条基下格栅长度及纵横肋变化的加筋挡墙试验研究

Experimental study on reinforced earth retaining wall with different geogrid length and number of transverse ribs under strip foundation

为研究格栅长度及纵横肋数量变化对加筋土挡土墙承载性能的影响,以自行设计的尺寸为1 500 mm×1 000 mm×1 300 mm(长×宽×高)的模型箱开展加筋挡墙室内模型试验,分析在静载作用下格栅长度及格栅横肋数量变化对加筋土挡土墙的加载板沉降、面板水平位移及竖向附加应力等参数的变化规律。试验结果表明:静荷载下,改变加筋土挡墙内部的格栅长度及纵横肋数量,均降低了挡墙结构的极限承载力;格栅长度越小,减去格栅纵横肋数量越多,加载板沉降越大;静载作用下加筋土挡墙破坏大多数为局部破坏,随格栅长度及纵横肋数量逐渐减少,加筋土挡墙破坏模式向整体破坏趋势发展。土工格栅对上部土体传来的附加应力起到较大的扩散衰减作用,减少土工格栅长度及纵横肋数量,均改变了土体内部的应力场,使竖向附加应力传递到更深的土体中,降低了挡土墙的承载性能。

In order to study the influence of geogrid length and number of longitudinal and transverse ribs on the bearing capacity of reinforced earth retaining walls,an indoor reinforced earth retaining wall model was designed in the model box of 1 500 mm×1 000 mm×1 300 mm(length×width×height).Experiments were conducted to analyze the variation of the parameters such as the settlement of the loading plate,the horizontal displacement of the panel and the vertical additional stress of the reinforced earth retaining wall under the static load.The experimental results show that under the static load,changing the geogrid length and the number of vertical and horizontal ribs inside the reinforced soil retaining wall can reduce the ultimate bearing capacity of the retaining wall;the smaller the geogrid length is,the larger the settlement of the loading plate will be;the less the number of geogrid ribs is,the larger the settlement of the loading plate will be.Most of the reinforced retaining wall under the static load suffers local failure.With the decrease of the geogrid length and the number of longitudinal and transverse ribs,the overall failure of the reinforced retaining tends to occur.The geogrid has an obvious diffusion and attenuation effect on the additional stress of the upper soil.By reducing the length of geogrid or the number of longitudinal and horizontal ribs,the internal stress field of soil changes,the additional vertical stress is transferred to deeper soil,and the bearing capacity of the retaining wall is reduced.