深立井井筒围岩破坏机理及井壁结构设计

Mechanism of Deep Shaft Surrounding Rock Failure and Shaft Wall Structure Design

为指导赵固二矿井筒建设,综合理论分析、数值模拟等方法,对井筒围岩损伤变形及井壁结构进行研究,结果表明:井筒穿越地层水平围压系数为1.75~1.86,导致软弱地层井筒塑性区蝶化分布,塑性区尺寸与双向主应力关系的RPP特性围岩强度影响较大;当埋深500~600m时,在冻结前后,及时浇筑井筒围岩损伤形态尺寸差异较大。基于此,确定选择冻结法施工,理论计算设计并校核了井壁结构参数,现场施工监测显示设计参数能够满足工程建设的安全稳定,为类似条件井筒建设提供参考。

To provide effective guidance for shaft construction,theoretical analysis and numerical simulation were used to study the damage and deformation of the surrounding rock and the structure of the shaft wall.The results show that the horizontal confining pressure coefficient for shaft crossing geological formations is 1.75 to 1.86,leading to a butterfly-shaped distribution of the plastic zone in the weak strata.The RPP characteristics of the relationship between plastic zone size and bidirectional principal stress have a significant impact on the strength of the surrounding rock.The size differences of the damage forms of the wellbore surrounding rock before and after freezing and timely pouring are significant at a burial depth of 500~600 meters.The freezing method was selected for construction before and after freezing based on the vector displacement of the surrounding rock.Based on this,the theoretical calculation and design of the shaft wall structure parameters were verified,and on-site construction monitoring shows that the design parameters can meet the safety and stability requirements of the project construction.The research results have practical significance for the construction of similar shafts under similar conditions.