing in in its its primary-lined state shotcrete and lattice girders, primary-lined state of of shotcrete and lattice girders, forfor many months but, according on-site reports, there was many months but, according to to on-site reports, there was indication, immediate historic, that tunnel that nono indication, immediate or or historic, that thethe tunnel at at that

NATM excavation NATM excavation was progressing was progressing under EPC form under anan EPC form contract of of contract

SPECIAL EDITION SPECIAL EDITION SPECIAL EDITION FOCUS: CANADA CASE STUDIES FOCUS: CANADA CASE STUDIES FOCUS: CANADA CASE STUDIES

1 1

held side rockfall that blocked portal held onon thethe farfar side of of thethe rockfall that blocked portal access 2.5km heading of the road tunnel excavation. access to to thethe 2.5km heading of the road tunnel excavation.

GrandOpenin Openin Grand Grand GrandOpening Opening Opening Grand According to reports after the happy day of rescue, th

NATM NATM excavation excavation NATM excavation

was progressing progressing waswas progressing under under an EPC EPC form form under an an EPC form of of contract contract of contract

SPECIAL EDITION SPECIAL EDITION SPECIAL SPECIAL EDITION EDITION SPECIAL EDITION SPECIAL EDITION SPECIAL EDITION FOCUS:INDIA USACASE CASE STUDIES FOCUS: USA STUDIES FOCUS: FOCUS: GROUND GROUND FREEZING FREEZING FOCUS: USA CASE STUDIES FOCUS: FOCUS: GROUND CASEFREEZING STUDIES

UndergroundininAction Action UU Underground

Underground Underground U in inAction Action UU Underground in Action November 2023 November 2023

Shani Wallis, TunnelTalk Shani Wallis, TunnelTalk

November November 2023 2023 November 2023

s the s the situation situation at the at the Silkyara Silkyara road road excavation excavation project projectheld held held on the the far far side side of the the rockfall rockfall that blocked blocked portal portal s the situation at the Silkyara road excavation project on on the far side of theof rockfall thatthat blocked portal in northern in northern India India was was unfolding, unfolding, professionals professionals of of thetheaccess access access to to the the 2.5km 2.5km heading heading of of the the road road tunnel tunnel excavation. excavation. in northern India was unfolding, professionals of the to the 2.5km heading of the road tunnel excavation. underground underground construction construction industry industry were were gathered gathered underground construction industry were gathered in in Mumbai Mumbai for the the Tunnelling Tunnelling Asia Asia Conference Conference and thetheWith With With reports reports coming coming through, through, there there was much much discussion discussion in Mumbai for for the Tunnelling Asia Conference andand the reports coming through, there waswas much discussion 9th Edition Edition of of the the ITA ITA Tunnelling Tunnelling Awards.

Awards.

Everyone Everyone wasat the at at the the conference conference about about what what might might have have happened happened 9th9th Edition of the ITA Tunnelling Awards.

Everyone waswas conference about what might have happened to to to keeping keeping to to date date with with progress progress at at Silkyara, Silkyara, particularly particularlyhave have have caused caused the rockfall rockfall from from the the crown crown of of the the excavation excavation keeping up up toup date with progress at Silkyara, particularly caused thethe rockfall from the crown of the excavation via the the media media reports reports by Arnold Arnold Dix who who was was expected expected some some 250m 250m from from the portal portal and 2,100m 2,100m back back from from via via the media reports by by Arnold DixDix who was expected to to tosome 250m from thethe portal andand 2,100m back from thethethe officiate officiate at at the the Mumbai Mumbai event event the the current current President President advancing advancing face face of of the the 4.5km 4.5km long long tunnel. tunnel.

The collapsed collapsed officiate at the Mumbai event as as theas current President of of ofadvancing face of the 4.5km long tunnel.

