Method for reinforcing overlying shallow rockmass in mined-out area

Abstract

The invention belongs to the technical field of civil engineering reinforcement, and particularly relates to a method for reinforcing an overlying shallow rockmass in a mined-out area and a special tool used in the method. The method for reinforcing the overlying shallow rockmass in the mined-out area mainly comprises the following steps: (1.1) forming holes: drilling the ground surface above the mined-out area at intervals of 2-3m when construction is performed, wherein the drilled holes are vertically downward; (1.2) inserting two or more than two deformed steel bars welded in parallel into each drilled hole, and exposing out of the ground surface by 10-15cm; (1.3) inserting a grouting pipe into each drilled hole to perform pressure grouting to form an anchor rod pile; and (1.4) casting a concrete slab on the ground surface, arranging single layer or multiple layers of reinforcing bars, and welding the parts of the anchor rod piles, which are exposed out of the ground surface, with the reinforcing bars in the concrete slab. The anchor rod piles and the concrete slab jointly form the reinforced structure of the overlying shallow rockmass in the mined-out area. By adopting the method for reinforcing the overlying shallow rockmass in the mined-out area, the construction period of treating come-up foundations in the mined-out area is shortened, and the construction cost is saved. Moreover, the concrete slab and the grouting technology are comparatively mature, and are easy to implement in actual construction. The method for reinforcing the overlying shallow rockmass in the mined-out area can also be applied to the field of other soft foundation treatment projects.

Description

technical field [0001] The invention belongs to the technical field of civil engineering reinforcement, and in particular relates to a shallow layer reinforcement method of an overlying rock mass in a goaf. Background technique [0002] The goaf refers to the empty area left after the underground ore body is mined. Due to the mining of the ore deposit, various spaces (such as roadways and stopes) are formed in the rock and soil mass, which destroys the natural balance of the rock mass. The state changes the original stress field of the rock mass and produces a secondary stress field. Under the action of the secondary stress field, the overlying rock mass loses its original balance, resulting in movement, deformation and even destruction. The movement, deformation and destruction of the overlying rock mass in the goaf, in space, gradually expands from the goaf to the surrounding area and finally reaches the surface; in terms of time, it begins to move weakly from stillness, ...

AI Technical Summary

Problems solved by technology

First of all, due to the irregular shape and distribution of the underground empty area, it is difficult to fill the grout according to the established route during the actual grouting filling process, resulting in unpredictable filling effects in the empty area; secondly, due to the shrinkage of the grout, the grout is Bleeding and shrinkage occur during the solidification process, resulting in dissatisfaction in actual filling, and the smaller the cement content in the slurry, the greater the bleeding and shrinkage rate; finally, because the underground space is generally relatively large, the cost of grouting is huge

Moreover, grouting often has low work efficiency, long construction period and poor controllability.

Images