水平地震作用下双级加筋土挡墙格栅应变及破裂面分析

基于大型振动台模型试验,研究水平地震荷载作用下双级土工格栅加筋土挡墙的格栅应变和潜在破裂面规律。用福建砂作为回填砂、混凝土砌块作为挡墙和土工格栅作为筋材构成了试验模型。模型高度1.8 m。输入地震波为卧龙波和EL-Centro波,共9个试验工况。试验结果表明,随着峰值加速度增大,应变值增大,且应变最大值点向土体内部扩展。潜在破裂面随峰值加速度增加逐渐向土体内部扩展。综合已有破裂面计算方法,提出了考虑平台宽度的双级折线型破裂面模型,模型可为双级加筋土挡墙设计计算提供参考。

Geogrid strain and failure surface of two-stage reinforced soil retaining wall under horizontal seismic loading

Based on the large-scale shaking table model tests, the geogrid strain and failure surface of two-stage reinforced soil-retaining wall under horizontal seismic loading are studied. The experimental model is made of backfill, retaining wall and geosynthetics, where the backfill is standard soil, the retaining wall is concrete blocks and the geosynthetics is geogrid. The model height is 1.8 m. The input seismic waves are Wolong waves and EL-Centro waves. The test results show that with the increase of the peak acceleration, the strain value increases, and the maximum strain point extends to the soil interior. With the increase of the peak acceleration, the potential rupture surface gradually extends to the soil interior. Based on the existing methods for calculating the fracture surface, a double-broken line model considering the width of the offset is proposed. The proposed model can be used as a reference for the design of the two-stage reinforced soil retaining wall.