TheThe collapsed the ITA, ITA, International International Tunnelling Tunnelling and Underground Underground Space Spacesection section section the the heading heading will have have been been standing standing in in its its thethe ITA, International Tunnelling andand Underground Space of of theof heading willwill have been standing in its Association, Association, but was was instead instead site in Uttarakhand in Uttarakhand offering offeringprimary-lined primary-lined primary-lined state state of shotcrete shotcrete and lattice lattice girders, girders, Association, butbut was instead on on siteon insite Uttarakhand offering state of of shotcrete andand lattice girders, for forfor support, support, expertise expertise and advice advice in in his his private private professional professionalmany many many months months but, according according to to on-site on-site reports, reports, there there was support, expertise andand advice in his private professional months but,but, according to on-site reports, there waswas consulting consulting capacity capacity to to the the rescue rescue efforts efforts of of the 41 41 tunnellers tunnellersno no no indication, indication, immediate immediate or or historic, historic, that the the tunnel tunnel at at that that consulting capacity to the rescue efforts of the 41the tunnellers indication, immediate or historic, thatthat the tunnel at that

CIALEDITION EDITION IAL CIAL EDITION AL EDITION NMARK CASE STUDIES MARK CASE STUDIES MARK CASE STUDIES ADA CASE STUDIES

Norway Norway

portal in northern India until portal in northern India until

December December 2022 rescued on November December 2022 rescued on2022 2828 November

DISCUSSIONFORUM FORUM DISCUSSION

DISCUSSION DISCUSSION FORUM FORUM DISCUSSION FORUM

Shani Shani Wallis, Wallis, TunnelTalk TunnelTalk Shani Wallis, TunnelTalk

Directby byDesign Design Direct

from excavation portal from thethe excavation portal Direct Direct by by Design Design Direct by Design Silkyara road tunnel of of thethe Silkyara road tunnel

Norway Norway Norway

Anepic epictale taleofoflong longdistance distanceTBM TBMexcavation excavation An

ng gdistance distance distance TBM TBM excavation excavation TBM excavation

Recognition is afforded to all involved in the rescue e Silkyara although it all contributed to the general m media, experts, politicians, extra construction crews SPECIAL EDITION EDITION SpecialSPECIAL Edition SPECIALEDITION EDITION SPECIAL SPECIAL SPECIAL E SPECIAL EDITION SPECIAL SPECIALEDITION EDITION EDITION SPECIAL FOCUS: USA CASE CASEFREEZING STUDIES members and the curious, mixed with movement of ve FOCUS:CANADA CANADA CASESTUDIES STUDIES FOCUS: USA STUDIES FOCUS: CASE FOCUS:INDIA INDIA FOCUS: C FOCUS: GROUND Boston Big D FOCUS: FOCUS:INDIA INDIA INDIACASE CASE CASESTUDIES STUDIES STUDIES FOCUS: trucks and heavy construction equipment overload small hillside jobsite. As for the story going viral, the little option in this age of instant social media broadc the world. There is nowhere to hide for project mana job sites, no coverup of any incident, and only seco get out in front with the official story, ahead of the un unauthorised Rockfalls, rescues,recoveries recoveries sensational social media posts, the ma Rockfalls, rescues, themselves likely hearing of the incident via those po AA With reports coming through, there was much discussion at the conference about what might have happened to have caused the rockfall from the crown of the excavation some 250m from the portal and 2,100m back from the advancing face of the 4.5km long tunnel. The collapsed section of the heading will have been standing in its primary-lined state of shotcrete and lattice girders, for many months but, according to on-site reports, there was no indication, immediate or historic, that the tunnel at that

NATM excavation was progressing under an EPC form of contract

1

Direct Direct by Design Design Direct byby Design

November 2023

held on the far side of the rockfall that blocked portal access to the 2.5km heading of the road tunnel excavation.

1

1 1 1 1

1 1

ber 2023 tunnelling crew rescue in India

d nights into the d tunnel 023 for to their ned.

wspaper g every he story pot who ccurring forensic why the

effort at malae of s, family ehicles, ding the ere was casts to agers on onds to nofficial, anagers osts.

here had eadings ng given ydro and untered ant from Jammu me with before it October for the van and ed tough eadings to clear dvance.

