Prefabricados y Sismos

PRECAST AND SEISMICITY

EXPERIENCES WITH PRECASTING

PRECAST TODAY IN FINLAND Current share of precast in building frames: • • • •

74% in Multi-storey residential buildings 74 % in Office buildings 46 % in Storage buildings 35% in Industrial buildings

ANNUAL HOLLOW-CORE PRODUCTION PER CAPITA Finland Norway Denmark Belgium

0,08 0,06 0,05 0,05 0,033 0,01 0,008

Ireland France Germany

0

0,14 0,14 0,125

0,2

0,21

0,36

0,4

0,6

0,6

WHY PRECAST?

WHY INDUSTRIALIZED CONSTRUCTION? • High demand for housing • Cost pressure, need for affordable housing in cities • Low productivity on traditional building sites • Construction time pressure in projects • Need for better construction quality • Higher demands for safety at job sites • Increased need for sustainability, environmentally friendly ways of working and decreased amount of waste in all project phases

BENEFITS OF PREFABRICATION BETTER QUALITY OF CONSTRUCTION BETTER PRODUCTIVITY (FACTORY AND SITE) SPEED OF CONSTRUCTION MORE EFFICIENT DESIGN SAVINGS IN BUILDING AND LIFETIME COSTS

MANUFACTURING VS CONSTRUCTION Current construction

Value added Support activity Waste

Source: Construction Industry Institute 2004

Current manufacturing

Value added Support activity Waste

Typical waste sources at construction sites:

• • • • • •

material waste extra handling and movements over-dimensioning waiting mistakes storage

PRECAST PRODUCTS

THE MOST COMMON PRECAST PRODUCTS •

Façades from sandwich to cladding and grey walls • Floors with hollow-core, half, ribbed or solid slabs • Partition and internal walls from Acotec panels to solid walls • Foundations with precast concrete piles SAVINGS IN BUILDING LIFETIME • Frames such as beams, AND columns, slabs COSTS • Balconies and stairs

HOLLOW-CORE SLABS • Hollow-core slabs are pre-stressed floor

products with either round or shaped voids, depending on local conditions.

• Less raw material is needed to achieve the same load bearing capacity as cast in-situ structures.

• Hollow-core slabs allow long spans which

translates into less load-bearing walls and therefore cost savings and more efficient use of space.

SANDWICH PANELS • • • •

Sandwich panel is a dominating facade type in prefabricated concrete buildings The panel consists of two layers of concrete and a layer of rigid insulation between them Controlled thermal insulation ensures energyefficiency and big savings in the building’s operational costs Enables high variation of surfaces such as exposed aggregate, clinker, acid treaded, colored concrete and more.

PARTITION WALL PANELS ACOTEC • Non-load bearing partition wall panels are ideal for places where excellent sound insulation and moisture-resistance are key.

• Building work proceeds up to 6 times faster when compared with traditional brickwork and even 2 times faster than blockwork.

• The panels have exact dimensions and completely flat surface meaning that no plastering is needed.

• Thin structure leaves more floor space.

COST-EFFICIENCY AND EFFICIENT DESIGN

KEY TO EFFICIENT CONSTRUCTION IS WELL-THOUGHT-OUT DESIGN • • • • • • • •

Perimeter of the house compared to the area of apartments Number of corners Number of apartments per staircase and its area Height of the building Usage area / total area Number of loadbearing walls Thickness of partition walls Diverse floor plans for different levels

WHY IS DESIGN IMPORTANT? Cost 100%

Designing

Construction

Cost cumulation Cost determination

Project time

EFFICIENT PRECAST DESIGN

SMART PRECAST FRAME SYSTEM?

CHOICE OF FRAME SYSTEM Beams-and-Columns and Short Solid Slabs

Beams-and-Columns and Long Span Floors

Load-bearing Walls and Long Span Floors

NOTE! Number of pieces, complexity and amount of needed site work

COMPETITIVENESS OF PREFABRICATION Saving material • 20 – 30 % less steel • 20 – 30 % less cement and/or concrete

Saving Time •

2-3 times faster

PRECAST IS A COMPETITIVE CHOICE Savings in steel AMOUNT OF TOTAL REINFORCEMENT depending on span and floor type

25

HCS reinf.

Half Slab reinf.

Reinforcement [kg/m^2]

20

Cast in Situ reinf.

Filigran reinf.

15

Loads: Self weight Dead load 0,5 kN/m^2 Live load 2,0 kN/m^2 Slab fields:

10

5

0

4

6

Span [m]

8

10

SEISMIC DESIGN OF PRECAST BUILDING

WORLD SEISMIC MAP

CASE STUDY IN CHINA: INDUSTRIALIZED CONSTRUCTION IN SEISMIC ZONES

CASE STUDY: BACKGROUND • Project utilized the highest construction know-how in Finland: • JKMM architects (www.jmkk.fi)

Multi-award winning architect office: more thanr 70 prizes with 35 first prizes in the past 10 years.

•

Finnmap Consulting Oy (www.fmcgroup.fi) A global leader specialized in precast design and structural design with BIM

•

Peikko (www.peikko.com) A specialist in concrete connections and composite beams for slim floors.

TARGET OF THE PROJECT To develop: A building system for industrially manufactured multi-storey apartment building

• • •

based on precast concrete building method based on Nordic (Scandinavian) experience modern Nordic industrialized building technologies (including building services, thermal insulation, ecology, fast assembly, quality, design etc.)

•

design according to Chinese needs and regulations (including seismic evaluation).

