Typical model of water damage in Jurassic shallow coal seam mining and its zoning

Abstract

The mining of Jurassic shallow coal seam in northern Shaanxi coal base is faced with a variety of water hazards, and the traditional coal mine water hazard assessment has some limitations, so it is necessary to carry out more detailed water hazard model and zoning research in this area. Taking 3-1 coal seam of Hongliulin Coal Mine as the research object, we calculate the development height of water flowing fractured zone in coal mining, draw the contour map of development height of water flowing fractured zone, and propose the water disaster mode division method based on coal mine water disaster types by using the mutual position relationship between each aquifer and water flowing height, and divide different water disaster modes in the study area. The results show that: according to the different water filled aquifers(bodies) in the study area, the water damage types can be divided into three main water damage modes: single aquifer water damage mode, composite aquifer water damage mode and ancient Zhiluo river water damage mode. According to different water filling sources, the single aquifer water damage model can be divided into roof burnt rock water damage type and roof weathered bedrock water damage type; the composite aquifer water damage model can be divided into roof burnt rock direct-loose layer indirect water damage type, roof weathered bedrock direct-loose layer direct water damage type, roof burnt rock direct-loose layer direct water damage type and roof weathered bedrock direct-loose layer direct water damage type water damage type. The single aquifer water damage model is mainly distributed in the water flowing fracture zone, roof weathered bedrock aquifer and the area with hidden burnt rock aquifer above the mining coal seam; the composite aquifer water damage model is distributed in the water flowing fracture zone breaking through weathered bedrock aquifer, directly or indirectly affecting the loose aquifer area; the ancient Zhiluo river water damage model is distributed in the ancient Zhiluo river and the ancient river terrace. According to the analysis of the risk of water inrush under different water damage modes, the type of burning rock water damage generally does not pose a great threat to coal mining, and the risk of water inrush is small. Roof weathered bedrock water damage model, roof composite water damage model and ancient Zhiluo river water damage model are highly water-rich in some areas, and may enter the underground through the water conduction fault zone, so there is a certain risk of water inrush.

Keywords

• jurassic coalfield
• shallow coal seam
• water-conducting fracture zone
• typical water disaster model
• division of water disaster model