毕威高速公路某边坡变形机制及数值模拟

Deformation Mechanism and Numerical Simulation of a Slope along Bijie-Weining Highway

以贵州毕威高速公路某边坡为例,通过对现有变形特征及路堑边坡开挖形成的临空条件分析,得到坡体的变形机制为:蠕滑-局部拉裂,并已进入匀速蠕滑阶段。运用ANSYS软件建模,运用FLAC3D数值软件计算其主剖面开挖边坡在暴雨工况下的应力-应变分布情况。结果表明:基覆界限附近已形成软弱带,部分土体发生剪切破坏;需尽快放坡并对边坡进行抗滑支挡及设置排水措施,否则软弱带会进一步发展成滑面,导致坡体失稳破坏。

Taking a slope along Bijie-Weining Highway in Guizhou as an example,this paper,by the analysis of current deformation features and the free face condition from cutting slope excavation, obtained the deformation mechanism of the slope as follows： creeping-local tension cracking,and then entering into the stage of uniform creeping. With modeling by ANSYS software,the stress-strain distribution on the principal section of the slope under excavation in the rainstorm condition was calculated with FLAC3 D numerical software. The result shows that weak zone has been formed near the interface between the underlying and overlying rock with part of soil mass subject to shear fracture; thus sloping is required with anti-slide retaining and setting of drainage,otherwise the weak zone would further develop to sliding surface,leading to slope failure.