Failure-proof performance of tied-back walls during earthquakes is critical to maintaining transportation corridors for emergency vehicles. Yet very little research has been done on the seismic response of tied- back walls. More importantly, there are no formalized procedures for the seismic design of tied-back walls. Possible failure modes have been identified through computer finite element studies: what is lacking is observation of the performance of actual tied-back walls during moderate to large earthquake shaking. During the Whittier Narrows earthquake, a number of tie-back walls for building excavations - mostly temporary - were subjected to moderate earthquake shaking. Because of temporary nature of these walls, the information is available for a relatively short time, after which the data is lost. In addition, eye witness accounts of the excavation response may provide information for interpreting the data. The objective of this research is to collect data on tied-back wall response during the Whittier Narrows earthquake in order to compare the field observation of the performance of the tied-back walls to the results of numerical analyses. This will help validate the analytical models for the performance and damage of tied-back walls to earthquake loading, and it will also help to determine the dependence on wall geometry, soil profile, location of the anchors, tieoff loads, and ground motion. Each case history is being documented in sufficient detail to facilitate comparison between sites with the numerical studies.
