软硬不均浅覆土地层隧道衬砌结构受力研究

Study on the Stress of Tunnel Lining Structure in Uneven Soft and Hard Shallow Soil Layers

摘要: 软硬不均、浅覆土地层的盾构隧道建设面临复杂地质条件和高水压环境的挑战，其衬砌结构的受力特性直接关系到隧道施工与运营的安全性和稳定性。本文以某核电站排水隧道建设为背景，基于现场实测数据与数值模拟方法，系统研究了复杂地层条件下衬砌结构的力学行为及演化规律。研究分析了隧道施工过程中地层扰动对衬砌结构内力分布和变形特性的影响，探讨了地下水渗流作用及施工参数(如注浆压力、盾构推进速度)对衬砌结构力学性能的作用机制。结果表明：1) 地层扰动和渗流效应显著影响衬砌结构的内力分布与变形特性，尤其在软弱土层和浅覆土条件下，衬砌结构承受的附加荷载显著增大；2) 适当控制施工参数可有效降低衬砌结构内力峰值和变形幅度；3) 数值模拟揭示了衬砌结构在施工过程中的应力演化规律，为优化设计提供了重要依据。本文研究成果不仅为类似复杂地层条件下的隧道工程设计与施工提供技术参考，还为盾构隧道衬砌结构的优化设计及长期服役性能评价奠定了理论基础。

Abstract: The construction of shield tunnels with uneven hardness and shallow soil layers faces challenges from complex geological conditions and high water pressure environments. The stress characteristics of the lining structure directly affect the safety and stability of tunnel construction and operation. This article takes the construction of a drainage tunnel in a nuclear power plant as the background, and based on on-site measured data and numerical simulation methods, systematically studies the mechanical behavior and evolution laws of lining structures under complex geological conditions. The study analyzed the influence of geological disturbance on the internal force distribution and deformation characteristics of lining structures during tunnel construction, and explored the mechanism of groundwater seepage and construction parameters (such as grouting pressure and shield tunneling speed) on the mechanical properties of lining structures. The results indicate that: 1) geological disturbance and seepage effects significantly affect the internal force distribution and deformation characteristics of the lining structure, especially under weak soil layers and shallow overburden conditions, where the additional load borne by the lining structure increases significantly; 2) Properly controlling construction parameters can effectively reduce the peak internal force and deformation amplitude of the lining structure; 3) Numerical simulation reveals the stress evolution law of lining structure during construction, providing an important basis for optimizing design. The research results of this article not only provide technical references for the design and construction of tunnel engineering under similar complex geological conditions, but also lay a theoretical foundation for the optimization design and long-term service performance evaluation of shield tunnel lining structures.