高地应力条件下爆破漏斗实验及数值模拟研究

Experiment and Numerical Simulation of Blasting Crater under High In-situ Stress

爆破漏斗最佳埋深是矿山爆破设计时的重要参数之一,随着开采深度不断向下延伸,开展高地应力条件下爆破漏斗相关研究对爆破设计及参数选取具有重要意义。以狮子山铜矿16中段的凿岩巷道为试验地点,在水平应力为25.5 MPa和垂直应力为21.1 MPa的岩体中开展了10个爆破漏斗试验,获得该区域爆破漏斗试验数据。同时,基于试验获得的最佳埋深,采用LS-DYNA软件建立三维爆破漏斗数值模型,获得了爆破后的漏斗形态及振动衰减规律。研究结果表明:爆破漏斗体积、半径等参数受地应力影响较大,爆破设计不能忽略地应力的影响;对现场爆破漏斗试验数据回归分析,得出爆破漏斗试验临界埋深为1.9 m、炸药最佳埋深为1.30 m、最佳埋深比为0.658;数值模拟结果与现场试验表现出了很好的一致性,可结合高地应力条件下的爆破漏斗数值模拟,为矿山的爆破设计提供基础参数。

The optimal buried depth of the blasting crater is one of the important parameters in the design of mine blasting.With the continuous downward extension of mining,the related research of the blasting crater under high in-situ stress is of great significance to the design and selection of blasting parameters.Taking the drilling tunnel in the middle section of Shizishan Copper Mine as the test site,10 blasting crater tests were carried out in the rock mass with the horizontal stress of 25.5 MPa and the vertical stress of 21.1 MPa,and the test data of blasting crater in this area were obtained.At the same time,based on the optimal buried depth obtained by the test,LS-DYNA software was used to establish a three-dimensional numerical model of blasting crater,and the morphology and vibration attenuation law of the crater after blasting were obtained.The results show that the parameters such as the volume and radius of the blasting hopper are greatly affected by the in-situ stress,and the effect of the ground stress cannot be ignored in blasting design.Regression analysis of blasting crater test data shows that the critical buried depth of blasting funnel test is 1.9 m,the optimal buried depth of explosive is 1.30 m,and the optimal buried depth ratio is 0.658.Numerical simulation results are in good agreement with the field test results,which can be combined with the numerical simulation of blasting crater under t high in-situ stress to provide basic parameters for mine blasting design.