A method for two-step pre-excavation of support and support withdrawal of a withdrawal channel

By using a step-by-step, two-stage pre-excavation and support withdrawal method, the stress reduction zone was scientifically and rationally determined, and a π-shaped roadway and broken-line support were designed. This solved the safety and efficiency problems of the pre-excavation withdrawal channel under advanced dynamic support pressure, and achieved safe and efficient equipment withdrawal.

CN115495884BActive Publication Date: 2026-03-31INNER MONGOLIA MANSHI COAL GRP CANZIGOU COAL CO LTD
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Patent Information

Application Number
CN202211027867.7
Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Filing Date
2022-08-25
Publication Date
2026-03-31
Estimated Expiration
2042-08-25

AI Technical Summary

Technical Problem

In existing technologies, pre-excavated retreat channels are prone to accidents such as crushing the coal pillars in the final mining section and killing the hydraulic supports under the influence of the advanced dynamic support pressure during the mining face. In addition, traditional pre-excavated retreat channels are time-consuming and labor-intensive, and the equipment retreat is unsafe.

Method used

The method of step-by-step pre-excavation and support and support withdrawal is adopted. The stress reduction zone of advanced mining is determined through scientific and reasonable calculation. The withdrawal channel is excavated in steps and coordinated support is carried out, including the support design of the advanced mining influence zone and the stress increase zone. Inclined π-shaped roadway and broken line pillars are used as support structures, combined with hanging diamond metal mesh to prevent roof collapse.

Benefits of technology

It enables safe and efficient tunnel excavation and support in the stress reduction zone, avoids the impact of premature mining at the working face, improves the safety and speed of equipment retreat, and reduces costs.

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Abstract

The application discloses a kind of back channel step two times pre-excavation support and support back method, comprising the following steps: (A) determining the range of stress reduction zone in advance mining;(B) support in advance mining influence zone;(C) excavate the back channel of first half, excavate transfer chamber and corner;Excavation is carried out simultaneously with the support of first half back space and the equipment of first half back;(D) excavate the back channel of second half, excavate transfer chamber and corner;Excavation is carried out simultaneously with the support of second half back space and the equipment of second half back.The present application is in advance according to support stress curve in stress reduction zone before stopping mining line, and the back channel is excavated in two steps on site, and the back channel is excavated and the support is shielded to realize the synergistic effect.
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