| 土工格栅加筋膨胀土拉拔试验研究 |
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| 引用本文： | 蔡剑韬.土工格栅加筋膨胀土拉拔试验研究[J].岩土力学,2015,36(Z1):204-208. |
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| 作者姓名： | 蔡剑韬 |
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| 作者单位： | 上海地矿工程勘察有限公司，上海200072 |
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| 基金项目： | 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） |
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| 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 kPa时0.20增大至400 kPa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。
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| 关 键 词： | 土工格栅 膨胀土 拉拔试验 界面特性 |
| 收稿时间： | 2015-03-09 |
Pull-out test on interface behavior between expansive soils and geogrids |
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| CAI Jian-tao.Pull-out test on interface behavior between expansive soils and geogrids[J].Rock and Soil Mechanics,2015,36(Z1):204-208. |
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| Authors: | CAI Jian-tao |
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| Institution: | Shanghai Geological & Mineral Engineering Investigation Co., Ltd., Shanghai 200072, China |
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| Abstract: | Reinforcement technology by geogrids has special effect for controlling geo-hazards occurred in expansive soils. But at present the research on the characteristics of interface between geogrids and expansive soils is insufficient; with laminated shear test apparatus, a series of pull-out tests is carried out to study the interaction between plastic uniaxial geogrid and expansive soils under different vertical loads. The soils are taken from the weathered expansive marlite in Xinxiang, the middle route of the South-to-North Water Transfer Project. The research results show that: the pull-out process of geogrid from expansive soils falls into three main stages, i.e. the interfacial static friction stage, progressive shear stage and the overall motion stage. There is obvious difference on the stress characteristics in each stage. As the normal stress increases, the ratio of the static friction to the interfacial shear strength shows a logarithmic increase, is from 0.20 at 50 kPa to 0.57 at 400 kPa; and its extreme value can reach 0.75. When adopting geogrid to reinforce retaining wall and high slope, the maximum static friction proportion should be considered; there is different vertical stress at vertical height of geogrid; sectional design is more reasonable. |
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| Keywords: | geogrid expansive soils pull-out test interface behavior |
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