CCS水电站地下厂房枢纽关键点设计研究与实践

Study and Practice of Critical Points of Underground Powerhouse Design for Coca Codo Sinclair Hydropower Project

厄瓜多尔CCS水电站地下厂房洞室群规模宏大,布置密集,洞间围岩存在薄岩壁失稳问题。合同约定的机组安装高程低,存在高水位发电时下游河道水位壅高导致机坑水位升高的问题,另外尾水边坡为火山灰高边坡,坡面有多条冲沟,地质条件复杂,存在边坡失稳问题。设计采用工程类比法、二维及三维分析手段、反演分析法确定边坡地质参数,并采取施工及安全监测实时联动优化等措施,有效解决了一系列关键技术难题,为工程的安全运行奠定了坚实的基础。

Coca Codo Sinclair (CCS) Hydropower Project in Ecuador has a group of underground powerhouses featuring grand caverns ar-ranged in a concentrated way. Thin faces of surrounding rock among caverns are subject to instability. The contractual installation elevation of units is low, which would result in a problem of the water in downstream river channel banking up the water level in unit pit during power generation under high water level. The tailwater slope is high volcanic ash slope with multiple gullies developed and complicated geological conditions, which compromises the slope stability. During the design, engineering analogy, 2D & 3D analysis and inverse analysis were ap-plied to determine the slope geological parameters, and measures such as real time interaction of design, construction and instrumentation were taken. Such design had solved a series of key technical problems and established a firm foundation for safe operation of the project.