公路隧道二次衬砌裂损病害机理研究

公路隧道二次衬砌裂损病害对隧道结构的稳定性有着很大影响,为研究公路隧道二次衬砌裂损病害发生的机理,首先划分了衬砌裂损病害的3种类型,并对每种裂损类型展开了力学行为分析.以断裂力学作为切入点,研究了在围岩荷载及结构自身作用下衬砌产生的裂缝的发展规律,通过获取应力强度因子K、J积分、以及裂纹面的最大张开位移δ求得裂纹尖端应力和应变值,在此基础上,通过最大周向应力理论分析了Ⅰ型＋Ⅱ型复合裂纹发生的临界条件.根据最大周向应力σθ所对应的应力强度因子值来对比临界强度因子值KIC,判断二次衬砌裂纹是否会发生扩展以及分析衬砌裂损病害发生的可能.获得了一系列有益的结论,能够对公路隧道二次衬砌裂损病害机理的理论研究和工程应用提供一定的参考和借鉴.

Study on Mechanism of Crack Damage Disease of Secondary Lining in Highway Tunnel

The crack damage disease of secondary lining in highway tunnel is of great influence on the stability of the tunnel structure. To study the mechanism of the secondary lining crack damage diseases in highway tunnel, firstly, this paper has division of the three types of lining crack damage disease and every crack damage types was analyzed on mechanical behavior. Then, with fracture mechanics as the breakthrough point, the lining crack law of development under the action of surrounding rock load and structure itself was studied. By getting the stress intensity factor, J integration and the maximum opening displacement of crack surface, the crack tip stress and strain values were obtained. On this basis, the critical conditions of type I and type U composite crack were analyzed through the theory of the maximum circumferential stress. Most important, according to the maximum circumferential stress of the stress intensity factor values, comparing the critical intensity factor value with that stress intensity factor value and eventually judge whether the secondary lining crack extension will happen and analysis of the possibility of lining crack damage disease occurs. The conclusions obtained in this article that can provide some reference for theoretical research and engineering application and reference to the mechanism of crack damage disease of secondary lining in highway.