CCS水电站地下洞室群围岩稳定关键技术研究

Study on Key Technologies of Rock Stability of Underground Powerhouse for CCS Hydropower Station

厄瓜多尔CCS水电站地下厂房系统为大跨度洞群,洞群空间上三向间距短,带来复杂三向薄岩壁问题;洞群区域节理发育且走向不利,易形成不稳定楔形体。立足于欧美规范,采用国内外工程类比法及二维、三维分析手段,基于“新奥法”最终提出了整体挂网喷混凝土加锚杆支护、局部型钢喷混凝土加锚杆支护的设计思路及在整体系统支护的基础上进行局部加固楔形体部位的设计理念,避免了大范围预应力锚杆及锚索对施工工期的延误。目前电站各安全监测数据无异常且已经长期收敛,证明了地下洞室群支护结构的合理性。

The underground powerhouse system of CCS hydropower station in Ecuador is characterized by large-span caverns and three direc-tions short distance in space, which brings about complicated three directions thin pillar problems. The joints development and strike unfavor-able in the caverns area, it is easy to form unstable wedge. Based on the European and American codes, using domestic and foreign engineer-ing analogy method, two-dimensional and three-dimensional analysis methods, and based on the “NATM”, the design ideas of integrally u-sing shotcrete with wire mesh and bolts, partially considering shotcrete with steel set and bolts for supporting, and the design concept of par-tial reinforcement for wedges on the basis of integral system support were finally put forward. This project had avoided the delayed construction period by large-scale pre-stressed anchors and cables. At present, the power station is running well, the safety monitoring data are not anoma-ly and have been converged for a long time, which certifies the rationality of the support structures for underground caverns.