沉管隧道钢鼻托梁承载力数值模拟分析

Numerical Simulation Analysis for Load Bearing Capacity of Steel Nose Pads Beam of Immersed Tunnel

据现有文献,钢鼻托梁为首次在沉管隧道工程中应用,现阶段其结构设计为经验性预估得来,且上、下两个鼻托梁对接过程中受到导向装置传递的竖向作用力,因此有必要对钢鼻托梁在竖向荷载作用下的承载力进行三维精细化数值模拟分析,以掌握其极限承载力和刚度情况。本文经过数值模拟分析,得到了模型在竖向荷载作用下的荷载-位移曲线、极限承载力、最大应力和位移发生的位置,得出鼻托梁为受剪为主的构件,其刚度较钢剪力键大,存在剪力键先于鼻托梁翘曲和破坏的风险等结论,本文研究为钢鼻托梁在工程应用中推广和改进提供有益参考。

According to the existing literatures,steel nose pads beam is used for the first time in the immersed tube tunnel project.At the present stage,the structural design of steel nose pads beam depends on empirical estimates.And the two upper and lower beams sustain vertical forces which are transferred by guide apparatus. So it is of great significance to make numerical simulation of three-dimensional fine model to obtain the bearing capacity and stiffness of the beam under vertical load. Based on the method of numerical simulation,a series of conclusions are obtained.Load-displacement curve,ultimate bearing capacity,and location of the maximum stress and displacement of the model under vertical load are acquired. Nose pads beam is a component who mainly resists shear force. The stiffness of the nose pads beam is larger than that of the steel shear key. And it is possible that the warping deformation and damage of the steel shear key may occur before that of the nose pads beam. This study could provide reference to the application and improving of the steel nose pads beam in practical engineering.