Rock's mechanical parameters and fragmentation characteristics significantly change under the freez-ing and thawing environment in high-altitude cold regions,and it is difficult to directly apply traditional blasting pa-rameters for excavation.Therefore,researching blasting design parameters in freeze-thaw environments is of great im-portance.This study analyzed the impact of freeze-thaw cycles on rock mechanical properties and conducted the cra-ter experiments of single-hole and double-hole simultaneous blasts in ore rocks under freeze-thaw conditions based on Jurong Copper mine.Futhermore,the geometric parameters and block size distribution of the crater were measured af-ter blasting,and the reasonable parameters for blasting design were determined using the mathematical fitting meth-ods.Additionally,the changes in the blasting crater parameters of the mine were also compared and analyzed under four different rock conditions.The results show that the mechanical properties of rock mass significantly deteriorate with a decrease in uniaxial compressive strength and elastic modulus of up to 40.6％and 54.0％under freeze-thaw cycles,respectively.The optimal burial depth ratio for single-hole blasting of freeze-thaw ore rocks is 0.678～0.789 under different lithological conditions,and the ratio of the optimal charge burial depth to crater radius is distributed in the range of 0.875～1.076.For Chibula mining area,the hole diameter is 152 mm,the diorite hole net parameter is 4.5 m×3 m,the corresponding explosives consumption is 0.56 kg/m3,and the tuff hole net parameter is 5 m × 4 m with a 0.63 kg/m3 explosives consumption.For Jurong mining area,the hole diameter is 310 mm,the tuff blas-ting hole net parameter and explosive consumption is respectively 7 m ×5 m and 0.61 kg/m3,and the granite por-phyry hole net parameter and explosive consumption is respectively 8 m ×5 m and 0.64 kg/m3.
关键词
高寒地区/冻融环境/岩体爆破/爆破设计参数/物理力学特性/爆破漏斗试验
Key words
high-altitude cold region/freeze-thaw environment/rock blasting/blasting design parameters/physical and mechanical properties/blast crater test
维普
万方数据