底角锚杆在深部软岩巷道底臌控制中的机制及应用研究

MECHANICS AND APPLICATION RESEARCH ON THE FLOOR ANCHOR TO CONTROL THE FLOOR HEAVE OF DEEP SOFT ROCK ROADWAY

底臌作为深部巷道围岩变形与破坏的主要方式,一直是煤矿深井开采及其他地下巷道工程中难以解决的问题之一,如何有效地控制底臌成为巷道支护中首要考虑的问题。通过多个试验巷道工程底臌控制措施的对比研究表明,底角锚杆技术对于控制底臌起到了积极的作用。运用三维数值模拟方法,研究底角锚杆在控制巷道底板变形中的力学过程,分析分步开挖下底角锚杆力学性能发挥的时间效应,从而提出底角锚杆控制底臌的工作机制。底角锚杆在控制底板变形中的作用,主要是通过成排置入底板的杆体,利用材料自身的抗弯刚度,切断底板基角部位的塑性滑移线,对于岩体结构为块状结构或块裂结构的深部软岩巷道支护工程,可以有效控制巷道底臌。同时,结合具体的深部巷道工程实例,针对巷道底臌的变形机制及变形特征,合理应用底角锚杆控制底臌技术,提出非对称设计方法,有效控制了底板变形,对于深部巷道底臌的控制及防治具有理论指导意义。

As the main failure mode in deep adjoining rock roadway,floor heave is one of the most difficult problems to be solved in deep coal mines and other subsurface projects. How to control the floor heave effectively becomes a crucial matter that should be taken into account in supporting engineering. The contrastive studies to control the deformation of floor in lots of cases show that anchors fixed in floor can function positively. By using the method of 3D numerical simulation,the mechanical process of the anchors fixed in floor is studied,and the time effects of their mechanical properties are also analyzed. Based on the analysis results,the work mechanism of the anchors in floor is summarized. The anchors with high flexural rigidity are fixed into the floor in rows,and they can cut off the plastic slip line of the floor,so the deformation of the floor is controlled effectively. Particularly,the technique is suitable for the deep rock roadway of which rock mass structure belongs to blocky structure. Meanwhile,based on the previous studies,this technique is used in a deep roadway engineering,and the asymmetric design method is applied according to the deformation characteristics of floor,which controls the floor deformation successfully and can be as an instructive theory to floor heave control of deep roadway.