宁东铁路跨下伏输水隧洞的静动力计算及可行性分析

为了评价铁路修建的可行性及运营期间列车荷载对下伏输水隧道钢筋混凝土结构的安全性影响,开展了岩基-隧道钢筋混凝土结构的静动力计算研究,分析了移动列车荷载作用下岩基和衬砌的质点最大位移、最大主应力、振动位移和振动速度的变化规律。结果表明,列车移动荷载引起的岩基及衬砌结构的最大应力低于材料的容许应力;振动位移和振动速度时程曲线具有明显的三阶段特征,且同一列车速度时振动曲线特征点的对应时刻基本相当;振动位移的影响深度随列车速度的增加而增加,衰减完成的时间随列车速度的增加而减少。在输水隧洞上方修建铁路对其钢筋混凝土衬砌结构的安全性影响甚小,无需加固处理。

Static and Dynamic Calculation and Feasibility Analysis of Ningdong Railway Crossing above a Water-conveyance Tunnel

Static and dynamic FEM analysis is made on the rock base and concrete lining of a water conveyance tunnel in order to evaluate the feasibility to build a railway crossing above the water conveyance tunnel and to evaluate the effect of the moving train on the safety of the reinforced concrete structure of the underlying water conveyance tunnel. The variation rules of the maximum displacement, the maximum principal stress, the vibrating displacement and the vibrating velocity of the particles of the rock base and concrete lining under the load of the moving train are analyzed in detail. Conclusions drawn are as follows: The maximum stresses on the rock base and concrete lining induced by the moving load of the train is less than the allowable stress of the materials; The curve of vibration displacement VS vibration velocity has an obvious three stage feature, and the characteristic point of the vibration curves basically matches with the corresponding time under the same train speed; The influence depth of the vibration displacement increases as the train speed increases, while the decay time reduces as the train speed increases; The construction of the railway above the water conveyance tunnel has little effect on the safety of the reinforced concrete lining structure of the water conveyance tunnel and therefore no further consolidation is needed.