Status and remediation plan of groundwater system after mining in steeply dipping coal seam

HUANG Xiangkuan; HUANG Weiping

doi:10.19896/j.cnki.mtkj.2024.05.002

Abstract：Based on the theory of geology,mining science and hydrogeological engineering technology,through the understanding of the dissymmetry of surrounding rock disturbance after mining in steeply dipping coal seam,this paper studied and analyzed that the ground-water system after mining presented a variety of hydraulic connection forms,such as horizontal bedding,inclined bedding,horizontal cross layer,vertical cross layer and so on,especially the vertical hydraulic connection,which intensified the loss of groundwater above the erosion datum to the erosion datum below.Drawing on the techniques of water retaining coal mining and grouting interception,the technical scheme of repairing the groundwater system after mining in steeply dipping coal seam was put forward for the first time.Priority should be given to natural restoration in non critical areas,and the horizontal isolation zone should be regarded as the key area for engi-neering restoration,so as to realize the small area restoration of groundwater system and promote the restoration of large area.Especially for the horizontal level of the adit,engineering restoration should be carried out first,so as to promote the recovery of groundwater system above the erosion base level as soon as possible.In the aspect of engineering restoration,the method of injecting(pouring)interception was mainly adopted,the upward restoration or downward restoration was carried out,as well as the combination of the two ways,inject(pouring)slurry layer by layer and section by section to the caving and filling sections of the coal seam goaf,the damaged and disturbed sections of the roof and floor rock layers,after the reinforcement and reconstruction,the horizontal water separation(blocking)zone a-long the horizontal isolation coal pillar zone was formed,the vertical hydraulic connection of the groundwater system was reduced.Some suggestions for future research and practice were put forward.