浅埋偏压隧道支护结构受力特性及施工优化方案研究

The Study on Force Characteristics and Construction Optimization Scheme of Supporting Structures for Shallow-buried and Unsymmetrical Loading Tunnel

以山西某浅埋偏压隧道为依托工程,全面总结分析其工程特性,利用数值模拟手段研究其初期支护结构的应力、应变特征,并提出相应的施工优化方案。研究结果表明:在浅埋偏压地形条件下,隧道支护结构受力极不均衡,左右边墙、地表部位发生较大的水平位移,拱顶、基底处产生较大的竖向位移;而最大轴力值和弯矩值均发生在隧道右侧拱脚处,不利于隧道的整体稳定性;通过采取增设临时支撑、地表注浆等工程措施,提高初期支护结构的整体稳定性。研究成果为类似工程设计施工提供了借鉴意义。

Relying on a shallow-buried and unsymmetrical loading tunnel in Shanxi, this paper comprehensively analyzed its engineering characteristics, studied the stress and strain features of preliminary supporting structure by means of numerical modeling and put forward corresponding construction optimization scheme. The research result revealed that the force of the tunnel supporting structure was imbalanced under shallow-buried and unsymmetrical topographic condition with great horizontal displacement taking place in left and right walls and surface as well as great vertical displacement taking place in vault and base. However, both the maximum axial force value and bending moment value occurred in the right arch foot of tunnel, which was adverse to the overall stability of tunnel. The overall stability of preliminary supporting structure could be improved by adding temporary support and surface grouting etc. engineering measures. The research findings have provided reference for design and construction of similar projects.