地铁振动荷载作用下土体动剪应力分析

发布时间：2018-09-11 08:20

【摘要】：以南京地铁10号线下穿长江段大直径单洞双线盾构工程为背景,研究地铁列车振动荷载作用下大直径单洞双线地铁盾构隧道周围土体的动剪应力规律。采用车辆-轨道垂向统一模型,计算地铁运行时产生的轮轨力,借助有限元方法,将该轮轨力作为地铁列车荷载输入,系统分析单、双列车动载两种情况下,隧道周围土体的动剪应力,同时对冲切槽段冲刷前后土体动剪应力的变化进行对比研究。研究表明:地铁列车荷载作用下,隧道拱腰及底部区域动剪应力较大,动剪应力随列车通过数量增加而变化的幅度平缓;单列车通过时隧道周围土体动剪应力呈不对称分布;冲切槽段冲刷后隧道拱腰附近土体动剪应力增大,最大增加幅度达80%,其余区域较冲刷前减小,最大减小幅度约17%。
[Abstract]:Based on the large-diameter single-hole double-line shield engineering under Nanjing Metro Line 10, the dynamic shear stress law of the soil around the large-diameter single-hole double-line subway shield tunnel under the action of train vibration load is studied. The wheel-rail force generated by subway is calculated by using the vehicle-track vertical unified model. With the help of finite element method, the wheel-rail force is input as the load of subway train, and the dynamic load of single and double trains is analyzed systematically. The dynamic shear stress of the soil around the tunnel and the dynamic shear stress of the soil around the tunnel before and after scouring are compared. The results show that the dynamic shear stress in the arch and bottom of the tunnel is larger under the load of the subway train, and the amplitude of the dynamic shear stress varies slightly with the increase of the number of trains passing through the tunnel, and the dynamic shear stress of the soil around the tunnel is asymmetrical when the train passes by the single train. The shear stress of the soil near the tunnel arch waist increases after scouring in the section of the punching groove, the maximum increase amplitude is up to 80%, and the other areas are smaller than those before scouring, and the maximum decrease range is about 17%.
【作者单位】：同济大学道路与交通工程教育部重点实验室;
【分类号】：U451.3;U211.3

【共引文献】