三维土工网防护边坡整体稳定性分析

Analysis of the Overall Stability of the Three Dimensional Geonet Protected Slope

针对三维土工网护坡技术的前期阶段不断出现的边坡整体失稳现象,基于三维土工网护坡技术的作用机理,采用强度系数折减法,利用ABAQUS建立土工网防护边坡的三维有限元模型,以坡肩特征点的位移突变情况作为边坡失稳判断的标准,分别计算和比较了不同降雨条件下土工网防护边坡和不含土工网边坡的安全系数,探究了边坡失稳时坡体内部塑性区的发展情况和位移分布规律,并利用室内边坡抬升破坏试验分析比较了两种边坡的破坏抬升角度和最终破坏情况,与数值模拟分析结果进行比较。结果表明:土工三维网在一定程度上可以提高边坡的整体稳定性,但作用影响较小;降雨强度的大小对边坡稳定性的影响较为明显;在土工网和铆钉共同作用下,土工网和其覆盖的土体共同作用,呈现较好的整体性。

Global instability has been constantly appearing in the early stage of application of three dimensional geonet slope protection. In this paper, we develope a three-dimensional finite ele- ment model on three dimensional geonet reinforced slope by using ABAQUS. The displacement at characterization point in slope shoulder was used to determine the instability of the slope. We computed and compared the safety factor of slope with and without geonet under different rainfall conditions and explored the plastic zone distribution and slope displacement at the instability point. Lifting angle and damage mode of above two kinds of the slope were experimentally inves- tigated in slope lifting test analysis, and test results are compared with simulation. Both experi- mental and numerical results show that three-dimensional geonet can only slightly improve the stability of slope. However, the intensity of the rainfall has more pronounced effects on the slope stability. We also observed that with the application of both geonet and rivets, the integrality of slope can be improved.