地震作用下土工格栅加筋挡土墙变形特性与筋材受力特征研究

Study on Seismic Deformation and Geo-grid Force of Geo-grid Reinforced Retaining Wall under Earthquake

土工格栅加筋挡土墙是一种柔性挡土结构物,在地震中会产生较大的变形。对土工构筑物安全起控制作用的是变形问题,为研究地震作用下模块式土工格栅加筋墙体的抗震变形特性,采用非线性动力有限差分法,分析土工格栅加筋长度和地震动强度这2个关键参数对加筋墙体地震变形特性和筋材受力特性的影响。研究结果表明,地震作用下的模块式土工格栅加筋墙体呈倾斜变形模式,墙顶残余变形最大;土工格栅加筋长度存在临界有效长度,取值在0.7 H～1.0 H之间为最佳;格栅受力沿着墙体深度先逐渐增加后又逐渐减小,最大格栅受力层在加筋体中下部,分布特征与作用在柔性挡土结构物上的土压力其分布规律基本相似。

Geo-grid reinforced retaining wall is a flexible retaining structure.It will undergo large deformation during earthquake.Deformation is a key problem for geo-structure safety.To study the seismic deformation of geo-grid reinforced retaining wall,non-linear finite difference method is applied to analyze the effect of seismic deformation and geo-grid force under different geo-grid length and earthquake excitation level.The calculation results show that the deformation of segmental geo-grid reinforced retaining wall has a tilting deformation mode and seismic residual deformation at top of the wall is the greatest.The geo-grid has a critical effective reinforced length and the value between 0.7 and 1.0 of wall height is the best.The geo-grid force gradually increases and then decreases from the top to the bottom of the wall and the greatest force exists in the lower part of wall.The distribution feature is similar to the distribution of earth pressure acting on the flexible retaining structure.