小孟底沟水电站引水隧洞岩爆预测和防治对策

Forecast and countermeasures of rockburst in diversion tunnel of Xiaomengdigou hydropower station

以小孟底沟水电站工程引水隧洞为例,依据隧洞区地应力的测试值及地应力场模拟与反演,综合分析了隧洞区地应力和隧洞围岩应力的分布规律,在此基础上计算获得开挖后洞周围岩应力值。在分析岩爆发生条件的基础上,根据工程区地应力、岩性等特征,采用多种岩爆判别方法,对引水隧洞围岩发生岩爆的可能性及岩爆级别进行了综合预测,给出勘察设计阶段隧洞产生岩爆的可能性及级别,从而为设计和施工提出应对岩爆的工程对策。

With the case of diversion tunnel of Xiaomengdigou Hydropower Station, the distribution law of geostress in the tunnel area and surrounding rock stress is analyzed comprehensively based on simulation and inversion of geostress field. Based on this, the stress value around the tunnel after excavation is calculated. Moreover, on the basis of analyzing the condition of rock- burst, the possibility and the level of rockburst in diversion tunnel are forecasted synthetically using the various rockburst identification methods according to the characteristics of geostress and lithology. Countermeasures of dealing with the rockburst are finally proposed.