Abstract:In the western region of China, which is rich in hydropower resources, problems such as deep riverbed cover and proximity to seismogenic fault zone are unavoidable. The liquefaction of weak soil layer is one of the main contents of safety evaluation of earth-rock dams. In this paper, aiming at the high asphalt concrete core dam built on the deep overburden layer with easily liquefied interlayer, an improved pore water pressure-deformation coupling effective stress analysis method (IES method) is proposed. The liquefaction characteristics of weak soil layer and its influence on the dynamic response under near-fault ground motions are studied. The results show that the liquefaction zone obtained by the total stress method is much larger than that by the effective stress method. Pulse characteristics make the pore pressure of most characteristic points in soft soil layer rise sharply in a short time, triggering liquefaction quickly; Dynamic pore pressure makes the acceleration of dam top and bottom decrease by 20%~30%. Under the action of pulsed ground motion, the dynamic pore pressure makes the maximum settlement of the dam crest increase by 35%, and the development process of vertical settlement increases significantly in the pulse period, which poses a serious threat to the seismic safety and stability of the dam body.
李闯,宋志强,刘升欢. 近断层地震动作用下易液化深厚覆盖层场地上高土石坝动力响应[J]. 振动与冲击, 2023, 42(17): 228-237.
LI Chuang, SONG Zhiqiang, LIU shenghuan. Dynamic response of high earth-rock dam on site with easily liquefied and deep overburden under near fault ground motion. JOURNAL OF VIBRATION AND SHOCK, 2023, 42(17): 228-237.
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