滑坡堆积体粗粒滑带土强度参数确定方法研究

Determination method for strength parameters of coarse slip-zone soil in landslide deposit body

岩土体抗剪强度是分析边坡稳定性的重要力学参数。由于目前的方法限制,获取未扰动的原状样较为困难,因而很难准确地获取其强度参数,也就不能对滑体的稳定性做出正确的评价。本文通过现场获取滑带土样,进而获得各地段相应的密度、含水率等物理指标,以重力压密原理为基础,在室内开展相匹配的强度试验,获得强度参数,并对原状样和压密样的试验结果进行了对比,压密样的强度参数比原状样的要大。同时建立了滑带土孔隙比、含水量与摩擦系数、黏聚力的关系,用试验获得的关系式可以快速准确地获取不同部位滑带土的强度参数。由此进行边坡稳定性计算将更为合理。

The shear strength of soil is an important mechanical parameter for the analysis of slope stability, but it is difficult to excavate the massive undisturbed soil, and is difficult to accurately obtain the strength parameters, so the evaluation of slope stability can＇ t be carried out properly. Through the undisturbed samples excavated in the field, the corresponding density, moisture content and other physical indices in different sections are obtained. Based on the principle of the gravitational compaction, the corresponding laboratory strength tests are carried out to obtain the strength parameters. The strength parameters of the compaction samples from direct shear tests are higher than that of the undisturbed soil, and the relationship between the void ratio, the water content and the friction coefficient, cohesion are established. Based on the equation obtained from the tests, the strength parameters of the slip-zone soil in different sections can be obtained fast and truly, so the stability calculation of slope will be more reasonable.