石林隧道支护结构破坏特征及其机理分析

发布时间：2018-05-04 07:57

本文选题：隧道 + 支护结构　；参考：《公路工程》2017年02期

【摘要】：石林隧道位于永宁高速公路的永安段,地质条件复杂,构造应力偏高,富水,断层褶皱发育,岩体软弱破碎,隧道基底强度低,围岩自稳能力极差。当隧道开挖后,围岩产生强烈变形、主要表现为拱顶沉降大,累计沉降达1.2 m;支护结构被严重破坏,喷射混凝土层出现开裂和剥落,工字钢拱架被压变形;同时,仰拱出现上拱现象,并伴随较大面积的裂缝出现;同一隧道段,二次衬砌还发生了严重的纵向和横向开裂。从围岩强度条件、地下水作用、构造应力条件以及隧道变形破坏特征等方面,分析了隧道支护结构变形破坏的根本原因和机制,并进行了相关的理论计算,认为它是隧道开挖卸荷后,围岩强度低、纵向承载力差异、塑性流动与膨胀等共同作用的结果。基于对隧道围岩变形破坏机理分析后,针对病害采取了一系列的治理措施,确保隧道顺利贯通,同时也可为类似工程的处置提供参考借鉴。
[Abstract]:Shilin Tunnel is located in Yongan section of Yongning Expressway. The geological conditions are complicated, the tectonic stress is high, the water is rich, the fault fold is developed, the rock mass is weak and broken, the base strength of the tunnel is low, and the self-stability ability of surrounding rock is extremely poor. When the tunnel is excavated, the surrounding rock produces strong deformation, which mainly shows that the dome settlement is large, the accumulative settlement is up to 1.2 m, the support structure is seriously damaged, the shotcrete layer is cracked and spalling, the I-steel arch frame is compressed and deformed, at the same time, In the same tunnel section, the secondary lining also has serious longitudinal and transverse cracking. From the aspects of surrounding rock strength condition, groundwater action, tectonic stress condition and tunnel deformation and failure characteristics, the fundamental causes and mechanism of tunnel supporting structure deformation and failure are analyzed, and relevant theoretical calculations are carried out. It is considered that it is the result of low strength of surrounding rock, difference of longitudinal bearing capacity, plastic flow and expansion after excavation and unloading of tunnel. Based on the analysis of deformation and failure mechanism of tunnel surrounding rock, a series of treatment measures are taken to ensure the smooth passage of tunnel, which can also be used for reference for similar projects.
【作者单位】：中国地质大学(武汉);三明市交通建设投资有限公司;
【基金】：北京化工大学青年科学基金(QN0622)
【分类号】：U455.7

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