高寒区冻岩爆破机理分析及力学特性试验研究

Analysis of Blasting Mechanism and Experimental Study on Mechanical Properties of Frozen Rock in Alpine Region

高海拔寒区矿山气温低,岩石常处于冻结状态,且上覆冻土层,爆破机理不明,爆破效果难以控制。将理论分析与室内试验相结合,分析了低温冻结条件下岩石爆破破碎机理及岩石主要力学参数变化规律。从非冻结岩石爆破破碎基本理论出发,阐述了岩石爆破破碎机理的3种较为流行的理论基础,分析了冻结岩石的爆破破碎机理。此外,开展了20℃、0℃、-5℃、-15℃、-30℃条件下岩石动静力学试验。结果表明,相同冻结温度下,岩石动态强度显著大于静态强度;随着温度的降低,岩石的动静态强度逐渐增大,岩石力学参数均呈现出线性相关关系;冻结条件下,岩石内部结构更为紧密,整体承载能力大幅度提升,岩石的爆破难度增大。研究结果可为高寒区现场爆破参数技术优化提供重要依据。

The temperature of mines in alpine region is low,and the rocks are often frozen,and are covered with frozen soil layer.The blasting mechanism is unknown,and the blasting effect is difficult to control.Combining theoretical analysis with laboratory tests,the mechanism of rock blasting fragmentation and the variation law of main mechanical parameters of rock under low temperature freezing conditions are analyzed.Based on the basic theory of non frozen rock blasting,this paper expounds three popular theoretical foundations of rock blasting crushing mechanism,and analyzes the blasting crushing mechanism of frozen rock.In addition,rock static and dynamic tests were carried out at 20℃,0℃,-5℃,-15℃and-30℃.The results show that under the same freezing temperature,the dynamic strength of rock is significantly greater than the static strength.With the decrease of temperature,the dynamic and static strength of rock gradually increases,and the mechanical parameters of rock show a linear correlation.Under freezing conditions,the internal structure of rock is more compact,the overall bearing capacity is greatly improved,and the blasting difficulty of rock is increased.The research results can provide an important basis for the technical optimization of on-site blasting parameters in alpine region.