钢弹簧浮置板轨道与隧道底板相互作用数值模拟

Numerical Simulation for the Interaction between Steel Spring Floating Slab Track and Tunnel Floor

针对城市轨道交通穿越施工引起的轨道结构与隧道底板脱空的现象,采用ANSYS建立钢轨-钢弹簧浮置板道床-隧道底板的相互作用模型。考虑隧道底板变形方式、隧道底板最大变形值、Peck曲线沉降槽宽度、浮置板变形缝等影响因素,通过数值模拟计算轨道结构变形和内力、浮置板与隧道底板的脱空量和脱空范围,得出轨道结构与隧道结构相互作用的一般规律。计算结果表明:浮置板与隧道底板之间连接力弱,隧道底板发生不均匀变形时可能产生脱空;浮置板自身较大的刚度是其与隧道底板产生差异变形的主要原因,钢轨并不能对浮置板产生有效的约束;轨道与隧道结构的差异变形随隧道底板变形值的增大而增大,随沉降槽宽度的增大而减小;模型能够较全面地分析轨道与隧道结构相互作用问题,为计算穿越施工引起的既有轨道结构的变形、内力及其与隧道底板的脱空提供有效方法。

Aiming at the detachment between the track structure and the tunnel floor due to urban rail construction,an interaction model including rail,steel spring floating slab and tunnel floor is established with software ANSYS. Taken into consideration are such influence factors as the deformation mode of tunnel floor,the maximum deformation of the floor,the width of settlement trough,the deformation joints between floating slabs and so on. The deformation and the internal force of track,the detachment value and the detachment scope between floating slab and tunnel floor are calculated by means of numerical simulation. The results show that：（1） Uneven deformation of tunnel may induce the detachment between floating slab and tunnel floor due to their weak connection.（2） The rigidity of floating slab is the main cause for the difference of settlement between track and tunnel structure,and the rail fails to effectively constrain the deformation of floating slab.（3） With the increase of the settlement of tunnel floor,the deformation difference between track and tunnel structure increases,and the deformation difference decreases with the expansion of settlement trough.（4） The model mentioned above can comprehensively analyze the interaction between track and tunnel structure,which provides an effective method for calculating deformation and internal forces of existing track and the detachment between track and tunnel floor.