近年来关于膨胀土边坡的病害处治逐渐转向了柔性防护领域,其中在膨胀土中植入土工格栅就是典型的一种.取十天高速西略段膨胀土加入不同层土工格栅,进行室内剪切试验,研究加筋对膨胀土抗剪强度的影响;再结合现场试验,考察筋材对膨胀土边坡稳定性的影响,以此来探讨加筋膨胀土的抗剪作用机理.试验结果表明:加筋使得剪应力峰值、峰值区域、残余强度以及峰值出现所对应的位移均得到提高;加土工格栅可以有效抑制土样剪切带的发展及土体的双向变形,提高其延性,推迟塑性破坏的出现,改善土体的变形特征,导致破坏模式发生变化;加筋能有效增大土体的黏聚力,而内摩擦角变化不大;加土工格栅能减小坡体的位移变形,增大土体抗滑移强度,提高坡体的稳定性.%In recent years,the disease treatment on the expansive soils slope has gradually turned to flexible prevention,among which planting the Geogrid into expansive soils is one of the most typical examples.This paper studied the effects on the shearing resistance strength of reinforced expansive soils through the indoor shearing test,which added different layers of Geogrid into the expansive soils,which collected on the Shiyan-Tianshui highway.Combining the field test,the effects of geosynthetics on the expansive soil slope stability were examined as well.Therefore,the shearing resistance mechanism of reinforced expansive soil was discussed.The results showed that the shear stress peak value,peak region,residual strength as well as the corresponding displacements to every peak value all increased because of Geogrid reinforcement;Geogrid can effectively prevent the development and double-deformation of the soil sample so as to increase its ductility,postpone the plastic failure,improve the deformation characteristics and lead to the change on failure mode;Geogrid reinforcement can greatly improve the cohesive force of the soil sample with little change on internal fraction angle;the Geogrid can decrease the displacement deformation of slope and increase the anti-sliding strength to improve the slope stability.
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