Development of Testing Protocol for Cripple Wall Components (PEER-CEA Project), Peer Report 2020-15


This  report  is  one  of  a  series  of  reports  documenting  the  methods  and  findings  of  a  multi-year,  multi-disciplinary  project  coordinated  by  the  Pacific  Earthquake  Engineering  Research  Center  (PEER) and funded by the California Earthquake Authority (CEA). The overall project is titled “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings,” henceforth referred to as the “PEER–CEA Project.”

The  overall  objective  of  the  PEER–CEA  project  is  to  provide  scientifically-based information  (e.g.,  testing,  analysis,  and  resulting  loss  models)  that  measure  and  assess  the  effectiveness of seismic retrofit to reduce the risk of damage and associated losses (repair costs) of  wood-frame  houses  with  cripple  wall  and  sill  anchorage  deficiencies  as  well  as  retrofitted  conditions that address those deficiencies. Tasks that support and inform the loss-modeling effort are: (1) collecting and summarizing existing information and results of previous research on the performance   of   wood-frame   houses;   (2)   identifying   construction   features   to   characterize   alternative  variants  of  wood-frame  houses;  (3)  characterizing  earthquake  hazard  and  ground  motions  at  representative  sites  in  California;  (4)  developing  cyclic  loading  protocols  and  conducting  laboratory  tests  of  cripple  wall  panels,  wood-frame  wall  subassemblies,  and  sill  anchorages to measure and document their response (strength and stiffness) under cyclic loading; and (5) the computer modeling, simulations, and the development of loss models as informed by a workshop with claims adjustors.

This  report  is  a  product  of  Working  Group  3.2  and  focuses  on  Loading  Protocol Development for Component Testing.  It presents the background, development process, and  recommendations for a quasi-static loading protocol to be used for cyclic testing of cripple wall components of wood-frame structures.  The recommended loading protocol was developed  for  component testing to support the development of experimentally informed analytical models for cripple wall components.  These analytical models are utilized for the performance-based  assessment of wood-frame structures in the context of the PEER–CEA Project. 

The recommended loading protocol was developed using nonlinear dynamic analysis of representative multi-degree-of-freedom (MDOF) systems subjected to sets of single-component ground motions that varied in location and hazard level. Cumulative damage of the cripple wall components of the MDOF systems was investigated. The result is a testing protocol that captures the loading history that a cripple wall may experience in various seismic regions in California.

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Farzin Zareian
Joel Lanning
Publication date: 
November 5, 2020
Publication type: 
Technical Report
Zareian, F., & Lanning, J. (2020). Development of Testing Protocol for Cripple Wall Components (Report No. 2020/15). Pacific Earthquake Engineering Research Center (PEER).