| ANSYS finite element numerical simulation software is adoped in this paper to analysis ground stress field and bolting plan under different ground stress conditions. The triaxiality finite element model of roadway was authorized about the parameter change of the rock bolt length and rock bolt spacing. The relations between ground stress state and the stability of roadway was studied on the basis of numerical simulation. And at the same time the influence of the structure and parameter of rock bolting to the stability of roof in the road along next goaf, when the length and spacing of rock bolt changed in different embedding depth and different underground stress. The influence about different initial prestressing force of rock bolt to the ability of roof of road was researched. Accordingly some research outcome is drawn as follows:1.At the same conditions of underground stress and embedding depth, the change of rock bolt length could not influence the change of stress and displacement in roof and floor at road. The central section and right angle part are the dangerous location of road. With the length of rock bolt increase, the pre-tensioning rock bolt must be high enough, or the rock bolt could not control the slice of road and the slice point could not be close yet. At the second stress state, when the length of rock bolt is 1.5m and the pre-tensioning rock bolt is 8t, the stability of roof of road is very well.2.At the same as length of rock bolt, underground stress and embedding depth, when the rock bolt spacing different the influence is very high at the control of slice of roof of road. But the change of rock bolt spacing could not change the mechanical property of surrounding rock or the road along next goaf. The density of rock bolt spacing is high; the low initial pre-tensioning rock bolt could control the slice of roof of road and increase the ability of the road along next goaf. Contrary, the high pre-tensioning rock bolt should be used in order to control effectively the slice of roof of road. We can conclude through simulate calculate, when the length of rock bolt is 2.1m, the conceal depth is 500m, the rock bolt spacing is 0.6m, the pre-tensioning of rock bolt is 8t, the slice of roof of road can be control. When the rock bolt spacing is 0.9m, the pre-tensioning of rock bolt reach to 20t, the slice of roof of road would be closed. |
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