开滦膨胀软岩巷道变形机理及控制对策

Deformation mechanism and control of expansive soft rock roadway in Kailuan mining area

针对开滦矿区深部高应力下膨胀性泥质软岩巷道变形失稳的工程问题,应用X衍射、扫描电镜、单轴和常规三轴抗压试验等方法,测试分析了典型区域巷道膨胀性软岩的矿物成分、微观结构和物理力学特性,发现微观裂隙发育是围岩易吸水膨胀的主要原因,不同围压下主导围岩失稳的方式有拉破坏和剪破坏两种,采用传统锚固和架棚的支护方式不能有效发挥支护的承载效能,提出的多层次锚固注浆和底角卸压方案可将让压、支护和围岩改性协同起来,在高应力水解膨胀软岩中取得了较好的支护效果,为同类巷道的安全支护提供了范例和借鉴。

Aiming at the deformation and instability of expansive clayey soft rock roadway under deep high stress in Kailuan mining area,the mineral composition,microstructure and physical-mechanical properties of expansive soft rock in typical area are tested and analyzed by means of XRD,SEM,uniaxial and conventional triaxial compression tests.It is found that the development of microcracks is the main cause of water absorption and expansion of surrounding rock.There are two types of surrounding rock instability under different confining pressures:tension failure and shear failure.The traditional anchoring and scaffolding supporting methods can’t give full play to the bearing efficiency of support.The multi-level anchoring grouting and bottom angle pressure relief scheme in this paper can combine the pressure reduction,support and surrounding rock modification,and obtain good support effect in the soft rock with high stress hydrolysis and expansion,which provides an example and reference for the safe support in the same kind of roadways.