A Method for Determining Parameters of Deep Hole Pre-cracking Forced Caving in Hard Roof Working Face

Abstract

The invention discloses a method for determining a forced caving parameter for a deep hole pre-split on a working face of a hard roof. The method comprises the following steps: step 1: determining the initial forced caving step distance of a basic top rock layer (3); step 2, establishing The mechanical model of forced caving for deep hole pre-splitting; Step 3: Construct the relational expression between the parameters of forced caving for deep hole pre-splitting in the working face of hard roof; . According to the characteristics of the initial mining pre-split cracks in the basic top rock layer, the invention establishes a deep hole pre-split forced roof caving model, uses the fracture mechanics theory, deduces the initial breaking distance of the basic roof, determines the deep hole pre-split forced roof caving parameters, and is a coal mine. A theoretical reference is provided for the design and study of the parameters of the forced caving of the hard roof.

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...

AI Technical Summary

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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