钢箱边界效应振动台试验研究

为分析桩的动力响应和钢箱的边界效应,设计一个带有泡沫边界、滑动边界以及摩擦边界的钢箱,并进行桩土相互作用的振动台试验.试验结果表明:1)惯性效应作用下,桩顶的地震响应最大;2)钢箱不同埋深处,地震响应不一,底部最小,中部大于底部和上部;3)泡沫边界会影响土体内介质的加速度响应——无泡沫边界情况下土体内介质的加速度响应偏大.所以,在进行桩土动力相互作用的振动台试验时建议增设泡沫边界.

Shaking table test on boundary effect of steel box for pile-soil interaction research

This article introduces a steel box designed for pile-soil dynamic interaction shaking table experiment. In order to minimize the boundary effect, the four sides and bottom of the steel box were set foam boundary, sliding boundary and friction boundary,respectively. By the shaking table test of pile-soil dynamic interaction, the distribution of acceleration response in different embedded depth and the effect of foam boundary on test results were investigated.The following conclusions can be drawn from this study: (1) the seismic response is the largest in pile head due to the effect of inertia; (2) the seismic response is different in different embedded depth, i.e., at the bottom of steel box is the smallest and at the central is the largest; (3)the foam boundary has noSeffectSon the acceleration response on the pile head and the surface of the shaking table except for the location in the earth. The acceleration response for the case with no foam boundary is larger than the case with foam boundary and therefore, the foam boundary is required in pile-soil interaction shaking table test.