复杂地质条件下隧洞支护结构稳定性分析

Research on the Stability of the Tunnel Supporting Structure under the Condition of Complicated Geology

为研究隧洞支护结构在复杂地质条件下的稳定性,以新疆塔什库尔干河齐热哈塔尔水电站引水隧洞为例,使用ANSYS Workbench软件建立了热-结构耦合分析模型,用数值模拟的方法分析了高地热、高地应力、地震等荷载作用的条件下,水工隧洞支护结构的稳定性。结果表明,在围岩与一期混凝土间设置隔热层能显著提高支护结构的稳定性,当二期混凝土衬砌厚度为0.25 m且过水断面形状为圆形时,只需适当提高二期混凝土的标号并按规范进行配筋,支护结构即能满足工程安全性的要求;在高地热、高地应力条件下,支护结构的地震位移响应与衬砌厚度基本符合线性关系,衬砌厚度每增加0.05 m结构的最大响应位移平均涨幅为7.72%。但当衬砌厚度较大时,支护结构可能与地震发生较大的响应,不利于结构的稳定性。上述计算结果与结论可为实际工程提供借鉴。

In order to study on the stability of the tunnel supporting structure under the condition of complicated geology,using ANSYS Workbench established thermal- stress analytical model,we analyzed the stability of the tunnel supporting structure under the condition of high geothermal,high crustal stress and earthquake. The results show that the heat insulation layer between the rock and lining can obviously improve the stability of the tunnel supporting structure. The supporting structure can meet the requirements of engineering safety when concrete lining thickness' s 0. 25 m and its shape of cross section is circle. The seismic displacement response of the supporting structure and lining thickness basically conform to the linear relationship,the lining thickness increased 0. 05 m while the maximum response displacement of structure increase about 7. 72%. But,when the thickness of the lining is larger,supporting structure may be related to the earthquake response of the larger,it's not conducive to the stability of the structure. The calculation results and the conclusion above can provide reference for practical engineering.