PROJECT PHASES • • • • • • • • • •

Local regulation Urban planning Floor layout design Architecture / Outlook Structural design Detailing Building services Sustainability Cost evaluation Checking of results by third party – –

Structural institute, Shanghai Holms Consulting, New Zeeland

STRUCTURAL SYSTEM:

PRECAST LARGE WALL PANEL / SHEAR WALL SYSTEM CODES AND STANDARDS USED:

• Nordic precast experience • Eurocode 8, Eurocode 2 • fib Commission 6 : Precast concrete buildings in • •

seismic areas: Practical aspects PCI: Seismic design of Precast / Prestressed Concrete Structures Chinese codes and standards

CALCULATIONS BASED ON Versions for PGA 0,05 g and PGA 0,20 g

Section

Description

Site location

China

Ground type

Hard to stiff clay

Occupancy

14-floors precast residential building

Building area

5,390 m²

Construction type

Precast concrete elements

Structural system

Shear wall system

Floor system

PC half slab + cast in situ concrete topping – diaphragm

Lateral system

Coupled wall system

Foundation system

Piled foundation

Design process system

Building Information Modeling (BIM), Interoperability of Tekla Structures, SCIA Engineering, RFEM Dlubal, AUTOCAD, and Excel

STRUCTURAL SYSTEM Cast-in-situ Vertical connection

Precast Solid Partition Wall 200 mm

Balcony Solid precast Wall 200 mmm Horizonatal wall connection

Sandwich Precast Wall Element Bearing shell 160 mm Insulation 100 mm Facade 70 mm

Balcony Soild Slab 220mm

CALCULATIONS Mode 1

Mode 2

0,769 sec [X-Dir.]

0,241 sec [X-Dir.]

< XDir>

0.2g Mode 1

Mode 2

1,069 sec [Y-Dir.]

0,560 sec [Y-Dir.]

< YDir >

0.05g Mode 1

Mode 2

Mode 1

Mode 2

0.403 sec [X-Dir.]

0.123 sec [X-Dir.]

0.441 sec [Y-Dir.]

0.300 sec [Y-Dir.]

< XDir>

< YDir >

SEISMICITY AND CONNECTIONS

SEISMICITY AND CONNECTIONS

SEISMICITY AND CONNECTIONS

CONCLUSION • Seismic loads and actions are big compared to • • •

non-seismic situations Seismic design is more demanding than standard structural design Seismic design expertise is often local Local codes follow often the principles of cast in situ

• Precast buildings can be used in seismic • •

conditions Shear wall system can be used in seismic areas The design of connections is the key point

CASE INDIA â&#x20AC;&#x201C; STUDENT HOUSE BY JINDAL

STRUCTURAL DETAILS Precast framing : Wall-frame system with solid concrete walls and prestressed slabs.

Foundation: Cast in situ strip foundation Imposed loads: • Corridors and stairs = 3.0 kN/m2 • Rooms = 2.0 kN/m2 • Balconies = 4.0 kN/m2 Seismic forces: • Zone IV - IS : 1893 -2002, • Zone Factor Z (Peak Ground Acceleration) = 0.24 • Soil Type – Medium Soil • Importance Factor = 1.00

ETABS FEM â&#x20AC;&#x201C; SH3 & 4

ETABS FEM â&#x20AC;&#x201C; SH3 & 4

ETABS ANALYSIS RESULTS

Wall Axial Stresses : Seismic in Y Direction

ETABS ANALYSIS RESULTS

Wall Axial Stresses : Seismic in X Direction

ELEMENT PRODUCTION DRAWING

ELEMENT PRODUCTION DRAWING

TYPICAL CONNECTION DETAILS

EXECUTION

EXECUTION

EXECUTION

EXECUTION

EXECUTION

EXECUTION

CASE INDIA: NAYA RAIPUR

NAYA RAIPUR, INDIA: 4,000 HOUSING UNITS Company BSBK got the project at the rate of 1450 Rs/sq ft.

The estimated structure + finishing cost will be 1150 Rs/sq ft (170â&#x201A;¬/sq. m)

NAYA RAIPUR, INDIA: 4,000 HOUSING UNITS • Cost includes • • • •

Solid concrete walls Painted walls and tile flooring Basic kitchen platform Piping/pluming/sanitary fixtures/tap/wash basin Conducting/wiring/switches/sockets

• • Optimizing layout would lower the construction cost

CASE UAE: ARABIAN RANCHES

FACTS IN BRIEF – ARABIAN RANCHES, UAE SCHEDULE

Production: • Need for 1041 villas (each 350 – 500m²) ⇒ 200 panels per day ⇒1 000m² hollow core slabs per day Working hours: • 1st shift 6:30-18:00 • 2nd shift 19:00-6:00 Meet modern standards: ISO 9001 certificate covering design, manufacturing and erection ⇒ Total workforce was 2000 persons of which 700 persons working in production ⇒ Production started in 2005 ⇒ Last villa handed over by the end of 2007

OTHER EXAMPLES

The Hills, South Africa

Photo: Anders Portman, Kuvatoimisto Kuvio Oy

Helsingin Viuhka apartments, Helsinki, Finland National Concrete Structure of the year 2016 Award Winner Untraditional balcony solution increases the functionality of the apartments and gives a distinctive outlook to the building

Flooranaukio apartments, Helsinki, Finland National Concrete Structure of the year 2011 Award Winner

Kangasala Highschool Kangasala, Finland Graphic concrete.

Solo Sokos Hotel Torni, Tampere, Finland Over 500 precast sandwich panels with a special black pigment.

Carlswarld, Midrand, Johannesburg, South Africa

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