铁道标准设计2024，Vol.68Issue(6)：145-152,8.DOI:10.13238/j.issn.1004-2954.202210040002
水平层状碳质页岩地层高速铁路大断面隧道基底变形机理研究
The Deformation Mechanism of Large Section Tunnel Footings in Horizontally Laminated Carbonaceous Shale Strata for High-speed Railways
摘要
Abstract
In the western and southwestern regions of China,under-construction and completed high-speed railway tunnels often suffer from elevated floor heave,which seriously threatens the construction progress and operational safety of the tunnels.This paper relies on the typical horizontally laminated carbonaceous shale stratum of the Xingshandong Tunnel to carry out a research on the mechanism of elevation of the base of the back arch.The model of the surrounding rock below the base of the elevated arch is simplified by applying the method of qualitative analysis by component testing and quantitative calculation by numerical simulation.The effects of different layer thicknesses,interlayer cohesion and material strength on the damage pattern of laminated rock masses are revealed,the causes of bottom bulging in horizontally laminated rock enclosures are analysed and corresponding bottom bulge control and disposal techniques are proposed.The results indicate:(1)The reduction in layer thickness reduces the ability of the laminated composite rock mass to resist deformation and damage,mainly manifested in the shortening of the elastic phase and the acceleration of the deformation rate;the reduction in the bond strength between layers destroys the integrity of the laminated composite rock mass,leading to the acceleration of the laminated rock mass into the single rock layer stress phase,but the effect on the deterioration of ultimate bearing capacity is not obvious;the reduction in the strength of the rock mass itself greatly reduces the load-bearing capacity of the laminated composite rock formation,causing the damage process to accelerate significantly and further deepening the extent and scope of the impact,which,combined with the numerical simulation results,further proves that the strength of the rock mass itself dominates the deformation and damage of the laminated rock mass.(3)The fatigue damage of train vibration,the weakening effect of groundwater aggregation and the long-term mechanical properties of the surrounding rock will all affect the stability of the elevation arch of the tunnel,and the order of deformation control effect is:deepening invert＞base grouting＞invert arch bolt.关键词
高速铁路/铁路隧道/水平层状围岩/仰拱底鼓/构件试验/数值模拟/变形机理Key words
high-speed railway/railway tunnels/horizontally laminated surround rock/floor heave/component test/numerical simulation/deformation mechanism分类
交通工程引用本文复制引用
周俊超..水平层状碳质页岩地层高速铁路大断面隧道基底变形机理研究[J].铁道标准设计,2024,68(6):145-152,8.基金项目
国家自然科学基金高铁联合基金项目(U2034205) （U2034205）
