竖向循环荷载作用下粉土地基开口管桩承载力特性模型试验研究  

Model test on mechanical characteristics of open-end pipe pile in silty soil under vertical cyclic loading

作　　者：王清明 侯伟 刘俊伟[2] 提衍征 杜相波 Wang Qingming;Hou Wei;Liu Junwei;Ti Yanzheng;Du Xiangbo(Shandong High-Speed Infrastructure Construction Co.,Ltd.,Jinan 250014;Qingdao University of Technology,Qingdao 266520;Shandong High-Speed Construction Management Group Co.,Ltd.,Jinan 251499;Shandong High-Speed Engineering Test Co.,Ltd.,Jinan 250002)

机构地区：[1]山东高速基础设施建设有限公司,济南250014 [2]青岛理工大学土木工程学院,山东青岛266520 [3]山东高速建设管理集团有限公司,济南251499 [4]山东高速工程检测有限公司,济南250002

出　　处：《工程勘察》2024年第12期20-27,74,共9页Geotechnical Investigation & Surveying

基　　金：山东省优秀青年基金(ZR2021YQ31);泰山学者工程专项经费资助(tsqn202211176);国家自然科学基金面上项目(42277135)。

摘　　要：竖向循环荷载作用下管桩承载力特性的演化规律对交通基础设施的正常使用具有重要意义。研制了新型双壁开口管桩,该新型桩基的特点是可以单独监测管桩内外侧的受力。利用双壁管桩开展了循环荷载作用下粉土地基中开口管桩承载力特性的模型试验,探究了竖向循环荷载的幅值和频率对开口管桩位移、沉降和管桩内外壁轴力的变化规律。得到如下结论:循环荷载加载初期,管桩产生明显的累积沉降,随着循环次数的增加沉降逐渐趋于稳定;当桩顶荷载幅值由10%极限承载力增大一倍时,开口管桩的累积沉降增大约65%;随着加载频率增加,开口管桩的累积沉降呈线性增长;土塞的约束会导致管桩内壁产生轴力,且随着循环次数增加管桩内壁轴力逐渐增大,但内壁轴力的大小仅为外壁轴力的23%。The evolutionary pattern of bearing capacity of pipe pile under vertical cyclic loading is important to ensure the normal use of transportation infrastructure.A double-walled open-ended pipe pile has been innovated to monitor the axial load on inner and outer side wall of the pile independently.A series of model tests were conducted of this newly developed pipe pile to analyze the mechanical characteristics of open-ended pipe piles in silty soil under cyclic loading,including to study the trends in amplitude and frequency of vertical cyclic loading concerning the displacement and settlement of open-ended pipe piles,as well as the axial force distribution along the inner and outer wall of the piles.The investigation reveals that during the initial phase of cyclic loading,the cumulative settlement of the pile is conspicuous and becoming stable with the loading cycle increases;when the force on the pile top doubles from 10%of the ultimate bearing capacity,the cumulative settlement of the open-ended pile increases approximately 65%;cumulative settlement exhibits a mostly linear correlation with the increment of loading frequency,the axial force is generated along the inner wall of the pipe pile due to the soil plug effect,and force increases with the loading cycle,the force in the inner wall is about 23%of the axial force in the outer wall.

关 键 词：循环荷载 开口管桩 粉土地基 承载力特性 模型试验 

分 类 号：TU473.11[建筑科学—结构工程]