Deep karst and structures characteristics and its surface regional exploration and treatment modes in the Huaibei and Huainan coalfields

ZHANG Haitao; XIE Zhigang; SUN Gui; XU Guangquan; YANG Yang; LIU Xing; LI Xu; HE Jianghui; XU Chengcheng

doi:10.11799/ce202504009

Abstract：Addressing the challenges of deep karst water hazard prevention in North China's concealed coalfields,we took the Huaibei-Huainan coalfield as a representative case.Through systematic analysis of deep karst development characteristics and structural evolution patterns,combining with decades of practical experience in karst water hazard detection and mitigation engineering,we established a ground-based regional exploration and treatment model for deep karst water hazards.The research findings demonstrate:① The Ordovician limestone in the Huaibei and Huainan coalfields has a big thickness,relatively strong water richness,and developed karst fractures,making it a key target for the prevention and control of deep karst water hazards.Karst fractures,karst collapse columns,and water conducting faults are important water conducting channels for karst water inrush,and they are also the focus of deep karst water hazard exploration and management.② The Carboniferous Taiyuan Formation is a key layer for the prevention and control of deep karst water hazards.Based on the differences in karst geological conditions and karst water hazard characteristics between the Huaibei and Huainan coalfields,the C33 limestone layer of the Taiyuan Formation is generally chosen as the target layer for grouting treatment in the Huaibei coalfield,while the C53,C73,and C93 limestone layers of the Taiyuan Formation are generally chosen as the target layer for grouting treatment.③ According to the different governance objects and ideas,the surface area exploration and governance projects in the Huaibei and Huainan coalfields can be divided into three typical modes,namely the karst fracture exploration and treatment mode,the fault exploration and treatment mode,and the karst collapse column exploration and treatment mode.Among them,the first one is a surface exploration and treatment mode,for which the treatment object is karst fractures.The second is a linear exploration and control mode,for which the treatment object is targeting faults(zones).The last one is a point like exploration and treatment mode,for which the treatment object is karst collapse columns.