溪洛渡水电站超大型地下厂房围岩监测资料分析和稳定性评价

Monitoring Data Analysis and Stability Evaluation for Surrounding Rock of Super-large Underground Powerhouse in Xiluodu Hydropower Station

水电站大型地下厂房具有规模大、结构复杂、交叉开挖率高等特点,开挖期围岩稳定控制难度大。为保证洞室群施工期围岩稳定,需建立有效的监测资料分析方法,对洞室围岩稳定进行评判。从监测分析内容、方法、分析思路出发,通过对位移和应力量级、分布特征、变化规律、影响因素进行分析,对地下厂房洞室群施工期围岩的稳定性进行评价。开挖完成后,围岩最大位移为60.14 mm,锚杆最大应力为242 MPa,围岩稳定性较好;围岩松动圈基本在3 m以内,支护参数合理有效。溪洛渡地下厂房洞室群规模为我国已建和在建工程之首,总结其监测资料分析和围岩稳定评价,对类似工程具有指导和借鉴作用。

The large underground powerhouse of hydropower station has the characteristics such as huge scale ,complex structure ,high rate of crossover excavation etc .,and it is difficult to control the stability of the surrounding rock in the excavation .In order to ensure the stability of the surrounding rock during the construction of underground caverns ,it is necessary to establish the effective analysis method of monitoring data ,so as to evaluate the stability of the surrounding rock .Here ,from the monitoring analysis content and method and thinking ,the magnitude ,distribution characteristics , change regulation and influence factor of surrounding rock displacement and supporting stress are analyzed to monitor the deformation of surrounding rock and evaluate the tunnel stability .The results show that after the completion of excava-tion ,the maximum displacement of surrounding rock is 60 .14 mm ,and the maximum stress of bolt is 242 MPa ,having a good stability of surrounding rock .The surrounding rock’s loose circle is smaller than 3 m ,and the support parameters are reasonable and effective .The scale of Xiluodu Hydropower Station’s undergronnd powerhouse caverns is the first in China ,the summany from the monotoring data analysis and stability evaluation of surrounding rock could provide some references for similar projects .