泄水式管片衬砌泄流量对衬砌外荷载的影响研究

Study of influence of water discharge volume on lining external loads for discharge segment lining

提出了采用泄水式管片衬砌结构型式解决铁路隧道高水压问题的结构设计理念。考虑渗流场对围岩应力场的影响,建立了水荷载为渗透体积力的管片衬砌外荷载计算公式,探讨了围岩渗透系数与最大可泄流量、衬砌控制泄流量与衬砌壁后接触应力的相互关系,以及围岩条件对衬砌壁后有效应力和接触应力的影响规律,并将该计算方法与远场水荷载视为面力的简易衬砌外荷载计算方法进行对比,以评估简易方法的可行性。结果表明:将水荷载视为面力与将其视为渗透体积力进行接触应力计算时,两者结果仅在一定条件下具有良好的接近度,前者只能作为衬砌外荷载选择的一种参考。

The design idea of solving high-water pressure effect on railway tunnels is brought forward by using water releasing segment lining. Considering the influence of seepage field on stress field of the ground field, the external loads calculation formula of segment lining by treating water load as permeation bulk forces are established; the interrelations between infiltration coefficient of surrounding rock and maximum discharge volume, the interrelations between controlled discharge volume and contact stress behind the lining are discussed; and the influence laws of surrounding rock conditions on effective stress and contact stress behind the segment are studied. Finally, the method is contrasted with a simple method which calculates segment lining external loads through treating far-field water loads as surface forces in order to evaluate the feasibility of the simple method. The results show that two calculation results by treating water load as surface forces and permeation bulk forces have a good approach only in given conditions, so the former method only can be a reference in selecting segment lining external loads.