深埋隧洞管片衬砌结构受力分析

Numerical analysis of segment linings in deep buried tunnels

摘要

深埋水工隧洞在高内水压作用下，其管片结构受力变形情况十分复杂。依托深圳某隧道工程，从承担不同施工开挖荷载和不同管片拼装方式两个角度，探明高水压水工隧洞管片衬砌结构的力学特性。结果表明：(1)管片承担的施工开挖荷载越大，管片“横椭圆”变形越明显，管片环向应力分布越趋于“颈缩”形态。环向螺栓应力与管片接缝张开量有关，在承担不同施工开挖荷载时，管片接缝张开量分布情况有所不同。(2)错缝拼装结构环与环之间存在明显的位移错动，纵向螺栓和环间摩擦力的存在使其具有明显的纵向加强作用。(3)纵向螺栓可分担环向螺栓的受力状态，单环管片刚度明显小于多环管片，建议在数值模拟中剪力多环管片结构。(4)通缝结构管片基本不存在环间相互作用效应，错缝结构管片内力存在一个传递的过程，由中间环向两端下降，在管片间相互作用力及纵向螺栓的作用下，中间环管片刚度有所提升。

Abstract

Deep buried hydraulic tunnels bear both external soil and water loads as well as internal water pressure during operation. Under high internal water pressure, the stress and deformation of their pipe structure are very complex. Relying on the Changhua River Water Resources Allocation Project in Hainan Province, the mechanical characteristics of the segment structure of high-pressure shield tunnels were explored from two perspectives: bearing different construction excavation loads and different segment assembly method. The results show:(1) The larger the excavation load borne by the pipe segment, the more obvious the “transverse elliptical” deformation of the pipe segment, and the more the circumferential stress distribution of the pipe segment tends towards a “necking” shape. The stress of circumferential bolts is related to the opening amount of pipe joints, and the distribution of pipe joint opening amount varies when bearing different construction excavation loads.(2) There is significant displacement and displacement between the staggered assembly structure rings, and the presence of longitudinal bolts and friction between the rings gives it a significant longitudinal strengthening effect.(3) Longitudinal bolts can share the stress state of circumferential bolts, and the stiffness of single ring pipe segments is significantly lower than that of multi ring pipe segments. It is recommended to use shear multi ring pipe segment structures in numerical simulations.(4) There is basically no interaction effect between the rings in the seamless structure pipe segments, and there is a process of internal force transmission in the staggered structure pipe segments, which decreases from the middle ring to both ends. Under the interaction force between the pipe segments and the action of longitudinal bolts, the stiffness of the middle ring pipe segments is improved.

关键词

高水压 / 盾构隧洞 / 开挖荷载 / 管片拼装方式 / 受力变形

Key words

high water pressure / shield tunnel / excavation load / assembly method of pipe segments / deformation and stress

Author summay

张 芳(1987—), 男, 高级工程师, 硕士, 主要从事水利工程建设管理及相关技术研究。E-mail: [e-mail]；

叶文坤(1994—), 男, 工程师, 硕士, 主要从事水利工程建设管理及相关技术研究。E-mail: [e-mail]