Study On Risk Analysis And Treatment Scheme Of Goaf In Traditional Mining Areas Of Hebei Province

Hebei Province,with its wide distribution of mineral resources and obvious regional characteristics,is a big province of mining resources development.However,the rapid development of mines has brought many problems,including the formation of a large number of mined-out areas,the destruction of ecological environment and frequent geological disasters.Goaf hazard is one of the main hazards in mines.It is of great significance to establish an effective evaluation system for goaf risk and classify goaf risk levels for better realizing"hierarchical control and highlighting key points"and ensuring the sustainable development of mining enterprises.On the basis of investigating a large number of documents at home and abroad,this paper analyzes and summarizes the research progress,existing problems and development direction of risk assessment of underground goaf,and studies the risk analysis and treatment scheme of goaf in traditional mining areas on the basis of system engineering theory,risk assessment theory and overall risk management theory,and obtains the following research results:（1）Taking the mined-out area in a mining area of XTXK Iron Mine as the research object,based on the in-depth analysis of mine engineering data,the present situation of the mined-out area was fully investigated,and the main risk types and influencing factors of the mined-out area were identified by using the collective interview method.（2）The risk index system of three primary risk evaluation indexes,i.e.,ground conditions,goaf characteristics and geological conditions,and 13 secondary risk evaluation indexes（ground facilities,surrounding personnel,goaf size,goaf formation time,surrounding workers,goaf buried depth,blasting vibration,pillar setting,goaf connectivity,orebody dip angle,geological structure,surrounding rock characteristics and rock mass structure）is determined.The AHP method is used to calculate and determine the weight of 13 risk evaluation indexes in goaf,and the weight of each risk evaluation index is sorted According to the characteristics of mined-out areas,the risk assessment indexes of mined-out areas in a mining area of XTXK Iron Mine are divided into four grades:A,B,C and D.（3）According to the established risk index system,30 experts were hired to score each risk evaluation index by questionnaire survey method,and the survey results were statistically analyzed.Finally,the comprehensive risk membership degree of goaf in a mining area of XTXK Iron Mine was calculated by using fuzzy comprehensive evaluation method.According to the principle of maximum membership degree,the goaf risk is general risk,and special treatment should be carried out according to the needs of production and other operations.（4）According to the evaluation results of each grade risk index system,special treatment measures are put forward for the mined-out area of a mining area in XTXK Iron Mine.Among the first-level risk assessment indicators,the empty area feature（B₂）has the highest risk,and its weight is 0.5826;Among the secondary risk indicators,the risk weight of personnel is the highest,among which the weight value of ground personnel(C₁₂)is 0.7643,and the weight value of workers around the goaf(C₂₂)is 0.4006.According to this,the measures of goaf treatment mainly include filling goaf to reduce the size of goaf,closing and isolating goaf to reduce personnel entering or approaching goaf,covering soil and greening after treatment of open goaf,and building reservoir in low-lying area of mining area.The research goal of this project is to establish a scientific and effective risk assessment system for goaf of traditional mining areas in Hebei Province.By effectively identifying each risk index,the risk evaluation index system is constructed,and the AHP method is used to calculate the weight of each grade index in goaf,and the fuzzy evaluation method is used to quantitatively evaluate the overall risk of goaf.According to each grade risk and comprehensive risk evaluation score,combined with the present situation of goaf risk management,the risk management scheme for goaf in a mining area of XTXK Iron Mine in Hebei Province was formulated.This result provides some reference for risk management of goaf in traditional mining areas of Hebei Province.