非等桩径荤素桩组合咬合桩受力计算模型研究  

Research on the force calculation model of the bored occluding pile composed of unequal diameter reinforced concrete piles and plain piles

作　　者：洪源 彭正坤[1] 任晨灏 曾习凡 梅东 李繁 HONG Yuan;PENG Zheng-kun;REN Chen-hao;ZENG Xi-fan;MEI Dong;LI Fan(The Eighth Sinohydro Bureau Co.,Ltd.,Changsha 410004,China;School of Civil Engineering,Central South University,Changsha 410075,China)

机构地区：[1]中国水利水电第八工程局有限公司,湖南长沙410004 [2]中南大学土木工程学院,湖南长沙410075

出　　处：《交通科学与工程》2021年第1期75-81,共7页Journal of Transport Science and Engineering

基　　金：国家自然科学基金资助项目(50908234);湖南省自然科学基金项目(2020JJ4743)。

摘　　要：针对咬合桩等效成地下连续墙的理论计算模型中的不足,本研究考虑钻孔咬合桩中荤素桩之间桩径相对大小的影响及素混凝土桩的刚度折减效应,推导出修正后的等效刚度的咬合桩受力与形变理论计算模型。依托深圳市城市轨道交通12号线太子湾站主体围护结构咬合桩工程,采用Midas/GTS NX有限元软件建立了数值模拟,分析了基坑开挖全过程围护结构的受力机理与变形规律,验证理论计算模型。研究结果表明:随着基坑开挖,围护结构最大水平位移最终收敛于10 mm左右。开挖工况下,围护结构的内力与变形增长较快,尤其第三层土开挖完成后结构内力迅速增长。验证了该理论模型能够有效预测基坑施工过程中钻孔咬合桩的内力与位移发展规律,可为围护结构的合理设计与安全施工提供理论指导。Aiming at the shortcomings in the current theoretical calculation model of occluding piles equivalent to underground continuous walls,this paper considered the influence of the relative size of the pile diameter between the reinforced concrete piles and the plain concrete piles in the bored occluding piles and the stiffness reduction effect of the plain concrete piles.The corrected equivalent rigidity occluding pile force and deformation theoretical calculation model was derived.At the same time,relying on the occluding pile project of the main enclosure structure of the Taiziwan Station of Shenzhen Urban Rail Transit Line 12,the finite element software(Midas/GTS NX)was used to establish a numerical simulation test to analyze the force mechanism and the deformation law of the enclosure structure during the whole process of excavation of the foundation pit.The deformation law verifies the accuracy of the theoretical calculation model.The analysis results of the theoretical model and the numerical model were combined to point out the structural weaknesses in the bored occluding pile engineering example,and suitable measures were given.The research results show that with the excavation of the foundation pit,the maximum horizontal displacement of the enclosure structure finally converges to about 10 mm.Under the excavation conditions,the internal force and deformation of the enclosure structure increase rapidly,especially after the third layer of soil is excavated.The theoretical model in this paper can effectively predict the internal force and displacement development law of the bored occluding pile during the construction of the foundation pit,and then guide the rational design and safe construction of the enclosure structure.

关 键 词：钻孔咬合桩 等效刚度法 数值模拟 受力机理 变形规律 

分 类 号：TU753.3[建筑科学—建筑技术科学]