Towards Earthquake-Proof Wood Buildings

Transcription

1 Towards Earthquake-Proof Wood Buildings Full-scale shake table test of a two-story mass timber building Presented by Shiling Pei, Ph.D. P.E. Colorado School of Mines Disclaimer: This presentation was developed by a third party and is not funded by WoodWorks or the Softwood Lumber Board.

2 The Wood Products Council is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES), Provider #G516. Credit(s) earned on completion of this course will be reported to AIA CES for AIA members. Certificates of Completion for both AIA members and non-aia members are available upon request. This course is registered with AIA CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

3 The big IF your client don t want to settle for codeminimum seismic performance (i.e. life safety)... There are some New Mass Timber Systems that can make a difference

4 Idea 1: Post-tensioned CLT rocking walls

5 Building Ready for Test A total of 14 earthquake tests conducted How to plan a full scale test? Know what to look for Starts with small ones Ramp it up Keep pushing until you get what you want (and be safe!) SLE: Service Level Earthquake (frequent) DBE: Design Basis Earthquake (Design code) MCE: Maximum Considered Earthquake (2500 yr return period)

6 Public Test (Test No.6) This should survive two Northridge back to back Check project website: NHERITallWood.mines.edu for more test footage!

7 The MCE+ Shake (Test No.14) 5% drift Close up on Rocking Wall Second story wall & column

8 Building Performance White noise period 0.85 sec Maximum drift 5% (test 14) Maximum base shear 430 kn (96 kips) (Building total weight 171 kips) Diaphragm behaved rigidly Some PT bars yielded in MCE events (~150 kips max tension) No damage to wood Minimal residual drift Journal paper under ASCE J. of Structural Eng.

9 Removal of the Rocking Wall No wood damage that needs structural repair after 14 earthquakes

10 Ideal 2: Reparable Rocking Wall A new Rocking wall design without post-tension to save cost Damage-free in small EQ Enable easy repair for big ones A proprietary system developed by

11 Response under MCE Northridge Shake Now let s see what happensj

12 Repairable Planned Locations

13 You can design this by hand (13 tests) Blind Prediction Results 4% drift 2% drift Jin et al. (2018) Simplified Mechanistic Model for Seismic Response Prediction of Coupled CLT Rocking Walls Accepted In-Press, J. Structural Eng.

14 Conclusions? 1. There are ways to design a mass timber building to be structurally resilient against earthquakes 2. We are not done yet, more research to come in the near future to develop and demonstrate mass timber performance against hazards For Design Office: Currently a Wood Innovation Project going on to develop Design Provisions for mass timber rocking walls. Seismic Design Specification for Cross Laminated Timber Rocking Wall Systems ( ) A collaboration between Colorado School of Mines, KPFF, AWC, FPInnovations, and WoodWorks. Looking for adoption into SDPWS. Readily deployable for 2~8 stories in high seismic regions. And if you want to go taller...

15 2020 at San Diego Shake Table The building will utilize post-tensioned rocking wall and be finished with non-structural components and building envelop. Preliminary design currently underway. Design will be finalized in Construction starts Summer 2020 Tests starts October 2020

16 Fast-Forward to November 2020 Now seismic tests are done Opportunity to conduct full-scale fire test on a 10- story mass timber building. Likely the only chance to do such a test anywhere worldwide. Largest building structure tested, regardless of material.

17 SHAKE & BAKE 2020 Will be the tallest building ever tested on a shake table. And YES, we also plan to burn it. Please contact us if you: Are interested in support these research efforts (Sponsorship) have a product, system, or idea you want to test (R&D Collaboration) Spei@mines.edu

18 Acknowledgement The Materials from this presentation are results from multiple research projects supported by National Science Foundation (CMMI , CMMI , CMMI , CMMI , CMMI , CMMI ) and multiple industry partners. The financial support of these sponsors is greatly appreciated. Thanks to the financial support or material donation from our collaborators on the Two-story testing program

19 QUESTIONS? This concludes The American Institute of Architects Continuing Education Systems Course Shiling Pei Colorado School of Mines