基于细砂地层中土压平衡盾构施工对桩基的多因素影响分析  

Multi-factor influence analysis of earth pressure balance shield construction on pile foundation in fine sand strata

作　　者：张昕 李志朋 王晓睿 于怀昌 张幸举 Zhang Xin;Li Zhipeng;Wang Xiaorui;Yu Huaichang;Zhang Xingju(School of Earth Science and Engineering,North China University of Water Resources and Electricity University,Zhengzhou 450045,China;China Railway 11th Bureau Group Urban Rail Engineering Co.,Ltd.,Wuhan 430074,China)

机构地区：[1]华北水利水电大学地球科学与工程学院,郑州450045 [2]中铁十一局集团城市轨道工程有限公司,武汉430074

出　　处：《工程勘察》2023年第7期7-12,共6页Geotechnical Investigation & Surveying

基　　金：国家自然科学基金青年项目(51309100)。

摘　　要：郑州地铁12号线胡庄站—龙西湖西站区间采用土压平衡盾构机进行掘进施工,该区间盾构隧道多处侧穿桥梁桩基施工,为了研究盾构施工过程中对桩基的影响规律,采用数值模拟的方法,建立隧—桩相互作用三维有限元模型,模型中考虑了桩长、桩径、桩隧间距、摩擦桩与端承桩以及盾构下穿桩基等因素。研究结果表明:盾构施工对不同埋深的桩的影响规律不同,当桩端位于隧道底部以上时,桩的横向位移呈直线型,当桩端位于隧道底部以下时,桩的横向位移呈现非线性,桩顶沉降随桩埋深的增加而逐渐减小;随着桩隧间距的增加,桩体的横向位移和桩顶沉降都逐渐减小;适度增大桩径可以减小桩的横向位移和桩顶沉降;盾构隧道施工使端承桩产生的位移要比摩擦桩小;盾构下穿桩基施工时,桩基会产生较大的沉降,轴线位移呈现直线型。Earth pressure balance shielding was used in the tunnel construction from Huzhuang Station to Longxi Lake West Station of Zhengzhou Metro Line 12.The tunnel crosses the high-speed railway bridge piles in several places.In order to study the tunneling influence on piles,a three-dimensional finite element model is established to simulate the tunnel-pile interaction.The factors including pile length,diameter,pile-tunnel spacing,friction pile and end-bearing pile,and shield tunneling under piles etc.are considered in the model.The study shows that the impact of shield construction on different buried piles is different.When the pile bottom is located above the tunnel base,the horizontal displacement of the pile is straight;when the pile bottom is below the tunnel base,the horizontal displacement of the pile is nonlinear,the pile top settlement gradually decreases with the increase of the pile buried deep;with the spacing between pile and tunnel increases,the pile shaft horizontal displacement and the pile top settlement decreases gradually;increasing the pile diameter will reduce the horizontal displacement and top settlement.The displacement of the end bearing piles caused by shield tunneling is less than that of the friction piles;when the shield tunneling under the pile foundation,the foundation will generate a large settlement,the axis displacement presents a straight line.

关 键 词：盾构隧道 单桩 位移 有限元分析 

分 类 号：TU473[建筑科学—结构工程]