In order to analyze the disturbance of the stress concentration phenomenon in the center of the shield excava-tion 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 con-centrated 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 occur-rence 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.
关键词
盾构隧道/应力集中/侧穿桥桩/桩基位移/数值模拟
Key words
shield tunnel/pressure concentration/side-crossing the bridge pile/displacement of pile founda-tion/numerical simulation
维普
万方数据