大岗山水电站地下厂房岩锚梁施工技术

Construction technology for rock anchor beam of underground powerhouse of Dagangshan Hydropower Station

大岗山水电站地下厂房跨度大、地质条件复杂,其中岩锚梁施工是地下施工技术的重点和难点。为了保证岩锚梁的顺利施工,在分析地质条件的基础上,确定了保证质量的关键施工节点,拟定了相应的施工措施。岩锚梁混凝土浇筑前先进行周边支护,并对排架基础进行处理,防止岩锚梁拉裂现象的出现;选择低温季节浇筑混凝土,并通水冷却,有效地防止了温度裂缝;混凝土养护时,采取覆盖塑料薄膜和棉被的措施,使混凝土表面浇筑质量达到饰面混凝土的标准。

The underground powerhouse of Dagangshan Hydropower Station is characterized by large span,complicated geological condition and the construction of rock anchor beam is the key and difficult point of underground construction.In order to guarantee the smooth construction of rock anchor beam,on the basis of analysis of geological condition,the key construction links and corresponding measures for guaranteeing construction quality were determined.The measures are as follows：① before Before concrete grouting for rock anchor beam,the surrounding support were conducted and the foundation of bent frame structure was treated,to prevent cracking.;② the The concrete grouting was performed under low temperature and cooled by water,to effectively avoid temperature crack;③ In concrete curing,plastic membrane and quilt was used to cover the concrete,to satisfy the quality demand of facing concrete.