Point source type spaced grouting damage reducing method by roof caving crack expansion filling and directional drilling

Abstract

The invention discloses a point source type spaced grouting damage reducing method by roof caving crack expansion filling and directional drilling. The method comprises the following steps of: after coal mining operation is carried out, a roof naturally caves to form a state of full filling or near-complete filling; firstly, spaced underground directional drilling is adopted to the upper part of acaving broken body, and a PVC (polyvinyl chloride) casing pipe and a grouting pipe are synchronously laid to realize fixed-point grouting, wherein the performance of a grouting material is selected by referring to a relevant national standard and is subjected to targeted mix proportion design, and a proper accelerator is selected to accurately control the initial setting time of grout; and then,a grouting flow meter and a grouting pressure meter are laid on a grouting pipeline to realize the accurate and real-time monitoring of a grouting quantity, and meanwhile, a spiral spray nozzle is selected to carry out surface-shaped injection grouting. Through grouting pipeline pressure control and flow monitoring, the grouting quantity and a grouting speed are determined, and finally, a point source type spaced grouting stack pile body layout scheme is formed.

Description

technical field [0001] The invention relates to the technical field of coal mine mining, in particular to a method for reducing damage by using roof collapse and swell filling and directional drilling point-source interval grouting. Background technique [0002] The status of coal as the core energy source in my country will not change in the short term, but with the increase of coal production in my country year by year, many mining damage problems have been brought about, which have a significant impact on the surface ecology and groundwater environment. Especially for the ecologically fragile area of ​​the Ordos Basin, where there is drought and little rain, water resources are scarce, and the ecological environment is fragile. The contradiction between large-scale mining of coal resources and ecological environment protection is very prominent. A large number of previous coal mining practices have shown that coal mining will change the distribution of the underground str...

AI Technical Summary

Problems solved by technology

However, the mining method of retaining coal pillars causes waste of resources and reduces the service life of the mine on the one hand; on the other hand, it affects the production layout and efficient coal recovery

However, the cost of filling mining is too high, and the economic benefit is poor, so it is not suitable for large-scale promotion and implementation of coal mining enterprises.

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