火成岩复杂地质环境巷道交岔点成套施工技术

Research on Integrated Construction Technology for Tunnel Conjunction in Complex Geological Circumstance of Igneous Rock

马钢集团姑山矿为典型的火成岩复杂地质环境,传统支护不能满足巷道的稳定要求;为采取合理的开拓与支护方案,对后和睦山矿段-300 m水平车场马头门南迎头N14交岔点进行了针对性研究,决定采用导硐施工方法,根据现场地质特点及锚网喷、锚注、锚索支护机理,采用锚网喷进行一次柔性支护,锚注与锚索联合进行二次加强支护的复合支护方案,取得了良好的技术效果与经济效益。研究结果表明,对于扰动较大的交岔点施工应及时进行柔性让压支护;对于破碎、易膨胀性围岩应及时进行封闭处理;对于大断面巷道或大松动圈围岩应进行锚注与锚索联合加强支护。

Gushan Iron Mine of MaSteel Group is in typical complex geological circumstances of igneous rock and the traditional support cant meet with the requirement on tunnel stability. In order to adopt a reasonable excavation and support scheme, research was made for the N14 tunnel conjunction which is near to the south working face at the shaft bottom of - 300 m level of Hou Hemuhan mine section. It is decided to adopt the pilot tunnel method for the excavation. According to the site geological characteristic and the support mechanism of bohing-shotcreting, bolting-grouting and pre-stressed anchor cable, it is decided to adopt a combined support scheme consisting of bohing-shotcreting for the primary flexible support and bolting-grouting and pre-stressed anchor cable for the secondary strengthening support, which has achieved good technical effect and economical benefit. The results show that the flexible stress-release support should be timely executed for the construction at the conjunction with great disturbance, the fractured and dilatable surrounding rock be rapidly sealed, and the support method combining bolting-grouting and pre-stressed anchor cable be used for large cross-sectional tunnel or the surrounding rock in large loose zone.