关键词: 脉冲地震动, 倾斜液化场地, 桩基础, 数值模拟, 地震响应, 地震动参数, 相关性分析

Abstract: In this paper, the seismic responses of inclined liquefaction site-pile-structure system under near-field pulsed and non-pulsed ground motion were studied. Firstly, a finite element model of inclined liquefaction site-pile-structure system was established based on the finite element platform OpenSees, and the reliability of the numerical model was verified by comparing with the results of large-scale shaking table test. On this basis, the finite element model of typical inclined liquefaction site-pile-structure system was established, the seismic response laws of the system under near-field pulsed and non-pulsed ground motion were compared and analyzed, and the correlation analysis between ground motion intensity index and seismic response was carried out. The results show that compared with the non-pulsed ground motion, the residual displacement of the site increases obviously under the near-field pulsed ground motion, especially at the top of the loose sand layer, which increases by about 40%. Pile bending moment and pile residual displacement increase significantly, especially at the pile top. The correlation between the ground motion intensity index and the response under non-pulsed ground motion is higher than that under pulsed ground motion. Three strength parameters with good correlation, i.e. PGV/PGA (peak ground velocity/ peak ground acceleration), AI (Arias intensity) and T_m(mean period), can indicate the influence of ground motion on the failure response of liquefaction site-pile-structure system to a certain extent.

Key words: pulse ground motion, inclined liquefaction site, pile foundation, numerical simulation, seismic response, ground motion parameters, correlation analysis