构皮滩水电站坝址区软岩特性及处理技术

Soft rock characteristics and treatment technology in dam site of Goupitan Hydropower Station

构皮滩水电站坝址区软岩分布范围较广。软岩段围岩不稳定或极不稳定,自稳时间短,成洞条件差。根据软岩特性与计算分析,提出了"短进尺、弱爆破、及时支护"的开挖与支护原则,在运用各种试验与监测手段查明软岩的特性、分布及变形规律的基础上,施工中采取分层开挖、多期支护等合理的开挖程序与工艺,以及支护措施,成功克服了软岩成洞条件差、安全风险大等工程难题。

The soft rock is distributed widely in the dam site of Goupitan Hydropower Station. The surrounding rock in soft rock area is unstable or extremely unstable with short self - stable time and bad tunneling conditions. According to the characteristics of soft rock and calculation analysis, we advance the principles of ＂ short footage, weak blast and timely support＂. Reasonable excavation process and technology such as stratified excavation and multistage support are adopted in the construction, so as to overcome the engineering problems of bad tunneling conditions and great safety risk.