松软破碎井筒综合加固技术研究与实践

Study and Practice on Combined Technology for Reinforcing Soft and Fractured Shaft

潞安屯留矿副井井筒由于所处岩层地质条件差,同时受到附近硐室、大巷施工及围岩变形、破坏的影响,导致井筒破坏严重.采用现场测试、理论分析、数值模拟与井下试验相结合的研究方法,开展了松软破碎井筒变形破坏机理与加固技术研究.研究结果表明:井筒+400 m水平附近厚层软岩基本处于破碎状态,裂隙非常发育,属于典型的松软破碎节理化软岩;井底车场及硐室群开挖后,在副井井筒附近、马头门顶板以上50 m范围内产生了应力集中现象,是副井变形严重的主要原因;井筒下部马头门及硐室围岩变形与破坏,导致井筒出现较大范围的剪切破坏区;注浆与强力锚杆、锚索联合加固是比较适合松软破碎井筒的加固方式.综合加固技术在现场得到成功应用,保证了井筒的长期稳定.

The auxiliary shaft of Tunliu coal mine in Lu＇an coal mining area is severely destroyed because of being poor in geological strata condition,and affected by the excavation of nearby chambers,main roadways and the deformation of surrounding rock mass.The deformation and damage mechanism of the soft and fractured shaft and its reinforcing technology were studied with the combined method of field testing,theoretical analysis,numerical simulation and underground experiment.The research results show that 1） the thick soft rock mass around the shaft close to level ＋400 m is basically broken with developed fissures,belonging to the typical soft and fractured jointed rock type;2） the stress concentration occurs in an range 50 m above the roof of horsehead around the shaft when the underground station and chambers are excavated,which is the main reason for the severe shaft deformation;3） the large shear damaged zone around the lower part of the shaft is caused by the deformation and damage of the rock mass surrounding the horsehead and chambers;4） the combination of grouting with intensive bolts and cables is an effective reinforcement form suitable to the soft and fractured shaft.The combined reinforcement technology has been successfully applied in the field,well ensuring the long term stability of the shaft.