雨水入渗对土工格栅-堆石界面剪切特性影响试验研究  

Experimental study on the influence of rainwater infiltration on the shear behavioursof geogrid-rockfill interface

作　　者：陈洪春 徐剑飞 徐祥 梁睿斌 段玉昌 洪磊 李明 CHEN Hongchun;XU Jianfei;XU Xiang;LIANG Ruibin;DUAN Yuchang;HONG Lei;LI Ming(Jiangsu Jurong Pumped Storage Co.,Ltd.,Jurong 212400,Jiangsu,China)

机构地区：[1]江苏句容抽水蓄能有限公司,江苏句容212400

出　　处：《水利水电技术（中英文）》2023年第S02期254-261,共8页Water Resources and Hydropower Engineering

基　　金：国家重点研发计划(2022YFE0105000);国家自然科学青年基金资助项目(52209160,52009036)。

摘　　要：为了解雨水入渗对格栅-堆石界面剪切特性的影响,利用自主研发的大型直剪仪,针对不同雨水入渗量下的格栅加筋堆石料和无格栅加筋堆石料开展了直剪试验,分析了雨水入渗对格栅加筋堆石料抗剪强度、剪切变形以及格栅加筋系数的影响,同时与无格栅加筋堆石料的试验结果进行对比。结果表明:随着雨水入渗量的增加,格栅表面摩擦系数降低,格栅加筋堆石料的抗剪强度呈明显的减小趋势,但对无格栅加筋堆石料抗剪强度的影响较小;当格栅加筋堆石料从干燥到完全饱和状态时,其内摩擦角从53.6°减小至50.4°,粘聚力从41.9 kPa减小至23.2 kPa;由于堆石颗粒受格栅网孔的嵌锁作用,格栅加筋堆石料竖向剪胀变形较加筋前有所减小,且雨水入渗堆竖向剪胀变形的影响较小;格栅加筋系数随着雨水入渗量的增加而减小,在竖向应力为25 kPa时,格栅加筋系数减小幅度较小,且均大于1.0,当竖向应力大于50 kPa后,格栅加筋系数减小至1.0以下。To investigate the influence of rainwater infiltration on the shear behaviours of geogrid-rockfill interface,the direct shear tests were carried out on rockfill materials with and without geogrid reinforced with different amounts of rainwater infiltration,by using a large direct shear apparatus which is developed independently.The influences of rainwater infiltration on the shear strength and shear deformation of geogrid reinforced rockfill,and the reinforcement coefficient were analyzed.In addition,the experimental result of the geogrid reinforced rockfill were compared with those of unreinforced.The result show that the friction coefficient of geogrid surface decreases with the increase of rainwater infiltration,which leads to the obvious decrease of the shear strength of grid reinforced rockfill.However,the influence of the rainwater infiltration is small for the unreinforced rockfill.As the geogrid reinforced rockfill changes from the dry condition to the fully saturated condition,the internal friction angle of the grid reinforced rockfill decreases from 53.6°to 50.4°,and the cohesion decreases from 41.9kPa to 23.2kPa.For the interlocking effect of geogrid mesh,the vertical dilatation deformation of the rockfill is reduced after grid reinforcement.Besides,the rainwater infiltration has little influence on the vertical dilatation deformation of the grid reinforced rockfill.The reinforcement coefficient decreases with the increase of rainwater infiltration,when vertical stress is greater than 50kPa,the reinforcement coefficient decreases to the value below 1.0.However,when the vertical stress is 25kPa,the decrease of reinforcement coefficient with rainwater infiltration is slightly,and the reinforcement coefficient is still greater than 1.0 after fully saturation.

关 键 词：土工格栅加筋 堆石料 雨水入渗 大型直剪试验 剪切特性 

分 类 号：TU[建筑科学]