膨胀土路堑边坡的滑坡机理分析

膨胀土作为一种特殊土,其路堑边坡开挖之后若不及时防护易出现小规模的浅层滑坡;这类滑坡呈圈椅状体,后缘多出现在坡腰及其附近。为了研究膨胀土路堑边坡的滑坡机理,本文采用数值方法研究了这类边坡浅表风化层、裂隙性及时间效应对滑坡机理及稳定性的影响。研究表明:强度分层、裂隙的存在和蠕变效应共同决定了膨胀土路堑边坡的失稳具有浅层、小规模、渐进性和滑坡后缘通常出现在坡体中部的特点。工程实例和监测结果表明:锚杆框架梁可以有效抑止膨胀土边坡裂隙的扩展和发展,阻止坡体的变形,是这类边坡一种有效的加固方式,值得推广。

Mechanical Analysis of Cut Slope Failures in Expansive Soil Areas

As a special type of soil, expansive soil can be found in almost all countries. It is very easy to induce slips in superficial layers if the cut slopes have not been supported in time. The backscarp of the landslides, the scale of which is small, usually occurs in the middle of the slopes, and seldom happens at the top of the slopes. The toe is usually arcuate in shape. In order to research the forming mechanisms of superficial slides in expansive soil regions, FLAC3D software is used to simulate the effects of cracks and fissures in superficial layers on the deformation of the slope. Meanwhile, a creep model of expansive soil slopes is analyzed. A case study and monitoring results indicate that anchor frame beams can restrain expanding of cracks and fissures, and effectively strengthen the cutting slopes in expansive soil.