The effect of burnt rock on inclined shaft in shallow coal seam and its control technology

• Published in: Energy science & engineering Vol. 7; no. 5; pp. 1882 - 1895
• Main Authors: Yuan, Yong, Liu, Zhi‐Heng, Zhu, Cheng, Yuan, Chao‐Feng, Wang, Sheng‐Zhi
• Format: Journal Article
• Language: English
• Published: London John Wiley & Sons, Inc 01.10.2019; Wiley
• Subjects: advance pipe shed; burnt rock; Coal mining; Computer simulation; Control stability; Failure mechanisms; Fissure water; Fracture mechanics; Fractures; Geology; grouting reinforcement; inclined shaft; Integrity; Reinforcement; Restoration; Roads; Rock masses; Rocks; roof fall repair; Roofs; Shallow water; Shear strength; Strength; Theoretical analysis; Water storage; China
• ISSN: 2050-0505; 2050-0505
• DOI: 10.1002/ese3.398

Burnt rock is a geo‐material widely existed in many countries. After the rock mass is burned, the fracture is developed, the structure is destroyed, the integrity and strength are reduced, and a good water storage space is formed in suitable hydration conditions. In this paper, the roof fall characteristics and failure mechanism of inclined shaft in shallow water‐rich burnt rock area (SWRBRA) are analyzed using theoretical analysis, numerical simulation, and field measurement. It is revealed that the main factors causing the instability of surrounding rock on inclined shaft in SWRBRA are the deterioration of structure and integrity after rock mass is burnt, the weakening of surrounding rock strength under the action of fissure water, and the lagging support method. Therefore, the key measure to control the stability of surrounding rock in SWRBRA is to block cracks to eliminate the weakening effect of water and advance reinforcement to improve the surrounding rock strength. Through the comprehensive technologies such as rear roadway reinforcement, filling, and rebuilding artificial false roof and pipe shed advanced support, the effective restoration of the roof fall area in SWRBRA is realized. The surrounding rock fractures were closed, the strength of surrounding rock is improved by means of grouting reinforcement, and the stability control of surrounding rock of inclined shaft in SWRBRA is achieved. Burnt rock; Inclined shaft; Roof fall repair; Advance pipe shed; Grouting reinforcement.