合肥地铁车站基坑膨胀土有荷条件下的变形规律研究

Study on swelling law of expansive soil in foundation pit of Hefei metro station under loading condition

为了考察合肥地区膨胀土的膨胀特性,选取合肥地铁车站基坑膨胀土进行了击实土样的有荷膨胀率试验,研究膨胀土的膨胀时程曲线特征及其有荷膨胀率与初始含水率、压实度、荷载的关系。试验结果表明:有荷膨胀时程曲线可分为等速膨胀、减速膨胀、缓慢膨胀阶段,初始条件不同膨胀时程曲线特征也不同;有荷膨胀率随初始含水率的增加而线性降低,有荷膨胀率与荷载的对数呈线性关系;压实度对有荷膨胀率的影响不显著。

In order to investigate the swelling properties of expansive soil in Hefei, the loading swelling ratio experiments of compacted soil in foundation pit of Hefei subway station were carried out. The expansion time curve characteristics of expansive soil and the relationship between loading swelling ratio and initial moisture content, compaction degree ancl loading were analyzed. The results showed that the loading expansion time curve can be divided into such three phases as constant expansion, descending expansion and slow expansion, the expansion time curve characteristics are different under different initial conditions, loading swelling ratio decreases linearly with the initial moisture content increasing, there is a linear relationship between the loading swelling ratio and loading logarithm, and the influence of the compaction degree on the loading swelling ratio is not significant.