围压及含水量对重塑膨胀土抗剪强度的影响

为研究围压及含水量对重塑膨胀土抗剪强度的影响,以及进一步确定不同围压及不同含水量与重塑膨胀土抗剪强度的计算公式,分别对含水率为8.5%、10.0%、12.0%的新疆哈密地区膨胀土进行围压为100、150、200 k Pa的不固结不排水三轴直剪试验(UU)。试验结果表明:干密度和含水量一定时,围压越高,重塑膨胀土抗剪强度越大,围压越低,抗剪强度越小。干密度一定时,含水率越高,重塑膨胀土的抗剪强度指标越小,抗剪强度越低,含水率越低,重塑膨胀土的抗剪强度指标越大,抗剪强度越高。通过对试验结果的进一步分析发现黏聚力、内摩擦角和含水率呈良好的线性关系,得出含水率、围压和重塑膨胀土抗剪强度计算公式,计算值与试验值有较高的相符程度,为新疆哈密地区重塑膨胀土的施工提供了一定的理论依据。

Effects of confining pressure and water content on shear strengthof expansive soil

In order to study the influence of confining pressure and water content on shear strength of the expansive soil, the calculation formula of the shear strength on the expansive soil with different confining pressure and different water content were determined. Remolded expansive soil of Xinjiang hami which is water content of 8.5%, 10.0% and 12.0% is carried out three axis direct shear test under confining pressure of 100, 150 and 200kPa respectively. The results showed that: if the dry density and water content is certain, The higher the confining pressure is, the greater the shear strength of the expansive soil is, the lower the confining pressure is, the smaller the shear strength is. When the dry density is constant, if the moisture content is higher, the shear strength indexes and the shear strength of remolded expansive soil are smaller. When the dry density is constant, if the moisture content is lower, the shear strength indexes and the shear strength of remolded expansive soil are higher.