When the rock mass is not excavated, the stress in the rock mass is in the original equilibrium state, and the rock generally does not deform and move. However, after the roadway is excavated, the original stress balance in the rock body is destroyed, and the rock stress around the roadway changes. When the disturbed stress reaches a new equilibrium process, the rock around the roadway will be deformed, destroyed, and even drop. In order to ensure the safety of work and the normal production, in addition to the surrounding rock is quite stable and does not require special treatment, in the unstable section of the surrounding rock, certain measures must be taken to support the roadway.
Supporting materials including wood, metal materials, stone, concrete, reinforced concrete, mortar. Cement is a widely used cementitious material. In the past, most of the roadway support was erected with shed-type brackets and masonry stone (or concrete) integral brackets. Now, spray anchor support has been widely used in mines.
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