RESEARCH AND DEVELOPMENT OF AN OPTIMUM DEVICE TO REDUCE SEISMIC STRUCTURAL POUNDING DAMAGE

DURING THE 1989 LOMA PRIETA EARTHQUAKE, IMPACT OF ADJACENT BUILDINGS, KNOWN AS POUNDING, CONTRIBUTED TO DAMAGE IN SEVERAL HUNDRED STRUCTURES IN THE SAN FRANCISCO BAY AREA. IN ADDITION, DURING THE 1985 MEXICO EARTHQUAKE, POUNDING WASIDENTIFIED AS PRESENT IN OVER 40% OF COLLAPSED OR SERIOUSLY DAMAGED BUILDINGS AND WAS IDENTIFIED AS BEING RESPONSIBLE FOR 15% OF THE COLLAPSES. IN FACT, EXAMPLES OF BUILDING DAMAGE DUE TO POUNDING HAVE BEEN OBSERVED IN ALMOST EVERY MAJOR EARTHQUAKE. POUNDING OF ADJACENT BUILDINGS OCCURS DURING EARTHQUAKES DUE TO INADEQUATE BUILDING SEPARATION WHICH HAS RESULTED SINCE CURRENT BUILDING CODES DO NOT ADEQUATELY ADDRESS THIS ISSUE. BECAUSE OF THE SERIOUS POTENTIAL FOR SEISMIC STRUCTURAL POUNDING TO CAUSE SIGNIFICANT DAMAGE IN FUTURE EARTHQUAKES, EFFICIENT TECHNIQUES ARE NEEDED TO RETROFIT AND UPGRADE CLOSELY SPACED ADJACENT BUILDINGS. PROPOSED HEREIN IS A RESEARCH AND DEVELOPMENT PROGRAM TO DEVELOP POUNDING REDUCTION DEVICES (PRDS) FOR SUCH BUILDINGS. THE RESEARCH IS AIMED AT DEVELOPING A DESIGN AND ANALYSIS METHODOLOGY, THE HARDWARE SPECIFICATIONS FOR THE DEVICE, AND METHODS OF INSTALLATION. CAREFUL CONSIDERATION IS GIVEN TO SYSTEMATIC TREATMENT OF UNCERTAINTIES IN KNOWLEDGE OF THE PROPERTIES OF THE EXISTING BUILDINGS AND IN PREDICTING FUTURE EARTHQUAKE GROUND MOTIONS. THESE UNCERTAINTIES MAY PLAY A SIGNIFICANT ROLE IN OPTIMIZING THE MECHANICAL PROPERTIES OF THE PRD. THE PHASE I RESEARCH WILL INVESTIGATE THE ECONOMICFEASIBILITY OF INSTALLING PRDS, DEVELOP PROMISING MECHANICALDESIGN CONCEPTS FOR THE PRD, AND DEVELOP AND DEMONSTRATE, VIA AN EXAMPLE APPLICATION, THE ANALYSIS METHODOLOGY.