基于结构受力模式主动调整的高速铁路单线隧道预制拼装衬砌设计选型研究

基于荷载-结构模型分析了不同等级围岩条件下350 km/h单线隧道断面整体衬砌内力特征.在此基础上,通过主动调整结构受力,在整体衬砌对应的弯矩极大值处将衬砌结构分为7部分进行预制,分析了不同围岩等级下接头刚度对预制装配式衬砌受力与变形的影响.结果表明:相对于整体衬砌,Ⅲ,Ⅳ,V级围岩条件下预制装配式衬砌最大轴力分别增加5.6%,6.5%,7.3%,最大弯矩分别减少39.9%,43.0%,54.6%,最大横向位移分别增加22.4%,36.4%,64.7%,最大竖向位移分别增加41.8%,44.6%,52.5%;边墙、拱脚和仰拱安全系数略有下降,拱顶和拱肩安全系数大幅增加,接头刚度不宜大于45 MN·m/rad.

Design and Selection of Prefabricated and Assembled Lining for Single Track Tunnel of High Speed Railway Based on Active Adjustment of Structural Stress Mode

Based on the load-structure model,the internal force characteristics of the whole lining of 350 km/h single track tunnel section under different levels of surrounding rock were analyzed.On this basis,the lining structure was divided into seven prefabricated parts at the maximum bending moment corresponding to the whole lining by adjusting the force on the structure actively,and the influence of the joint stiffness on the stress and deformation of prefabricated and assembled lining under different surrounding rock grades was analyzed.The results show that,compared with the whole lining,the maximum axial force of prefabricated and assembled lining increases by 5.6%,6.5%,7.3%,the maximum bending moment decreases by 39.9%,43.0%,54.6%,the maximum lateral displacement increases by 22.4%,36.4%,64.7%,the maximum vertical displacement increases by 41.8%,44.6%,52.5%respectively under the condition ofⅢ,ⅣandⅤgrade surrounding rock.The safety coefficient of side wall,arch foot and invert decreases slightly,the safety coefficient of arch crown and arch shoulder increases greatly,and the joint stiffness should not be greater than 45 MN·m/rad.