Steven French - US grants

This project involves a comparative analysis of damage to public property caused by the Loma Prieta and Whittier earthquakes. Specific objectives of the study are: (1) to collect a detailed listing of physical damage to public facilities including public buildings, streets, bridges and water sewer systems and document repair and replacement costs for each class of damage; (2) to produce one way descriptive statistics that show the overall damage pattern and the damage pattern for each jurisdiction; (3) to compare the distribution of damage across types of facilities with that experienced in the Whittier Narrows earthquake and test the hypothesis that the proportion of damages for each class is the same; (4) to calculate damage ratios for various systems based on the actual losses and secondary data on the amount and value of property in each case study jurisdiction; and (5) to compare the actual damage experienced in both Whittier Narrows and the Loma Prieta earthquakes to the damage predicted by the ATC-13 damage estimation method and determine the variation of each to the predicted values.

This award is an outcome of the National Science Foundation 07-506 program solicitation "George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) Research" competition. This project is led by the University of Nevada, Reno, and includes subawards to the Consortium of Universities for Research in Earthquake Engineering, Cornell University, Georgia Institute of Technology, North Carolina Agricultural and Technical State University, North Carolina State University, Rutherford and Chekene, State University of New York at Buffalo, and University of California-San Diego. Nonstructural systems represent 75 percent of the loss exposure of U.S. buildings to earthquakes, and account for over 78 percent of the total estimated national annualized earthquake loss. A very widely used nonstructural system is the ceiling-piping-partition system. Ceiling-piping-partition systems consist of several components and subsystems, have complex three-dimensional geometries and complicated boundary conditions because of their multiple attachment points to the main structure, and are spread over large areas in all directions. Their seismic response, their interaction with the structural system they are suspended from or attached to, and their failure mechanisms are not well understood. Moreover, their damage levels and fragilities are poorly defined due to the lack of system-level experimental studies and modeling capability. Their seismic behavior cannot be dependably analyzed and predicted due to a lack of numerical simulation tools. In addition, modern protective technologies, which are readily used in structural systems, have never been applied to these systems. This project integrates multidisciplinary system-level studies that will develop, for the first time, a simulation capability and implementation process for enhancing the seismic performance of the ceiling-piping-partition nonstructural system. The experimental program will use the NEES equipment sites at the University of Nevada, Reno and State University of New York at Buffalo to conduct subsystem and system-level full-scale experiments. A payload project using the Japanese E-Defense shake table facility in Miki, Hyogo, Japan, is planned in coordination with Japanese researchers. Integrated with the experimental effort will be a numerical simulation program that will develop experimentally verified analytical models, establish system and subsystem fragility functions, and develop visualization tools that will provide engineering educators and practitioners with sketch-based modeling capabilities. Public policy investigations are designed to support the implementation of the research results, including the use of representative index buildings and urban planning tools to estimate the cost benefits of the new protective devices and design concepts at both the individual building and the metropolitan area scales.

The results will address implementation barriers and provide public policy rationales for amendments to building codes and standards and related guidelines. The project collaborates closely with industry through a Practice Committee consisting of experts representing all aspects of the ceiling-piping-partition nonstructural systems. This project includes a science museum interface with K-12 students and the general public; summer engineering camps for minority and female students; hands on experience to students of a community college; outreach programs to engineers, architects and industry practitioners; and plans for revisions to building codes, standards, and performance-based earthquake engineering guidelines. Data from this project will be made available through the NEES data repository (http://www.nees.org).