PEER Reports

Liquefaction-induced lateral ground displacement has caused significant damage to pile foundations during past earthquakes. Ground displacements due to liquefaction can impose large forces on the overlying structure and large bending moments in the laterally displaced piles. Pile foundations, however, can be designed to withstand the displacement and forces induced by lateral ground displacement. Piles may actually “pin” the upper layer of soil that would normally spread atop the liquefied layer be low it into the stronger soils be low the liquefiable soil layer. This phenomenon is known...

By virtue of their locations, bridges that cross bodies of water are particularly likely to be damaged by lateral spreading of liquefied soils. The behavior of these soils can cause unusual forms of seismic demands on bridges and their foundations, ranging from rapid modifications of input motion amplitudes and frequency contents to high levels of kinematic loading associated with permanent deformations of the supporting soils. This report describes the application of the PEER methodology of performance-based earthquake engineering to a bridge structure founded on liquefiable soils. In...

We present a model for estimating horizontal ground motion amplitudes caused by shallow crustal earthquakes occurring in active tectonic environments. The model provides predictive relationships for the orientation-independent average horizontal component of ground motions. Relationships are provided for peak acceleration, peak velocity, and 5-percent damped pseudo-spectral acceleration for spectral periods of 0.01–10 sec. The model represents an update of the relationships developed by Sadigh et al. (1997) and includes improved magnitude and distance scaling forms as well as hanging-wall...

The Pacific Earthquake Engineering Research Center is leading an initiative to develop guidelines for new high-rise construction that will meet intended safety and performance objectives following future earthquakes, particularly when alternative means of design are employed. An initial task of this initiative was to investigate the issues associated with identifying seismic performance equivalent to that achieved by code and whether a higher seismic performance should be targeted for these buildings. Many stakeholders were interviewed for this purpose, and a workshop was convened to...