The collapse that trapped 41 workers in the Silkyara road tunnel heading in November was avoidable

Two rescued workers looking physically well but evidently dazed by the ordeal and its overwhelming attention (Photos by TOI and PTI)

Further reporting by The Times of India, quotes officials that the contractor is to shoulder the full cost of the rescue.

Perhaps unreasonable considering it was evident the contractor was not in control of all the rescue developments or their costs. The Indian military services were called in to assist with the rescue, as were many different experts and independent companies, with heavy drilling equipment flown in or trucked up to expedite the rescue. To have to pay would be okay if the contract stipulates that the contractor provides an open cheque book to manage any disaster and the EPC, engineering, procurement and construction, form of contract, commonly used in India and applied for the Silkyara project, is not known for its risk sharing mechanisms and in fact is preferred because it passes all risk to the contractor.

For the industry however, the situation on the Silkyara project, even in the foothills of the Himalayas in India, was avoidable. And it was! So why did it happen? Simple. No one ever learns of the mistakes of others.

Further reporting by The Times of India states that a preliminary report by a panel of experts identifies that the engaged contractor is well experienced in off-shore marine engineering but has little to no experience of tunnel excavation, least of all with NATM and in the difficult geology of the Himalayas. It finds inadequate deployment of sensors and instruments to capture the ground behaviour during reprofiling work that was underway in the same area as when and where the collapse occurred. The panel of experts also suggest that reprofiling indicates inadequate initial support and the need for stricter supervision and monitoring of the work by the client organisation. As a result, the suggestion for going forward is to establish a centre for road and rail excavations to develop a new standard operating procedure for tunnel safety and a “geological collaborative framework for better planning and execution of projects, particularly in the Himalayan region.

Nothing new here. Nothing here that hasn’t been the outcome of previous collapses, let us hope that this centre doesn’t invent another new acronym for the excavation process known as NATM (or SCL or SEM or TOM the observational tunnelling method or any other assigned title) and that it begins by bringing together all the existing

reports, articles, forensic studies, and written testimony of those involved with previous collapses and management of difficult geological conditions on NATM projects, including Rohtang, and of perhaps the most famous, or infamous NATM tunnel downfall, the Heathrow Express Rail Link project in London in 1994. A criminal court case into the Heathrow incident also found fault with the form of contract, which permitted self-certification by the designbuild contractor; lack of authority to supervise and monitor the works by the owner’s organisation; lack of adequate experience in the contractor’s team of the processes and importance of procedures in managing NATM excavation and repair of defects successfully; inadequate installation and, faulty instrumentation and disregard of what the instruments were warning of.

A full report of the collapse and its recovery is reported in the TunnelTalk UK Special Edition Case Studies publication. The expert panel that investigated the incident changed the name of NATM to SCL, sprayed concrete lining method, and changed the design of the concept to a prescribed approach that removes the ability to be flexible on site to adapt the support and excavation cycles to conditions as actually experienced and encountered on the jobsite. Not wanting to adopt the UK redesign, the USA renamed the concept to SEM, the sequential excavation method, slight differences but also basically NATM. Two final thoughts for the number one top event of 2023 to influence the future. One, we must be aware of previous mistakes and disasters to learn from them. The technical trade media have a duty to keep reporting on these topics.

And two, the underground construction industry must get over itself and agree to open and thorough forensic investigation of its excavation failures and disasters, just as the bridge building or the aviation or the medical profession or the aerospace industry does, by law. Being embarrassed by mistkaes or serious incidents or trying to cover them up or forget them just won’t do. A start on this very openness of investigation for the advance of the industry was the response by the contractor and the client into the MSV vehicle fire on the High Speed 2 TBM rail tunnel project in the UK where reports to the British Tunnelling Society have made it clear what happened and how similar incidents can be avoided in the future. Moving the industry forward is the objective of everyone involved – or should be. n