Internal Force Analysis Of Shield Tunnel Segments And Application Development Of Finite Element Software

In recent years,with the development of tunnel engineering in the world,the technology related to tunnel engineering has been improved.The design method and computing technology of tunnel have been developed and credited continuously.In order to study the mechanical properties of concrete segment joint,elastic-plastic model and plane section deformation assumption are applied,the calculation model of concrete segment joint is presented,and the analytical expression of ultimate bending moment of segment joint is derived.And the influence of axial force on ultimate bending moment is analyzed.Research shows that with the increase of axial force,ultimate bending moment of segment joint increases.In order to verify the model,finite element model of segment joint is established.In order to study the influence factors of internal force of segments,the influence of tunnel depth,tunnel diameter and Poisson’s ratio on internal force of segments is analyzed.Research shows that with the increase of buried depth of tunnel,the internal force of segments increases linearly.The influence of depth on axial force is the largest.With the increase of diameter,axial force and bending moment increase.In the process of changing from small diameter to large diameter,shear force increases first and then decreases.With the increase of Poisson’s ratio of soil layer,internal force of segments shows a decreasing trend.The Poisson’s ratio of soil layer has great influence on internal force of segments.In order to study the seismic performance of segments,the seismic performance of shield tunnel in Qiongzhou strait is analyzed by using El Centro waves.And the internal force increment of segments is analyzed.Research shows that internal force of segments increases under the horizontal seismic loads.The shearing force increases by 5.13%,bending moment increases by 4.67%,and axial force increases by 0.87%.So,in the seismic design of segments,we should focus on improving the shear performance and bending performance of tunnel segments.In order to improve the efficiency of segment design and analysis,application development of ANSYS is applied.The parametric analysis of mechanical properties of segments is realized by combining VB and APDL.This system includes internal force analysis,reinforcement calculation and seismic performance analysis.This method reduces the difficulty of models design,and provides a new idea for complex model design.