布仑口水电站高温引水发电隧洞受力特性研究

新疆布仑口-公格尔水电站位于西昆仑山腹地,在强烈的新老地质构造运动作用下引水发电隧洞前段存在高地温现象(实测温度105℃),严重影响隧洞施工和支护结构的耐久性。采用解析方法研究了该隧洞围岩和支护结构的温度分布规律和受力特性。首先采用瞬态和稳态两种方法研究温度分布规律,在此基础上研究了温度和应力耦合作用下围岩和支护结构的受力特性,最后初步设计了衬砌伸缩缝间距。研究表明低温冷水对围岩和支护结构的温度场影响显著,过水瞬时围岩内壁温度发生骤降(ΔT=60℃);运行期支护结构应力近似呈线性分布,而围岩应力却表现出明显的非线性特性。

Analysis of mechanical characteristics for high-temperature diversion tunnel of Bulunkou hydropower station

Xinjiang Bulunkou-Gongeer hydropower station is located in the heartland of West Kunlun Mountains. With the action of the old and new tectonic movement， there exists high temperature in the front section of the diversion tunnel (the measured temperature is about 105℃), which has great impacts upon construction progress and the durability of the supporting structure. An analytical method has been used to make studies of the temperature distribution and stress characteristics of the surrounding rocks and the supporting structure. Firstly， both the transient and steady methods are used in studying the temperature distribution. Furthermore， the stress characteristics of the surrounding rocks and the supporting structure are also investigated in consideration of the coupling effects of temperature and stresses. Lastly， the spacing of the contraction joints to the lining structure is designed in this paper. The research results show that the stresses of the supporting structure are characterized by near-linear distribution， but the stresses of the surrounding rocks have obvious non-linear characteristics during the diversion tunnel operation period. When the cold water flows through the diversion tunnel， the temperature in the inner wall plummets and the variation amplitude is about 60℃.