振冲碎石桩抗剪强度特性综合试验研究  

Comprehensive experimental study on the shear strength characteristics of vibroflotation gravel pile

作　　者：夏海 丁刚 熊诗湖[3] XIA Hai;DING Gang;XIONG Shihu(Shenzhen Raw Water Co.,Ltd.,Shenzhen 518000,Guangdong,China;Changjiang Design Group Co.,Ltd.,Wuhan 430010,Hubei,China;Key Laboratory of Geotechnical Mechanics and Engineering of the Ministry of Water Resources,Changjiang River Scientific Research Institute,Wuhan 430010,Hubei,China)

机构地区：[1]深圳市原水有限公司,广东深圳518000 [2]长江设计集团有限公司,湖北武汉430010 [3]长江科学院水利部岩土力学与工程重点实验室,湖北武汉430010

出　　处：《地基处理》2024年第6期589-594,共6页Journal of Ground Improvement

基　　金：国家自然科学基金资助项目(42277186)。

摘　　要：某三峡库岸整治工程中,针对库水冲积形成的淤泥质粉质黏土库岸,采用振冲碎石桩作为阻滑桩。碎石桩抗剪强度参数是施工设计与库岸稳定分析所需的基础参数。为研究碎石桩抗剪强度特性,确定其抗剪强度参数,开展了桩体大型原位直剪、碎石桩填料大型室内叠环剪和三轴压缩试验。不同试验方法的内摩擦角范围值为31.4°~33.0°,偏差系数为0.02,黏聚力范围值为17~73 kPa,偏差系数为0.69。探讨了不同试验方法的工程适宜性,认为剪切面下盘桩体掩埋于地基土的原位直剪试验条件与碎石桩工程条件基本一致。按不同方法试验值的最小值提出振冲碎石桩抗剪强度参数试验建议值:内摩擦角φ=31.4°、黏聚力c=17 kPa。In a remediation project of Three Gorges reservoir bank,vibroflotation gravel piles are used as anti-sliding piles for the mucky silty clay bank formed by reservoir water alluvial.The shear strength parameters of the gravel piles are basic parameters for construction design and bank stability analysis.In order to study the shear strength characteristics of the piles and determine its shear strength parameters,large-scale in-situ direct shear test of piles,large-scale laboratory frame-stacked ring shear test and triaxial compression test on the gravel pile fillers were carried out.For the internal friction angle of different test methods,the value ranges from 31.4°to 33.0°,and the deviation coefficient is 0.02.For the cohesion of different test methods,the value ranges from 17 kPa to 73 kPa,and the deviation coefficient is 0.69.The engineering suitability of different test methods was discussed and it was concluded that the conditions of in-situ direct shear test with the pile section below the shear plane buried in the foundation soil are basically consistent with the engineering conditions of the gravel piles.According to the minimum values of all kinds of tests,the recommended values of shear strength parameters of vibroflotation gravel pile are put forwardd as follows:The internal friction angle is 31.4°and the cohesion is 17 kPa.

关 键 词：原位测试 地基 振冲碎石桩 抗剪强度参数 叠环剪 三轴压缩试验 

分 类 号：TU41[建筑科学—岩土工程]