Composites 20 + Polycon 09 01/15/2009

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1 Innovative Timber Composites: Improving wood with other materials 17 October 2013 Nicosia, Cyprus Use of CLT in Slovenia in seismically active areas Iztok Šušteršič Dr. Bruno Dujič CBD Contemporary Building Design d.o.o. Innovative Timber Composites: Improving wood with other materials 17 October 2013 Nicosia, Cyprus Content CLT and seismic Building design codes State of the art analysis procedures Seismic activity in Slovenia Case studies CBD Contemporary Building Design d.o.o. Who we are R&D performing SME Established in PhD, 4 M.Eng, 1 M. Arch, 1 B.Eng. What we do Building design (over 300 projects since 2006) Building execution of CLT structures (over 20 projects since 2006) Research and development (5 R&D projects since 2009) We are specialised in Seismic design of timber structures University of Weimar, Germany 1

2 CLT and seismic CLT structure GL = Glue-Lam XL = Cross-Lam (CLT) CLT and seismic CLT structure CLT and seismic General behaviour CLT 7 stories University of Weimar, Germany 2

3 CLT and seismic General behaviour CLT seismic response Rocking Slip + Friction Benefits Self-centering (minimal residual deformations) Low-cost no damage design CLT and seismic Multi-storey timber buildings storey SOFIE project, Ivalsa, IT storey SOFIE project, Ivalsa, IT storey STADHAUS, Waugh Thistleton Arch., GB storey POLARIS project, MAK Holz, IT CLT and seismic Multi-storey timber buildings 40 storey 30 storey 20 storey 12 storey University of Weimar, Germany 3

4 Building design codes Eurocodes Vertical loads; Self weight Live load Snow load Horizontal load; Wind Eurocode 1 Eurocode 5 Even though crosslam is not yet included in EC5, most of these load cases can be dealt with using the current standard (with some sensible interpretations) Building design codes Eurocodes Earthquake Eurocode 8 Eurocode 8 is in general heavily lacking guidelines for the seismic analysis of timber structures. Crosslam is of course no exception. Concrete Specific design rules in EC8 number of pages: Steel & Composite Masonry Timber 59 pg. 51 pg. 9 pg. 6 pg. State of the art procedures Linear modal response spectrum analysis 0,7 Periods 0,6 0,5 [s] 0,4 0,3 0,2 i ii iii (i) (ii) (iii) 0,1 i) Rigid ii) Elastic top and bottom, 0 iii) All elastic T1 T2 T3 no perpendicular Procedure Timber in global seismic analysis (always) modelled elastically (E, G) Connections linearised (substitute vertical stiffness of springs) University of Weimar, Germany 4

5 Slip [mm] Slip [mm] EXPERIMENT FEM 10 NAILS 1st CYCLE BACKBONE EXPERIMENT FEM 10 NAILS 3rd CYCLE BACKBONE ,00 0,01 0,02 0,03 0,04 0,05 0,06 0,07 0,08 0,09 Top floor displacement [m] 1) 1 ST. CYCLE, NO FRICTION 1f) 1 ST. CYCLE, FRICTION 2) 3 RD. CYCLE, NO FRICTION 2f) 3 RD. CYCLE, FRICTION 3) 3 RD. CYCLE, NO FRIC. NO GRAVITY 3f) 3 RD. CYCLE, FRICTION, NO GRAVITY Composites 20 + Polycon 09 01/15/2009 State of the art procedures Nonlinear static ( pushover ) analysis WALL B -EFFECT OF FRICTION Shear force [kn] Shear force [kn] Base shear [kn] Procedure Connection backbone response (1st / 3rd?) Pushover curve N2 method (procedure in EC8) State of the art procedures Nonlinear dynamic analysis 2 x BMF 105 shear x BMF 105 uplift , ,02 0,01 0,00-0,01-0, Slip [m] EXPERIMENT FEM SIMULATION FEM BACKBONE -0,03 Shear force [kn] Uplift force [kn] ,01 0,01 0,02 0, Displacement [m] EXPERIMENT FEM SIMULATION FEM BACKBONE Exact finite element modelling of connections in timber (cylic) Stiffnes degradation (cyclic) Strength degradatrion A pinching effect Slip Seismic activity in Slovenia Seismic activity in Europe Magnitude > 3 University of Weimar, Germany 5

6 Seismic activity in Slovenia 1895 Ljubljana Seismic activity in Slovenia 1998 Posočje Family housing 1 University of Weimar, Germany 6

7 Family housing 2 Family housing 3 Family housing 4 University of Weimar, Germany 7

8 CLt Case studies Bivouac Office areas Storage halls University of Weimar, Germany 8

9 Renovation Upgrades 1 Upgrades 2 University of Weimar, Germany 9

10 Upgrades 3 Exhibitions Seismic strengthening University of Weimar, Germany 10

11 Seismic strengthening Seismic strengthening Seismic strengthening Story drift comparison UNSTRENGTHENED STRENGTHENED 2-1 0,88 % 0,68 % (-23%) 1-0 2,16 % 1,52 % (-30%) Period changes FREQUENCY (PERIOD) Unstrengthened before 6,93 Hz (0,14 s) Unstrengthened after 2,97 Hz (0,34 s) Strengthened before 6,23 Hz (0,16 s) Strengthened after 5,66 Hz (0,18 s) University of Weimar, Germany 11

12 Ribbed CLT Ribbed CLT ,5 55 Light frame wall CLT wall Ribbed CLT wall Price [ /m2] Timber use Utilization ULS [%] Utilization FIRE [%] [dm3/m2] PSILOS garage system Concept 3 basic shapes 1 to 5 floors 46 to 488 parking spots 7000 /parking space on Facts 13.5 tons/co2/parking spot 5 times lighter than in RC lower foundation cost deassembly reassembly 1 week/floor University of Weimar, Germany 12

13 PSILOS garage system Conclusions Experiments proove that CLT is a perfect material for buildings in seismic areas. Cases show that CLT can be used even for extreme seismic demands (multi-stores construction, building strengthening). Many cases of CLT constructions in seismically unactive areas can be designedwith the use of the material s technical approvals and sensible interpretations of Eurocode 5 guidelines. Conclusions The current state of the European seismic design code (EC8) is far behind the demands of the market (investors, architects) for timber structures. However for lower strucures designing a seismically resistant CLT building is easier than a light timber frame due to simpler details and a more desirable response of the system. More research papers are being publishedon the topic of seismic CLT design every year. University of Weimar, Germany 13

14 Conclusions Thank you for your attention! University of Weimar, Germany 14