GAO B B, REN C N, LI B B,et al.Research on in-situ protection technology of pressurized limestone water in the coal seam floor of North China-type coalfield from the perspective of resilience[J].Journal of Henan Polytechnic University(Natural Science) ,2024,43(4):12-20.

Received:2023/05/15

Revised:2023/09/11

Published:2024/07/05

Research on in-situ protection technology of pressurized limestone water in the coal seam floor of North China-type coalfield from the perspective of resilience

GAO Baobin1,2, REN Chuangnan1,2, LI Bingbing1,2, CHENG Lei1,2, SONG Shaopeng1,2, QI Zhihu3, XU Ying3

1.State Key Laboratory Cultivation Base for Gas Geology and Gas Control，Jiaozuo  454000，Henan，China;2.College of Safety Science and Engineering，Henan Polytechnic University，Jiaozuo  454000，Henan，China;3.Henan Yuzhong Geological Exploration Engineering Co.，Ltd.，Zhengzhou  450000，Henan，China

Abstract: Objectives To promote the high-quality development of water-preserved mining technology and effectively solve the problem of in-situ protection of pressurized limestone water in coal seam floor of the North China-type coalfield， Methods the whole process of resistance，recovery and re-adaptation of the coal seam floor under the influence of mining and pressurized water was analyzed from the three attributes of resilience（resistance，recovery，and adaptability）.According to the characteristics of system resilience evolution under disturbance，a technical framework for in-situ protection of pressurized limestone water in the coal seam floor of North China-type coalfields was proposed，with an emphasis on precision，efficiency，and comprehensiveness.This framework focused on the precise determination of the target area，efficient grouting of multi-branch wells，and comprehensive evaluation of water-preservation effects.   Results The results showed that the precise determination of the management target area included two aspects： vertical layer determination and lateral target determination.The efficient grouting of multi-branch wells included three steps： setting，drilling and injection.The comprehensive evaluation of the water conservation effect included two aspects： evaluation of the grouting effect on the coal seam floor rock layer and evaluation of the restoration of water resources’ carrying capacity.The vertical layer position of coal seam floor grouting was determined based on the calculation of the damage depth of the floor and the thickness of the critical water barrier layer.The lateral target position of floor grouting was determined based on the detection of key index parameters and the calculation model of the vulnerability index，forming a quantitative determination method and software system for the target area of floor grouting.Multi-branch well grouting combined with directional drilling technology was used to grout and seal relevant fissures，reducing the number of straight well sections and improving drilling efficiency.In terms of “safe mining” and “water resource protection” concepts in water-preserved mining，an in-situ water conservation effect evaluation method was proposed based on the detection of the grouting effect of the floor rock layer and monitoring the restoration of the water resource carrying capacity.  Conclusions The project had been applied in a mine in Anhui Province，ensuring the safety of coal seams mined on pressurized limestone water while balancing economic benefits and ecological environment development in the mining area.The research results had improved the technical system of water-preserved mining on pressurized water and provided references for subsequent research and field applications.  

Key words:resilience;North China-type coalfield;pressurized limestone water;water-preserved mining;grouting technology