PEER Reports

Strong ground motions from the M_w 6.6 2007 Niigata-ken Chuetsu-oki earthquake were recorded by a free-field downhole array installed near the Service Hall at the Kashiwazaki-Kariwa nuclear power plant. Site conditions at the array consist of about 70 m of medium-dense sands overlying clayey bedrock, with ground water located at 45 m. Ground shaking at the bedrock level had geometric mean peak accelerations of 0.55 g, which reduced to 0.4 g at the ground surface, indicating nonlinear site response. Ground settlements of approximately 15±5 cm occurred at the site. A site...

The primary goal of this project was to develop strategies for selecting standardized sets of ground motions for use by the Pacific Earthquake Engineering Research Center’s Transportation Research Program. The broad research activities of the Transportation Research Program require ground motions for use in a variety of applications, including analysis of structural and geotechnical systems at locations throughout California (or other active areas where seismic hazard is dominated by mid- to large-magnitude crustal earthquakes at near to moderate distances). The systems of interest may be...

Broadband ground motion simulation procedures typically utilize physics-based modeling of source and path effects at low frequencies coupled with semi-stochastic procedures at high frequencies. The high-frequency procedure considered here combines a deterministic Fourier amplitude spectrum that is a function of closed-form source, path, and site models with a random phase. Previous analysis of the simulation procedure in the ShakeOut exercise demonstrated faster distance attenuation and lower intra-event dispersion of high-frequency ground motions than in empirical ground motion equations...

The severe traffic delays caused by traditional cast-in-place bridge construction can be reduced by precasting components off site and assembling them rapidly on site. In seismic regions, connecting precast concrete columns and beams creates difficulties because the connections often occur at the locations of large, inelastic moment reversals. Previous researchers have addressed this challenge through the development of a “Large-Bar, Large Duct” [Pang et al. 2008] and a “Socket” connection [Haraldsson et al. 2011]. Both connections are easy to construct and robust under simulated seismic...