超大断面隧道变截面衬砌台车应力特征

Stress Characteristics of Variable- section Lining Trolley of Super-large Section Tunnel

摘要:

以京张高铁八达岭长城站为工程依托，对超大断面隧道变截面衬砌台车的动态、静态应力进行研究，分析了截面变化对台车不同结构应力的影响规律。通过数值模拟分析台车结构的静态应力特征，利用现场监测分析台车结构的动态应力特征以及变截面对台车结构应力变化的影响规律。结果表明：台车结构静态应力和位移存在不均匀分布现象，各结构呈多变特征，部分结构出现明显的应力集中；浇筑过程中，应力呈现外侧大内部小的规律；台车浇筑区域位于支撑结构上方时应力最大，混凝土凝固过程中台车结构应力基本不变；台车截面由小至大变化时，各结构应力增大，其中拱肩丝杆是应力变化最大的构件。

Abstract:

Based on the Badaling Great Wall Station of Beijing-Zhangjiakou High-speed Railway， the dynamic and static stresses of variable-section lining trolley of super-large section tunnel were studied， and the effect of cross-sectional changes on the trolley structure was analyzed. Numerical simulation was used to analyze the static stress characteristics of the trolley structure， and the field monitoring was used to analyze the dynamic stress characteristics of the trolley structure and the influence law of cross-sectional changes on the stress of the trolley structure. The results show that： the static stress and the displacement of the trolley structure are unevenly distributed， and each structure is variable， with some structures showing obvious stress concentration. During the pouring process， the stress is larger on the outside and smaller on the inside； the stress value is the largest when the trolley pouring area is located above the supporting structure， and the stress of the trolley structure is basically constant during the concrete solidification process. As the cross section of the trolley becomes larger， the stress of each trolley structure increases. The arch shoulder screw is the member with the greatest change in stress.