High-Force-to-Volume Seismic Dissipators Embedded in a Jointed Precast Concrete Frame

摘要

An experimental and computational study of an 80-percent scale precast concrete 3D beam-column joint subassembly designed with high force-to-volume (HF2V) dampers and damage-protected rocking connections is presented. A prestress system is implemented using high-alloy high-strength unbonded thread-bars through the beams and columns. The thread-bars are posttensioned and supplemental energy dissipation is provided by internally mounted lead-extrusion dampers. A multilevel seismic performance assessment (MSPA) is conducted considering three performance objectives related to occupant protection and collapse prevention. First, bidirectional quasi-static cyclic tests characterise the specimen's performance. Results are used in a 3D nonlinear incremental dynamic analysis (IDA), to select critical earthquakes for further bidirectional experimental tests. Thus, quasi-earthquake displacement tests are performed by using the computationally predicted seismic demands corresponding to these ground motions. Resulting damage to the specimen is negligible, and the specimen satisfies all performance objectives related to serviceability, life-safety, and collapse prevention.