软岩条件下大断面交岔点施工工艺及支护对策研究

Construction technology of large section intersection and supporting measures in soft rock

针对传统大断面交岔点施工支护设计方法和施工过程中的不足,通过对工程地质条件和软岩巷道变形破坏的机理进行综合分析,提出了"锚网喷+锚索+反底拱"支护设计方案。实践表明:大断面交岔点施工顺序为先施工小断面导硐,再扩掘至设计大断面;并采用光面爆破、及时支护、施工反底拱地坪形成封闭应力承载拱圈等施工工艺最大限度地发挥了围岩的自承能力,有效控制大断面硐室变形,为矿井的安全高效生产创造了条件。

Aiming at the deficiency of traditional support design method and construction process, the paper comprehensively analyzes the engineering geological conditions and the deformation and failure mechanism of soft rock roadway, puts forward the support scheme of bot-mesh-shotcreting＋cable＋inverted arch. The practice showed that the construction of large cross section intersection should start from small section pilot tunnel, which was then enlarged to large section ; the construction technology of smooth blasting, timely support and construction of inverted arch terrace to form the closed stress bearing arch ring and other construction technology to maximize the self-supporting capacity of the surrounding rock, which effectively controlled the deformation of large section chamber, and created conditions for the safe and efficient production of the mine.