浅埋富水地层防水型铁路隧道衬砌结构力学特性分析

Analysis on Mechanical Characteristics of Waterproof Railway Tunnel Lining Structure in Shallow-buried Water-rich Stratum

运用荷载-结构法,计算分析了不同地下水位线对浅埋富水地层铁路隧道衬砌结构轴力、弯矩峰值大小及位置的影响。计算分析结果表明:随着地下水位的降低,衬砌结构轴力峰值不断减小;衬砌结构弯矩峰值呈现出不同程度的波浪形增大;轴力在衬砌横断面上呈“鸡蛋”式分布。当地下水高于拱顶时,隧道衬砌结构轴力和弯矩值都比较大,设计时应将水荷载作为浅埋富水地层隧道结构受力的主要荷载之一。

The influence of different groundwater levels on the axial force,peak value and position of bending moment of railway tunnel lining structure in shallow-buried water-rich stratum is calculated and analyzed by using the load-structure method.The calculation and analysis results show that:the peak value of axial force of lining structure decreases continuously with the decrease of groundwater level;the peak value of bending moment of lining structure shows wavy increase in varying degrees;the axial force is"egg"distributed on the cross section of lining.When the groundwater is higher than the vault,the axial force and bending moment of the tunnel lining structure are relatively large.The water load should be regarded as one of the main loads of the tunnel structure stress in the shallow-buried water-rich stratum during the design.