Measuring method and risk assessment method of head-on stress in coal roadway excavation

Abstract

The invention proposes a coal roadway driving head-on stress measuring method and danger assessment method. The coal roadway driving head-on stress measuring method comprises the steps: setting drill holes with different depths in a vertical direction at a coal roadway driving head-on side from one end; placing FBG (fiber bragg grating) sensors at tail ends of all drill holes; obtaining the stresses at the tail end of all drill holes through an FBG monitoring system; plotting a stress distribution curve; and stopping the drilling when the stress distribution curve is observed to be horizontal. The coal roadway driving head-on danger assessment method comprises the steps: obtaining the adjacent stress distribution curves through the coal roadway driving head-on stress measuring method; predicting the maximum stress value in a virtual third stress distribution curve at a remoter position; and comparing the maximum stress value with the maximum total stress of a coal body. The beneficial effects of the invention are that the methods can obtain the stresses at different positions and distances in front of a driving head; and the methods provide basis for the application of the driving speed of a driving work surface and the related danger removing measures.

Description

technical field [0001] The invention relates to the technical field of early warning and prevention of coal mine disasters, in particular to a method for measuring head-on stress in coal roadway excavation and a risk assessment method. Background technique [0002] Coal-rock dynamic disasters are characterized by rapid onset and great harm, which seriously threaten the safe and efficient mining of coal in my country and become one of the most serious forms of disasters. It can be seen from relevant literature that coal-rock dynamic disasters mainly occur at the head-on position of excavation. Since roadway excavation is often excavated in an area where the coal-rock environment is relatively unknown and affected by various factors, accident prevention and control is more difficult. In addition, man-made excavation activities cause uneven stress on the coal body ahead of the excavation, which is also an important inducing factor for coal-rock dynamic disasters. Specifically,...

AI Technical Summary

Problems solved by technology

In the existing technology, there is no good solution to the stress measurement inside the coal body, and the stress at different distances and positions in front of the tunnel cannot be obtained in real time.

There is no suitable risk assessment method for coal roadway head-on in the prior art, which cannot provide a basis for the advancement speed of the tunneling face and the application of related risk-relief measures

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