DATA AND DISCOVERY ON LIQUEFACTION-INDUCED LATERAL GROUND DEFORMATIONS

by Fang Liu, PhD candidateSonny Astani
Dept. of Civil and Environmental EngineeringABSTRACT:Liquefaction-induced lateral ground deformations posed considerable threatens to lifeline systems in urban areas in the past. In the practice of liquefaction evaluation in geotechnical earthquake engineering, empirical relations and procedures received special appreciation. They benefited from vast amount of case histories collected and documented after major earthquakes. Advances of technologies transformed the way collecting, documenting, distributing, and utilizing this perishable information. The research effort was concentrated on exploring the feasibility of new information technologies for managing and distributing data pertinent to liquefaction damages, and on deriving and assessing data-driven models pertinent to liquefaction-induced lateral ground deformation.
New information technologies were demonstrated for generating and distributing post-earthquake reconnaissance reports. The newly emerging technique, known as embedded metadata in pictures, allowed portable pictures that possessed embedded information. The metadata-based approach enhanced the automation level in generating PER reports, and enabled a complex of possible applications. A lightweight Information system was developed for distributing collected case histories of liquefaction together with relevant geotechnical information over the Word Wide Web. Supported by a customized database and external data from remote servers, the proposed system enabled dynamic and rapidly responsive Web applications to share information through the Internet.
The performance of gently sloping grounds was investigated using sliding block theory under statically unstable conditions due to temporary loss in shear strength. The major efforts were concentrated on quantifying in probabilistic terms the contribution of earthquake motions to the amplitude of lateral deformations once the instability had triggered. The Monte Carlo simulation was performed for a set of actual strong motion records and an idealized infinite gentling sloping ground in order to derive the empirical relations.
Finally, a case study was presented as an example to demonstrate the value of case histories collected over years, and to evaluate the performance of three existing empirical models for liquefaction-induced lateral ground deformations. Empirical relations were integrated in a GIS system, leading to maps of liquefaction severity and liquefaction-induced lateral deformations.

Location: Kaprielian Hall (KAP) - 209

Audiences: Everyone Is Invited

Contact: Evangeline Reyes