PEER Reports

The first widespread observations of damage attributed to liquefaction were made in the 1964 Niigata, Japan, and 1964 Alaska earthquakes. In numerous earthquakes since, liquefaction has been deemed responsible for significant damage to buildings and bridges. Liquefaction has been studied extensively over the past 35 years, and substantial advances have been made in understanding the development and effects of this phenomenon. These advances have led to a series of practical procedures for evaluating the potential for occurrence and for estimating its effects. These procedures, however, are...

The 2001 Nisqually earthquake, which had a moment magnitude of 6.8, damaged at least 78 bridges in western Washington State. Reports of damage sustained by bridges during this earthquake were used to correlate the likelihood of damage with the following parameters: distance to the epicenter, estimated peak ground acceleration, estimated spectral acceleration at periods of 0.3 s, 1.0 s, and 3.0 s; year built; and type of bridge. This goal was accomplished by collecting reports of bridge damage from state and local agencies, and comparing them with the population of bridges listed in the...

Compared to structural systems, there is little basic research on the performance of nonstructural systems and building contents, and little empirical data on damage to specific systems, from past earthquakes. This report describes approaches to nonstructural hazards mitigation at the University of California, Berkeley, and focuses on design and cost estimates for anchoring the contents of laboratories. Research equipment is grouped into five categories: (1) tanks and cylinders, (2) unique equipment and experimental setups, (3) heavy equipment, (4) storage elements, and (5) benchtop items...

A major component of a building-specific seismic loss analysis is the estimation of repair costs in future earthquakes. A number of uncertain variables contribute to the uncertainty in these cost estimates. Among these are ground-shaking intensity, details of the ground motion, mass, damping, and
force-deformation behavior, component fragility, repair methods, contractor’s direct costs, and contractor’s overhead and profit, among others. This report addresses which of these significantly contribute to the overall uncertainty in future economic performance. We examine gross sensitivity...