关键词: 斜坡, 地震动强度, 正弦波, 天然地震波, 加速度响应峰值, 放大系数

Abstract: Based on large-scale shaking table tests, using the pre-processed peak ground acceleration(PGA) and its amplification factor, taking slopes with two types of lithology variations including high strength materials overlying low strength materials and low strength materials overlying high strength materials as the research objects, this paper investigates systematically the change laws of the horizontal and vertical accelerations in different slope levels with the gradual increasing intensity, under sine waves and crude seismic waves. Analysis shows that: ① When crude seismic waves are loaded, the PGAs in two directions both increased as input waves strengthened, while their corresponding amplification factors increased first, then gradually decreased into stability change. ② When sine waves are loaded, the PGAs in two directions also increased as input waves strengthened, however, their corresponding amplification factors still increased slowly all the time, which indicates the weaker nonlinearity. ③ Under the horizontal and vertical seismic action of the same magnitude, the acceleration amplification appears respectively in the upper part and in the lower part of the two slope models. In addition, several extremum zones of accelerations appear at the bottom, middle and top of slope models. ④ Under the horizontal seismic action, the effect of low frequency is stronger than that of high frequency, furthermore, with the same seismic wave, the acceleration responses in slope with high strength materials overlying low strength materials are stronger than those in the other slope; while under the vertical seismic action of the same magnitude, the results are contrary. The research provides a guidance and reference to quakeproof and post-disaster reconstruction in the high seismic hazard zones.

Key words: slope, ground motion intensity, sine wave, crude seismic wave, peak ground acceleration, amplification factor