往复移动荷载下超固结软黏土重力模型试验研究

研发了能够进行往复移动荷载下超固结软土地基的室内重力模型试验装置,并基于该试验平台开展了上海浅层超固结饱和软黏土的重力模型试验研究。通过一系列试验,揭示了超固结饱和软黏土地基在往复移动荷载下的累计孔压及累计变形随往复次数及动载幅值的时空演化规律。试验表明,深层土体处的超孔压动力响应明显较浅层的动力响应低,但其动力响应更为迅速。同时,土体在交通荷载行进方向上的动力响应比其他方向上更为强烈,其孔压衰减也最不明显。此外,动载幅值越大,初期的塑性变形和后期的位移增量也明显变大,并且不同水平位置处的差异沉降也越大。

Gravity model testing overconsolidated soft clay under repeated moving loads

A gravity model test device is developed to simulate overconsolidated soft clay under repeated moving loads. Using this device, the model tests on Shanghai shallow overconsolidated saturated soft clay are carried out. Through a series of tests, it is revealed that temporal and spatial variation of the accumulated pore pressure and deformation about overconsolidated saturated soft clay foundation with the number and amplitude of changing repeated moving loads. The test results show that the dynamic response of the excess pore pressure in the deep soil is obviously lower than that of shallow soil, but its peak value comes earlier. At the same time, the dynamic response of soil in the direction of moving loads is stronger than that in other directions, and the dissipation of the excess pore pressure in that direction is also the least obvious. In addition, with the amplitude of increasing dynamic loads, the plastic deformation at the initial stage and the displacement increment at the later stage get larger, and the difference of settlements at different horizontal positions becomes larger too.