高地温引水隧洞围岩与喷层结构热力学参数敏感性分析

Sensitivity Analysis of Thermodynamics Parameters of Surrounding Rock and Supporting Structure in High Ground Temperature Diversion Tunnel

以新疆某水电站引水隧洞高地温段为研究对象,以现场监测获得的环向应力、温度数据为基础,对围岩和喷层结构的热力学参数(导热系数、比热、对流系数和线膨胀系数)与喷层环向应力的关系进行了分析,并采用参数敏感性分析法,研究围岩与喷层热力学参数对喷层应力的敏感性。结果表明,围岩和喷层的热力学参数对喷层拱顶环向应力的敏感度排序为:喷层线膨胀系数>喷层导热系数>围岩的导热系数>对流系数>围岩的线膨胀系数>围岩的比热>喷层的比热,拱顶环向应力对喷层线膨胀系数、喷层导热系数、围岩导热系数、对流系数比较敏感,而对围岩线膨胀系数、围岩比热和喷层比热不敏感。

Taking the section in high temperature field of the diversion tunnel of a hydropower station in Xinjiang as study object, the relationships between the mechanical parameters （thermal conductivity, specific heat, convection coefficient and linear expansion coefficient） of surrounding rock and shoterete layer structure and the circumferential stress of shotcrete layer are studied based on on-site stress and temperature monitoring data, and the sensitivity of thermodynamic parameters of surrounding rock and shotcrete layer to shotercte stress is also studied by using parameter sensitivity analysis method. The results show that the main influence factors on the circumferential stress of tunnel vault are ordered as linear expansion coefficient of shoterete layer, thermal conductivity of shoterete layer, thermal conductivity of surrounding reek, convection coefficient, linear expansion coefficient of surrounding rock, specific heat of surrounding rock and specific heat of shoterete layer, in which, the linear expansion coefficient of shotcrete layer, thermal conductivity of shotcrete layer, thermal conductivity of surrounding rock and convection coefficient are more sensitive and the linear expansion coefficient of surrounding rock, specific heat of surrounding rock and specific heat of shotcrete layer are not sensitive to the circumferential stress of tunnel vault.