Prediction method for dynamic growth height of caving zone with immediate roof internally including structural rock stratum

Abstract

The invention relates to a prediction method for the dynamic growth height of a caving zone, and the method is suitable for height prediction of the caving zone of a large-mining-height working surface of a thick seam layer and is carried out under the condition that an immediate roof internally includes structural rock stratum. The method mainly comprises the following steps that a key layer is determined; the number of overburden layers is determined; when t1<tm', the key layer is positioned in a slit band, and a caving height is calculated to be H4; when tm'+1<ti, the structural rock stratum is positioned in the caving zone straightly, and a caving height is calculated to be H5; when ti+1<tj, the structural rock stratum is positioned in a bent sinking band, and a caving height is calculated to be H6; and when tj+1<tn, a height of the caving zone of a goaf in the total sinking period of the caving zone is calculated to be H7. According to the method, deadweight compressing performance and a time sequence of the caving zone and exploitation caused by that a caving space of the goaf is large are taken into consideration, dynamic distribution the caving zone is divided into four stages of analysis, calculation and prediction, the caving zone of the large-mining-height working surface can be reflected accurately, and basis is provided for support type selection, coal mining technology design, and top board flood damage control.

Description

Technical field: [0001] The invention relates to a method for determining the dynamic development height of caving zones in thick coal seams and large mining height working faces of coal mines, and is especially suitable for determining the dynamic development heights of caving zones in weakly cemented strata in the western and northwestern mining areas of my country. Background technique [0002] In the process of coal mining, the movement of rock strata above the stope is generally divided into three zones: caving, fracture and bending subsidence according to the range of movement and degree of damage. The caving zone refers to a penetrating fracture in the rock formation, and the rock blocks are piled up irregularly after falling. There is only gravity extrusion between the rock blocks, and the weight of the rock block accumulation needs to be fully borne by the lower support body. . The fault zone refers to the large amount of deformation of the rock formation above the...

AI Technical Summary

Problems solved by technology

[0005] The traditional empirical formula is only established with lithological strength as a single index, and the mining height and caving zone are linearly related; the height of the caving zone does not reflect the correlation with the mining time. In fact, the development height of the caving zone is closely related to time.

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