不同台阶断面对路基拼接变形影响的数值分析

Numerical Analysis of Impact of Different Sidestep Section on Subgrade Connecting in High-Speed Railway

通过数值模拟对不同台阶断面在高速铁路路基拼接中的变形影响进行了研究。结果表明,路基高度相同的情况下,新老路基搭接处、老路基面下的差异沉降随一次性开挖台阶断面的尺寸增大而增大,并且后期每一施工步引起的变形增量也增大。此外,路基拼接施工引起的最大沉降点位于新老路基搭接处。由于路基土体固结已基本完成,故路基的工后沉降受台阶断面尺寸的影响不大。因此为减少老路基台阶开挖对既有线行车安全的影响,应控制开挖台阶断面的尺寸。对不同台阶断面方案比选的数值模拟,将对控制高速铁路路基拼接的不均匀沉降有较好的指导作用。

According to results of numerical simulation for three kinds of sidestep section of subgrade connecting in high - speed railway, displacements distribution of subgrade sections are obtained. It shows that minishing the sidestep section of subgrade can effectively enhance snhgrade integration property, at the same height of snhgrade, which observably results in reducing differentia deformations of the connection between the new subgrade and the old sub- grade surface and depresses the velocity of deformation increment. Moreover, the point of maxmium deformation following subgrade constructing is located in subgrade connection. The settlement after the consolidation of soil as subgrade has been basically completed, so three kinds of sidestep section of subgrade have little effect on it. Therefore, to reduce the infection of excavating sidestep to existing lines, the sidestep section size of subgrade excavation should pay more attention to control. It will be instructive to control differentia deformation for the connecting subgrade projects in high -speed railway.