三向土工格栅筋-土界面特性拉拔试验研究

发布时间：2018-04-03 05:12

本文选题：三向土工格栅　切入点：拉拔试验　出处：《岩土力学》2017年02期

【摘要】：现有关于格栅与土的筋-土界面特性研究多以单、双向格栅为研究对象,而对三向土工格栅筋-土界面特性开展的试验研究较少。以三向土工格栅为研究对象并考虑0°和90°两种拉拔方向的影响(记为TX_0工况和TX_90工况),开展了一系列室内拉拔试验,通过对三向土工格栅沿拉拔方向4个断面的位移进行量测,分析了格栅拉伸应变、筋-土相对位移、界面摩阻力分布及格栅变形与破坏模式,并分别从峰值剪切强度和残余剪切强度两个方面对筋-土界面强度参数和表观摩擦系数的变化规律进行了探讨。研究结果表明:由于平面外挠曲变形的影响,TX_0工况下横肋的嵌锁作用随法向应力增大而增强,从而使TX_0工况的拉拔性能逐渐优于TX_90工况;拉拔过程中,筋-土界面摩阻力的发挥是一个渐进的过程,其分布形式不断发生调整,筋-土界面呈弹塑性-软化特征;TX_0工况的筋-土界面摩擦角显著大于TX_90工况,黏聚力则刚好相反,法向应力较高时TX_0工况的筋-土界面强度更高,更有利于材料性能的发挥。
[Abstract]:Most of the existing studies on the geogrid and soil reinforced soil interface characteristics are focused on the single and bidirectional grille, but few experimental studies have been carried out on the three-dimensional geogrid geogrid geogrid interface characteristics.Taking the three-dimensional geogrid as the research object and considering the effects of the drawing directions of 0 掳and 90 掳(described as TX_0 and TX_90 conditions), a series of indoor drawing tests were carried out, and the displacement of four sections along the drawing direction of the three-dimensional geogrid was measured.The tensile strain of grid, the relative displacement between reinforcement and soil, the distribution of interfacial friction, the deformation and failure mode of grid are analyzed.The variation of the interface strength parameters and the apparent friction coefficient are discussed from the peak shear strength and the residual shear strength respectively.The results show that due to the influence of out-of-plane flexural deformation, the interlocking effect of transverse ribs increases with the increase of normal stress, which makes the drawing performance of TX_0 gradually better than that of TX_90.The exertion of frictional resistance at the interface between reinforcement and soil is a gradual process, and its distribution forms are adjusted constantly. The friction angle of the interface between the reinforcement and soil is obviously larger than that in the TX_90 condition, and the cohesive force is just the opposite at the condition of TX0.When the normal stress is high, the strength of the interface between reinforcement and soil is higher under the condition of TX_0, which is more favorable to the performance of the material.
【作者单位】：华中科技大学岩土与地下工程研究所;
【基金】：国家自然科学基金项目(No.51278216) 湖北省自然科学基金项目(No.2013CFB180) 华中科技大学研究生创新创业基金项目(No.HF-11-13-2013)~~
【分类号】：TU472

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