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Coal Engineering ›› 2021, Vol. 53 ›› Issue (11): 73-80.doi: 10.11799/ce202111015

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Treatment technology of cavitary gob area based on high concentration cemented filling material

  

  • Received:2021-01-04 Revised:2021-04-20 Online:2021-11-20 Published:2022-01-05

Abstract:

Aiming at the problems of traditional cement slurry such as high bleeding rate, low stone rate, high dispersion of water material and high treatment cost, the high concentration cementing material filling treatment technology was put forward. In this paper, aeolian sand was used as the filling aggregate, and the physical and mechanical properties of high concentration cemented materials, such as strength, setting time, slump, stratification, bleeding rate and setting rate, were tested in laboratory. The material ratio that meets the strength and transportation requirements was selected. Based on the treatment of abandoned small kiln goaf under an industrial square in Northern Shaanxi Province, through drilling, drilling peeping and 3D laser scanning, the occurrence state and coal pillar distribution of goaf were found out, and the volume of cavities and voids in goaf was calculated quantitatively, which provided basis for accurate design of goaf. According to the results of the goaf exploration and the performance of the high-concentration cement material, the filling design and filling treatment were carried out. The three methods of comprehensive drilling core verification, filling solid strength test and site deformation monitoring were demonstrated, indicating that the high-concentration cement material filling reached design requirements for goaf treatment, while reducing the cost of filling materials by 32.5%, providing a new way for low-cost and efficient treatment of hollow voids.

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