Property verification of triple pendulum™ seismic isolation bearings

This paper presents the process for establishing and validating the design properties of Triple Pendulum™ seismic isolation bearings which were utilized to achieve the superior seismic performance of the New San Bernardino Court facility. The analysis parameters of the nonlinear elements used in the analysis model representing the seismic isolation bearing properties were confirmed through a prototype bearing test program and specification completed during the construction document design phase. The prototype test program and specification was developed considering ASCE 7-05 Chapter 17 requirements and preliminary structural analysis results including horizontal and vertical force-displacement characteristics, as well as axial load demands on the bearings. The final prototype test results verified the characteristic properties of the bearings at various vertical loads and displacements at real-time earthquake motions and the results validated the assumed properties used in the structural analysis and design. The real-time dynamic test program extends current ASCE 7 prescriptive requirements.