Method of local filling to control surface subsidence in gob

Abstract

A method of local filling to control surface subsidence in a gob. Metal nets are suspended at intervals from open-off cuts and on top plates behind a hydraulic bracket on a working surface along with coal cutting of a coal cutter and movement of the hydraulic bracket on the working surface, and filling bags are arranged; coal cutting is stopped after cutting is performed once by the coal cutter, and concrete is filled into the filling bags in the metal nets in sequence until a roof; cutting is continuously performed once by the coal cutter, metal nets are continuously suspended on top plates adjacent to the two sides of the filled area, filling is continuously performed to complete a filling cycle, and a row of filled bodies are formed in a gob parallel to the working surface; and coal cutting is continuously performed four to five times by the coal cutter, the following filling cycle is completed continuously, and the procedures are repeated until filling of the whole gob is completed and a plurality of rows of filled bodies are formed in the gob. The method is simple, and the filling cost is low. The top plates in the gob are supported uniformly at intervals; therefore, the stability of an overburden layer, in particular a key layer, can be improved, and surface subsidence and damage to buildings can be effectively prevented.

Description

technical field [0001] The invention relates to the technical field of coal mining, in particular to a method suitable for "three-down" pressure coal mining in mines and local filling of goafs with relatively stable coal seam roofs to control surface subsidence. technical background [0002] my country's production mines have "three down" coal pressures of about 14 billion tons, which can be used for 140 years for 10 mines with an annual output of 10 million tons, of which the coal pressure under buildings is about 9 billion tons. How to reasonably solve the problem of coal mining under buildings has always been one of the important issues perplexing Chinese coal mining enterprises. [0003] For post-mining ground subsidence control, domestic and foreign mainly start from two aspects: subsidence reduction mining and goaf roof movement control: [0004] Subsidence reduction mining technology mainly includes strip mining and room-and-pillar mining. Strip mining is to divide t...

AI Technical Summary

Problems solved by technology

The separation layer grouting technology starts from the internal movement law of the rock formation, determines the position of the separation layer of the overlying rock after mining, and fills the medium such as fly ash into the separation layer from the surface drill hole, so as to achieve the purpose of controlling the surface subsidence. Grouting and underground mining operate in parallel without interfering with each other, but the application is limited due to the difficulty in accurately judging the position and amount of separation

The grouting filling technology in the caving area is to inject grout for filling and reinforcement before the caving gangue in the goaf is compacted, so as to support the overlying rock and slow down the surface subsidence. This technology is still in the research stage and has not been widely used.

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