Method for determining hard roof working face deep hole pre-cracking forced roof caving parameter

Abstract

The invention discloses a method for determining a hard roof working face deep hole pre-cracking forced roof caving parameter. The method comprises the following steps of 1, determining the initial forced roof caving step distance of a basic roof rock stratum (3); 2, establishing a deep hole pre-cracking forced roof caving mechanical model; 3, constructing a relationship between the hard roof working face deep hole pre-cracking forced roof caving parameters; and 4, determining the value of the hard roof working face deep hole pre-cracking forced roof caving parameter. According to the characteristics of the initial mining pre-cracking fracture in the basic roof rock stratum, a deep-hole pre-cracking forced roof caving model is established, the initial breaking distance of the basic roof isdeduced by using a fracture mechanics theory, a deep-hole pre-cracking forced roof caving parameter is determined, and a theoretical reference is provided for a coal mine hard roof forced roof cavingparameter design research.

Description

technical field [0001] The invention belongs to the technical field of coal mine hard roof control, and in particular relates to a method for determining parameters of deep hole pre-splitting forced caving in a hard roof working face. Background technique [0002] The hard roof has the characteristics of high strength, no joints and fissures, and strong integrity. During coal seam mining, it is easy to form a large area of ​​overhanging roof. The sudden fall of the roof will cause strong pressure on the working face, resulting in "trunk", "hurricane", etc. Sudden accidents seriously threaten the safety of coal mine production personnel and equipment. Therefore, the control theory and technology of hard roof have been the key issues in mine pressure research. [0003] Chinese scholars have devoted themselves to the study of pressure control in hard roof mines since the 1950s. After more than 70 years of development, they have achieved a lot of results mainly in theoretical r...

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Problems solved by technology

[0004] Although the theoretical research on forced caving has made great progress, most of the design parameters of forced caving on site still adopt empirical values, and the effect of forced caving is difficult to control

Most of the basic roof mechanical models established for the forced caving during initial mining include vertical pre-cracks, and elastic mechanics is generally used to analyze the relationship between the pre-crack depth and the initial breaking distance of the basic roof. Fracture Mechanism of Rock Formation

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