摘要
为了研究盾构开挖面中心应力集中现象对侧穿的桥梁桩基的扰动,以广东省某大直径盾构隧道近距离侧穿既有桥梁桩基为工程背景,运用Midas有限元模拟分析施工过程中开挖面出现集中应力时对桥梁桩基竖向与水平位移影响,并通过线性回归方程预测开挖面允许出现的最大集中应力。结果表明:在泥水应力550 kPa,集中应力983 kPa情况下桩体最大水平位移达到6.87 mm,已超过预警值,需提前采取加固措施;线性回归分析得到在保证桩体水平位移符合规范条件下,开挖面允许最大集中应力为773 kPa。掘进压力主要使桩体产生水平方向上的挠曲变形并且在与隧道轴线同一埋深位置的桩体变形量最大,集中应力的出现使得桩体挠曲变形量增大。
In order to analyze the disturbance of the stress concentration phenomenon in the center of the shield excavation face on the side-crossing bridge pile foundation,a large-diameter shield tunnel in Guangdong Province was taken as the engineering background.The Midas finite element program was used to simulate and analyze the influence of the concentrated pressure on the vertical and horizontal displacement of the bridge pile foundation during the construction process,and the maximum allowable concentrated pressure of the excavation face was predicted by the linear regression equation.The results show that the excavation pressure mainly causes the pile body to produce the horizontal deflection deformation,and the deformation of the pile body at the same buried depth with the tunnel axis is the largest.The occurrence of concentrated pressure increases the deflection deformation of the pile body.Under the mud water pressure of 550 kPa and concentrated pressure of 983 kPa,the maximum horizontal displacement of the pile body reaches 6.87 mm,which has exceeded the warning value.Therefore,reinforcement measures shall be taken in advance.For this project,the linear regression analysis shows that the maximum allowable concentration pressure of the excavation surface is 773 kPa under the condition that the horizontal displacement of the pile conforms to the specification.
作者
李文杰
杨振兴
王江锋
杨杰
陈宏明
LI Wenjie;YANG Zhenxing;Wang Jiangfeng;YANG Jie;CHEN Hongming(College of Geosciences and Engineering,North China University of Water Resources and Electric Power,Zhengzhou,He′nan 450046,China;State Key Laboratory of Shield Machine and Boring Technology,Zhengzhou,He′nan 450001,China;China Railway Tunnel Group Co.,Ltd.,Guangzhou,Guangdong 511458,China;China Railway Tunnel Stock Co.,Ltd.,Zhengzhou,He′nan 450001,China;Chongqing Railway Group Co.,Ltd.,Chongqing 410700,China)
出处
《水利与建筑工程学报》
2024年第1期156-162,176,共8页
Journal of Water Resources and Architectural Engineering
基金
河南省科技攻关计划(212102310282)
中铁隧道科技开发计划(隧研合2022-03)。
关键词
盾构隧道
应力集中
侧穿桥桩
桩基位移
数值模拟
shield tunnel
pressure concentration
side-crossing the bridge pile
displacement of pile foundation
numerical simulation
