土工格栅加筋膨胀土拉拔试验研究

发布时间：2018-04-14 21:52

本文选题：土工格栅 + 膨胀土　；参考：《岩土力学》2015年S1期

【摘要】：土工格栅加筋技术对膨胀土地质灾害的防治具有特殊效果,但目前对土工格栅与膨胀土界面特性的研究不足。采用南水北调中线工程新乡段的膨胀性泥灰岩风化土作填料,塑料单向拉伸土工格栅作为加筋体,在叠环式剪切试验机上通过施加不同的竖向荷载对其界面特性进行了拉拔试验研究。研究结果表明,土工格栅在膨胀土中的拔出过程主要经过3个阶段,分别是界面静摩擦力阶段、渐进剪切阶段和整体运动阶段,各阶段受力特性有明显差异;随着法向应力的增大,静摩擦力在界面抗剪强度比值呈对数级增大,从50 k Pa时0.20增大至400 k Pa时0.57,极限值可达到0.75;对挡土墙、高边坡等加筋设计中应考虑最大静摩擦力所占比重,在格栅的不同竖向高度处所受垂直应力不同,分段设计更加合理。
[Abstract]:Geogrid reinforcement technology has a special effect on the prevention and treatment of geological hazards of expansive soil, but the research on the interface characteristics between geogrid and expansive soil is insufficient at present.The expansive marl weathered soil of Xinxiang section of South-to-North Water transfer Project was used as filler, and the plastic uniaxial tensile geogrid was used as reinforced body.In this paper, the pull-out test was carried out on the superimposed annular shear tester by applying different vertical loads.The results show that the pull-out process of geogrid in expansive soil mainly goes through three stages, namely, interfacial static friction stage, progressive shear stage and whole motion stage.With the increase of normal stress, the shear strength ratio of static friction increases logarithmic, from 0.20 at 50 KPA to 0.57 at 400 KPA, and the limit value can reach 0.75.The proportion of maximum static friction should be taken into account in the design of high slope and the vertical stress at different vertical height of the grille is different and the sectional design is more reasonable.
【作者单位】：上海地矿工程勘察有限公司;
【基金】：国家科技支撑计划“膨胀土地段渠道破坏机制及处理技术研究”(No.2006BAB04A10)
【分类号】：TU443

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