特厚富水软岩巷道钢管混凝土支架支护技术研究

Study on support technology of concrete- filled steel tubular in roadway with huge thick and rich water soft rock

为解决查干淖尔一号井井底车场极软岩巷道支护问题,结合井底车场巷道围岩物理力学性质和原有支护条件下巷道破坏情况,运用修正的芬纳公式估算出围岩压力为0.9 MPa,计算理想状态下原有支护体可提供的支护反力为0.718 MPa,以支护体可提供的支护反力大于巷道稳定所需支护反力作为巷道稳定的必要条件,认为原有巷道发生变形破坏的主要原因是支护体支护反力不足,提出了钢管混凝土支架+厚混凝土喷层复合支护方案进行巷道返修,该方案理论上可提供1.48 MPa支护反力。结果表明:巷道返修完成2年后,两帮最大移近量为89 mm,顶底板最大移近量为142 mm。混凝土喷层没有开裂现象,巷道未发生明显变形,基于钢管混凝土支架支护技术的复合支护能有效控制巷道围岩变形。

In order to solve the support problem of extremely soft rock roadways in shaft bottom of Chagannaoer No. 1 Coal Mine,combined with the physical and mechanical properties of the surrounding rock and the damage situation of the roadway in the original support conditions,the paper used modified Fenner formula to estimate the value of the surrounding rock pressure of 0. 9 MPa,the reaction force provided by original support was 0. 718 MPa in the ideal state. The requirement of the roadway stability was that the support reaction force provided by support structure was bigger than the support reaction force needed by stabilizing the roadway. This paper suggested that insufficient reaction force was the main reason of the roadway surrounding rock deformation. A composite support scheme which was made up of concrete- filled steel tubular and thick concretes shotcrete layer was proposed to repair the roadway,this scheme could provide 1. 48 MPa supporting reaction force theoretically. The result showed that after the roadway repaired two years,the maximum rib to rib convergence of the roadway was 89 mm,maximum roof to floor convergence was 142 mm. There was no cracking phenomenon in shotcrete layer and no obvious deformation of roadway. The composite support scheme which based on concrete- filled steel tubular support could control the deformation of roadway effectively.