土工格栅加筋土石坝的试验和数值模拟研究

为进一步了解土工格栅加筋土石坝的变化特性,对土工格栅和堆石料接触面特性进行了拉拔试验,发现接触面上的剪应力较大,且随上覆压力的增加而增加;试验拉拔位移主要为土工格栅的伸长量,接触面上的相对位移较小,因此加筋土石坝数值模拟应设置土工格栅和堆石料接触面变形协调,并将试验结果应用于加筋土石坝的数值模拟中,分析了土石坝加筋前后应力变形特性和动力响应的变化规律。结果表明,加筋对土石坝变形的抑制效果主要体现在地震工况下;加筋后坝体的地震永久变形有所减小,加筋对顺河向的地震永久变形抑制效果大于震陷;加筋后顺河向永久变形指向下游,最大震陷位于坝顶。

Experimental and Numerical Simulation of Geogrid Reinforced Earth Rockfilee Dam

In order to further understand the change characteristics of geogrid reinforced earth rockfill dam, the characteristics of contact surface between geogrid and rockfill were studied by pullout test. It was found that the shear stress on the contact surface is larger and increases with the increase of the overlying pressure; The tensile displacement of the test is mainly the elongation of the geogrid, and the relative displacement on the contact surface is small. Therefore, numerical simulation of reinforced earth rockfill dam should be set up deformation coordination between geogrids and rockfill materials. The experimental results were applied to the numerical simulation of reinforced earth rockfill dam. The stress and deformation characteristics and the dynamic response of earth rockfill dam were analyzed. The results show that the effect of reinforcement on the deformation of earth rock dam is mainly reflected in the earthquake condition. After reinforcement, the permanent deformation of the dam is reduced, and the effect of reinforcement to the permanent deformation of the river direction is greater than that of the earthquake. After the reinforcement, the permanent deformation is directed to the lower reaches, and the maximum seismic subsidence is located at the top of the dam.