Multiple-level earthquake-resistant design strategy for precast concrete frames with semi-rigid connections: A case study

Abstract

The design of precast concrete (PC) structures with semi-rigid connections is primarily based on the design of cast-in-suit structures by adjusting the relevant parameters of PC connections. However, it is necessary to further verify whether the seismic collapse resistance capacity of these PC structures meets the requirements, and to examine how to achieve the optimal seismic resistance design of PC structures. To explore a more concise and effective design scheme for PC structures, the influence of different PC connection parameters and the number of structural stories on the collapse resistance capacity of PC structures is discussed based on a case study. In this work, we set three series of 8-story PC structures and one series of 18-story PC structures, based on different PC connection parameters. Firstly, a simplified algorithm of the inter-story drift (ISD) ratio, based on a modified Muto’s method, is performed to preliminarily screen PC structures subjected to frequent-level earthquakes, and the lower limit value of the semi-rigid connection coefficient of each series of structures can be determined. Next, based on the modal pushover analysis and the capacity spectrum, the ISD ratio of the structures subjected to rare-level earthquakes is analyzed to further screen out the structures that do not meet the specification limits. The distribution ratio of the hysteretic energy in each story of the PC structures is discussed using time history analysis. Then, in the collapse stage, based on a global damage model and incremental dynamic analysis, the collapse state points of the structure can be obtained so that the collapse probability curve of each PC structure is determined, and the collapse safety margin of PC structures can be analyzed. PC structures can be further screened based on the collapse margin ratio (CMR), and the influences of PC connection parameters on the CMR and failure path of PC structures are assessed. Finally, the optimization of structures with semi-rigid PC connections based on multilevel seismic action is realized.