基于DDA理论对超前锚杆加固在破碎带工程围岩起销钉作用机理研究

Study on pilot bolt reinforcement with dowelling function in project surrounding rocks of broken zone base on DDA theory

尽管径向锚杆支护原理研究比较成熟,但对于超前(纵向)锚杆机理研究相对少,目前普遍认为超前锚杆对围岩起销钉、人为拱效应、组合梁等作用,但基本上是定性方面的研究,在数值理论研究较少。基于DDA(discontinuous deformation analysis)理论,对破碎带工程围岩中超前锚杆对破碎带岩块的销钉作用进行理论研究,得出预应力锚杆能对节理岩体起到销钉加固作用,而且预应力值越大,加固作用越明显。锚杆的几何参数如长度、倾角、倾向、刚度等参数对破碎带岩体锚固起到至关重要的作用。

Although the study on the radial bolt support principle was relatively matured, the study on the pilot （longitudinal） bolt mechanism was less conducted. At present, it was held generally that the pilot bolt would have the dowelling, artificial arch effect and combined beam function to the surrounding rocks and such study basically was a qualitative study with less study on numerical theory. Base on the DDA （ discontinuous deformation analysis ） theory, the paper had a theoretical study on the dowelling function of the pilot bolt to the broken zone of the project surrounding rocks. The pre - stressed boh could have the dowelling reinforcement function to the joint rocks. The higher of the pre - stressed value would have more obvious in reinforcement function. The geometric parameters of the bolt, such as the length, inclined angle, inclination, rigid and others would have the critical important functions to the rock bolting in the broken zone.