柔性网面土工格栅加筋土挡墙工程特性

Engineering behaviors of geogrid reinforced earth retaining wall of flexible surface

为研究柔性网面土工格栅加筋土挡墙的工程特性,分析其工作机理,进行室内试验。试验测试墙背侧向土压力、垂直土压力、筋带变形以及面墙变形情况,研究挡墙侧向土压力和垂直土压力分布、筋带应变分布、挡墙潜在破裂面以及面墙变形规律等。研究结果表明:侧向土压力沿墙高呈非线性分布,每层的侧向土压力随施加荷载增大而呈线性增大,但其增大速率远小于理论值增大速率;增大加卸载循环次数也会使得残余侧向土压力增大;垂直土压力沿筋材长度方向呈均匀分布,挡墙第1层的垂直土压力略小于理论值;施加荷载会使得拉筋应变分布发生变化,筋带在试验荷载作用下可以满足强度要求;由广义库仑法得到的潜在破裂面与筋材最大应变位置较吻合;面墙最大侧向变形发生在第3层和第4层,面墙中间位置有鼓出现象。

Based on the laboratory test, engineering behaviors of geogrid reinforced earth retaining wall were studied. Lateral and vertical earth pressure, deformation of reinforcement and wall face were tested. The distributions of vertical and lateral earth pressure, the strain of reinforcement and the lateral deformation behavior of wall face were analyzed. The results show that lateral earth pressure distributes non-linearly along wall back. Lateral earth pressure in each layer increases linearly with the increase of the imposed load, but the increasing rate is smaller than that of the theoretical value. Cycles of load and unload make residual lateral earth pressure increase. Vertical earth pressure shows uniform distribution along reinforcement, and it is smaller than theoretical value in the first layer of retaining wall. With the increase of imposed load, the distribution of strain along the reinforcement changes, and the reinforcement can meet strength requirement under test load.The potential failure surface of retaining wall determined by generalized Coulomb theory is quite consistent with the position of maximum strain of reinforcements. The maximum lateral deformation of wall face occurs in the third layer and the fourth layer of retaining wall, which leads to bulging phenomenon in the middle of wall face.