FREEZING CROSS-CUT COAL CUTTING METHOD BASED ON HYDRAULIC SEAM-CUTTING

摘要

A freezing cross-cut coal cutting method based on hydraulic seam-cutting, comprising: constructing a plurality of water injection holes (5) on a coal cutting working surface (2) at a position where the minimum normal distance between the coal cutting working surface (2) and a coal layer (1) is greater than or equal to 7 m; employing a conventional hydraulic seam-cutting technique to perform hydraulic seam cutting on the water injection holes (5); after finishing the seam cutting, connecting the water injection holes (5) to a gas extraction pipe network and performing gas extraction; when the gas content of the coal layer is less than 8 m³/t, stopping the extraction; respectively constructing a freezing hole (7) and a temperature measuring hole (6) at two sides of the water injection hole (5); employing a capsule hole sealer (12) to seal a hole; injecting water into the coal layer (1) via the water injection hole (5), and closing a valve after finishing water injection; the water injected into the coal layer gradually seeps into a microfissure of a coal body; and employing a conventional freezing technique to freeze the coal layer around the water injection hole (5), free water in a fissure of the coal layer being gradually converted from a liquid state to a solid state in the freezing process, thereby improving the strength and anti-impact capability of the coal body, solidifying the coal layer, and enabling cutting of the coal layer according to a conventional coal cutting method.