The main factors influencing the integrity and stability of the anchor bolt support
1 The strength of surrounding rock of roadway
Roadway surrounding rock hardness decided that whether the anchor bolt to play a supporting role, if the soft surrounding rock, which can appear the condition of deformation, so as to make the roadway maintenance difficult;If the surrounding rock hardness strong, natural surrounding rock load capacity is strong, the stability of the roadway is relatively high, the maintenance of roadway.
The hardness of surrounding rock are determines the load bearing capacity of surrounding rock,load ability strong degree is sufficient, so the maintenance effect is good.
2 ground stress
In-situ stress include gravity stress, tectonic stress, the mining stress concentration.Gravity stress refers to the geotechnical itself weight caused by stress, it
The strength of the force is decided by the weight of the rocks and buried depth.If the roadway and the distance from the earth's surface is larger, deformation of surrounding rock is easier, relative to the surrounding rock
Stability is lower, so the tunnel buried depth of influence for the stability of surrounding rock.Geological tectonic stress refers to the geological formation some tectonic system
If need to stress, tectonic stress, tectonic development faster, which is, the less the
development degree of surrounding rock, and then the stability of surrounding rock of roadway
is the worse.Mining refers to the mining of stress concentration of stress, when the distanceof roadway and coal mining area is very close, the mining stress is very big,
The mining stress is directly related to coal roadway, mining thickness.Roadway surrounding rock under the pressure of coal seam under the action of, also from
Mining stress, the influence of it is being squeezed from two kinds of force at the same time,which will affect the stability of roadway.
2.3 roadway cross section roadway cross section shape and size
The stress distribution of section will change along with the change of shape, so if you want to improve the stress distribution of surrounding rock, can change
The shape to achieve the effect, such as round, oval cross section, its stress distribution is uniform, trapezoidal and rectangular comparison will be worse.and, besides are influenced by the shape, also due to the width and height of the roadway, so take fully considering all the above factors.