土工合成材料加筋边坡滑移带的模拟分析

Simulated Analysis of Patterns of Shear Bands in Geosynthetic Reinforced Slopes

用有限元分析方法和图形可视化技术,计算生成加筋边坡的剪切破坏带,模拟边坡破坏的渐进过程,结合与加筋土平面应变直剪试验以及加筋边坡离心模型试验结果的比较,研究加筋边坡的滑移带形态.结果表明加筋边坡呈现出与素土边坡不同的破坏形态,筋材拉伸模量和加筋密度不同,剪切滑移带形态也不相同.随着筋材拉伸模量和加筋层数增大,边坡的滑动屈服带宽度增宽并向边坡内移动;加筋层增加到某一密度时,剪切屈服带将出现在地基中;与未加筋边坡相比,加筋边坡上部较难出现塑性破坏,顶部不易出现裂缝;同时,加筋边坡延性提高,坡顶塌滑程度趋缓.

The finite element method was employed to automatically produce shear bands in reinforced slopes and to simulate the progressive failure, and the calculation results agreed well with the observations in direct shear tests on reinforced soil and centrifuge tests of reinforced slope models. The finite element results showed that the slopes with and without reinforcements differed greatly in the patterns of shear bands, and the reinforced slopes with different density and modulus also resulted in various patterns of shear bands. With the increase of reinforcement density and modulus, the shear bands in reinforced slopes became wider and tended to move into the slopes. And to a certain extent, the shear bands went through the foundations of slopes. Moreover, compared with the unreinforced slopes, in the upper reinforced slopes, the shear failure became relatively difficult and less crack appeared on the top. Meanwhile, the collapses of the reinforced slopes seemed much more flexible and ductile.