溪洛渡水电站超大型地下厂房洞室群岩体工程控制与监测

CONTROL AND MONITORING OF ROCK MASS ENGINEERING OF SUPER LARGE UNDERGROUND POWERHOUSE CAVERN GROUPS AT XILUODU HYDROPOWER STATION

金沙江溪洛渡水电站地下厂房洞室群规模巨大,结构复杂,玄武岩组内层间与层内错动带致使岩体非连续性是主要地质问题。采用损伤弹塑性数值方法对围岩稳定性进行分析,确定洞室开挖顺序和支护参数。精细化施工组织,严格控制开挖对岩体的损伤范围,并保证洞室轮廓的良好成型。及时对监测数据进行分析和反演分析,对支护工作量进行动态设计。开挖过程中,位移和应力变化规律较好;开挖完成后,位移和应力总量值较小,洞室围岩稳定性良好。溪洛渡地下厂房洞室群规模为我国已建和在建工程之首,总结其设计、开挖与支护,监测与反演等岩体工程控制措施,对类似工程具有指导和借鉴作用。

The underground powerhouse cavern groups at Xiluodu hydropower station in Jinsha river has huge scale and complex structure.The discontinuity of rock mass induced by the disturbed belts between bedding and inner bedding is the main geologic problem.The elastoplastic damage theory is used to analyze the stability of surrounding rock;and the excavation sequence and supporting parameters for underground caverns are determined.Based on meticulous construction organization,the extent of damage to surrounding rock is strictly controlled to ensure good forming of caverns outline.Real-time analysis and inversion analysis of monitoring data are conducted;and the dynamic design for supporting workload is needed.In the process of excavation,the displacement and stress have a good change regularity.After excavation,the measured values of displacement and stress is relatively small;and the surrounding rock of underground powerhouse caverns has a good stability.The scale of underground powerhouse caverns at Xiluodu hydropower station tops the list in China.The summary from control measures for rock mass engineering such as design,excavation and support,monitoring data analysis and inversion analysis,can provide some references for the similar projects.