刚性桩复合地基离心试验插桩制模研究  

Study on the pile insertion and model preparation in centrifugal test of rigid pile composite foundation

作　　者：姜彦彬 丁元芳[3] 钱亚俊 倪政[1] 王艳芳 JIANG Yanbin;DING Yuanfang;QIAN Yajun;NI Zheng;WANG Yanfang(School of Architectural Engineering,Jinling Institute of Technology,Nanjing 211169,China;Key Laboratory of Reservoir and Dam Safety,Ministry of Water Resources,Nanjing 210029,China;Information Center of Hydrological Bureau,Songliao Water Resources Commission,Changchun 130021,China;Nanjing Hydraulic Research Institute,Nanjing 210029,China)

机构地区：[1]金陵科技学院建筑工程学院,江苏南京211169 [2]水利部水库大坝安全重点实验室,江苏南京210029 [3]松辽水利委员会水文局(信息中心),吉林长春130021 [4]南京水利科学研究院,江苏南京210029

出　　处：《水利水运工程学报》2023年第5期123-130,共8页Hydro-Science and Engineering

基　　金：国家自然科学基金青年科学基金项目(52208346);江苏省高等学校基础科学(自然科学)研究面上项目(22KJB560017);水利部水库大坝安全重点实验室开放基金(YK323008)。

摘　　要：土工离心模型试验是研究复合地基关键问题的前沿手段,饱和黏土工况下的刚性桩复合地基离心模型制作复杂,影响因素较多。基于多组刚性桩复合地基离心模型的制备过程分析,探讨了1g下插桩制模对离心模型地基抗剪强度的影响。试验结果表明:离心模型地基制样扰动与插桩方式相关,先引孔、后插桩有益于减少制样扰动。1g制模过程中,黏土模型地基的不排水抗剪强度有所损失,插桩制作扰动与1g下模型静置是导致饱和模型地基强度损失的主要原因,且复合地基上层软土抗剪强度的降低程度大于下部持力层。离心模型对比试验应充分考虑模型土样应力历史的相似性。研究提出了理想的刚性桩复合地基离心模型试验步骤,可为提升土工离心模型试验的精细化水平提供参考。Geotechnical centrifuge model test is an advanced technology to study the key issues of composite foundation.The centrifugal modelling of rigid pile composite foundation under saturated clay condition is complex and has numbers of influencing factors,which should be paid enough attention to.Based on the analysis of the preparation process of centrifuge model of several groups of rigid pile composite foundation,this paper discusses the influence of1g pile insertion modelling on the shear strength of the foundation model.It is shown that the disturbance of sample preparation of centrifugal model foundation is related to the way of pile insertion,and it is beneficial to reduce the disturbance of sample preparation to guide a hole before inserting the pile.The undrained shear strength of the clay model foundation will be weakened during the molding process under 1g.The comparative analysis shows that the disturbance of pile insertion and the model preparation under 1g are the main reasons for the strength loss of the saturated foundation model.The reduction of shear strength of upper soft soil of composite foundation is greater than that of the lower bearing layer.The similarity of stress history of the soil samples should be fully considered in the centrifugal model comparison test.An ideal centrifuge modelling procedure of rigid pile composite foundation is proposed,which provides an important reference for improving the refinement level of geotechnical centrifugal model test.

关 键 词：复合地基 离心模型试验 插桩 抗剪强度 模型制作 

分 类 号：TU472[建筑科学—结构工程]