土的卸荷回弹试验及其时间过程的计算方法

Swelling tests on soils and simulation method for unloading-swelling process

主要进行两方面的研究:1进行了土的回弹试验研究。用两种制备土样,进行了加卸荷循环试验研究。通过试验,研究了固结系数/回弹系数在试验过程中的变化规律。通过试验证实,固结系数与回弹系数不是一个固定的常数,是一个以加卸荷过程为周期循环重复变化的过程因子。研究比较了吸水回弹与吸气回弹对试验结果的影响,结果表明,吸水和吸气对回弹的影响不大。2研究探讨了变Cv固结/回弹计算方法,进行了两种重塑土的加卸荷循环全过程比对和两种原状土卸荷全过程比对,理论计算与试验吻合很好,证实了变Cv变形过程计算方法用于固结/回弹变形计算的科学性与合理性,证明回弹是固结的逆过程。

The time-rate of swelling is investigated. The variation of the consolidation coefficient in swelling process and the similarity between absorbing water and absorbing air during the process are studied through experiments. The test results show that the coefficient of consolidation keeps changing in both processes of the consolidation and swelling, ranging up to 3 orders of magnitude. The coefficient of consolidation is not a fixed parameter but a process factor which repeats in each loading and unloading. The feasibility of applying the nonlinear consolidation theory in swelling process is studied. The time-varying Cv method for consolidation and swelling is proposed, and the parameters can be obtained by fitting the experimental results. The settlement and swelling deformation obtained by the proposed method are in good agreement with the experimental results in both loading and unloading processes.