煤矿安全2025，Vol.56Issue(8)：69-77,9.DOI:10.13347/j.cnki.mkaq.20250270
基于SF6气体示踪的爆破孔致裂半径确定方法
A method for determining fracturing radius of blasting holes based on SF6 gas tracing
摘要
Abstract
The fracturing radius,as a key indicator characterizing the energy transfer of mine blasting and the fragmentation effect of rock mass,its precise determination is directly related to the safety and energy efficiency of blasting engineering.However,due to the heterogeneity of complex geological structures,the irreversibility of the dynamic crack evolution mechanism and the limitations of in-situ monitoring technology,there are still significant technical bottlenecks in the in-situ detection of the fracturing radius at present.Aiming at this engineering problem,based on the unique chemical inertness,strong diffusion characteristics and highly sens-itive detection advantages of sulfur hexafluoride(SF6)gas,an in-situ dynamic detection method based on the tracer principle of SF6 gas is proposed,and a multi-module coupled crack radius detection system is developed.Combined with the migration law of gas diffusion concentration in three-dimensional space,the quantitative relationship between the SF6 diffusion field and fracture develop-ment is identified.This system integrates the gas supply unit(SF6 storage tank and pressure stabilizing control),the adaptive sealing component(with a pressure resistance of 2.5 MPa),and the distributed gas detection array(detection accuracy of±0.1×10-6),and forms a closed tracer gas circulation monitoring system through airtight pipelines,burst holes,and observation holes.In-situ blasting cracking tests were carried out at the 10102 top extraction roadway excavation face of Yuwang Coal Mine.The spatial concentration gradient analysis method was adopted to establish a quantitative evaluation model of SF6 diffusion field and cracking radius.The res-ults show that:when the volume fraction threshold of SF6 was set at 150×10-6,the effective fracturing radius of the blast hole reached 1.0 m(confidence interval±0.15 m),and its asymmetric distribution characteristics were significantly correlated with the geological structure.Engineering verification shows that after optimizing the blasting parameters based on this detection result,a 17%reduc-tion in the charge per hole can still meet the fracture propagation requirements,verifying the engineering applicability of the system.关键词
爆破致裂/爆破孔/致裂半径/SF6气体/示踪原理/煤岩裂隙发育/煤层气储层改造Key words
blasting and cracking/blasting hole/crack radius/SF6 gas/tracing principle/coal and rock fractures development/coal-bed methane reservoir modification分类
矿业与冶金引用本文复制引用
贾东旭..基于SF6气体示踪的爆破孔致裂半径确定方法[J].煤矿安全,2025,56(8):69-77,9.基金项目
国家自然科学基金联合基金资助项目(U23B2094) （U23B2094）
