摩擦桩-砂土接触面剪切特性可视化试验研究  

Visualized test study on shear characteristics of friction pile-sand-soil interface

作　　者：金佳旭[1] 袁士豪 梁冰[1] 李世旺[1,2] 刘家顺 周克林[1,3] JIN Jiaxu;YUAN Shihao;LIANG Bing;LI Shiwang;LIU Jiashun;ZHOU Kelin(College of Civil Engineering,Liaoning Technical University,Fuxin 123000,Liaoning,China;China Construction Land Sea Investment Development Company,Tianjin 30000,China;Zunyi Qianbei Highway Construction Development Investment Co.Lid,Zunyi 563000,Guizhou,China)

机构地区：[1]辽宁工程技术大学,辽宁阜新123000 [2]中建陆海投资发展公司,天津300000 [3]遵义市黔北公路建设开发投资有限责任公司,贵州遵义563000

出　　处：《实验力学》2022年第4期551-560,共10页Journal of Experimental Mechanics

基　　金：国家自然基金(No.51974145,No.51974186);岩土及地下工程教育部重点实验室(同济大学)开放课题(KLE-TJGE-B2001);城市地下空间工程北京市重点实验室开放基金(中央高校基本科研业务费专项资金(FRF-BD-19-004A));国家重点研发计划(2018YFC0604705);辽宁工程技术大学学科创新团队项目(LNTU20TD-05,LNTU20TD-17)。

摘　　要：桩-土界面剪切特性严重影响桩基侧摩阻力发挥,常造成桩基失稳等工程灾害。为研究砂土地区摩擦作用对桩-土界面剪切特性的影响,通过自主设计的大型可视化剪切试验,得到了粗糙度对剪切特性及剪切带颗粒变化规律的影响。试验结果表明:随着粗糙度的增加,抗剪强度、摩擦角、剪切刚度和残余强度等参数均显著增加,剪切模量最大增加幅度达49.49%;黏聚力先增加,当粗糙度超过0.393mm时,便开始减小;粗糙度和法向应力均是剪切带厚度的影响因素之一;接触面临界相对粗糙度为0.393mm。上述研究成果对提升砂土地区摩擦桩设计可靠性及完善桩土相互作用宏细观机理具有一定意义。The shear characteristics of the pile-soil interface seriously affect the side friction of the pile foundation,and often cause engineering disasters such as the instability of the pile foundation.In order to study the influence of friction in sandy soil area on the shear characteristics of the pile-soil interface,a self-designed visual experiment on the shear characteristics of the sand-concrete interface under different roughness conditions was carried out.The self-designed visual experiments on the shear characteristics of the sand-concrete interface under different roughness conditions were carried out,and the influence of the roughness on the sand-concrete shear characteristic parameters and the particle change law of the shear zone was studied.The test results show that with the roughness increases,all of the parameters,such as shear strength,friction angle,shear stiffness and residual strength,increase significantly,with the largest increase of 49.49%;cohesion first increases,and when the roughness exceeds 0.393 mm,it begins to decrease;roughness and normal stress are one of the factors to affect the thickness of the shear zone;and the critical relative roughness of the contact surface is 0.393 mm.The research results have a certain significance for improving the design reliability of friction piles in sandy soil areas and improving the macro and mesoscopic mechanism of pile-soil interaction.

关 键 词：基础工程 桩土接触面 剪切特性 粗糙度 抗剪强度 剪切带 

分 类 号：TU560[建筑科学—建筑技术科学]