金属矿中深孔微差爆破起爆延时精准识别与段别优化

Accurate Identification and Segmental Optimization of Detonation Delay in Mid-depth Hole Micro-differential Blasting in Metal Mining

爆破工程仍作为金属矿山矿石回采的主要方式,在岩体中深孔回采爆破过程中,空区围岩往往属于易受震动损坏的保护对象,为了使爆破震动的累计破坏控制在围岩能够承受的震动范围内,在进行爆破参数的设计和调整过程中有必要对空区围岩产生的震动进行控制。震动响应信号HHT分析方法具有依据数据本身时间尺度进行分解的特征,是一种自适应性的时频域局部化分析方法;IMFi模态函数可作为不同带宽下数字信号组成的固有分量,利用Hilbert-Huang变换得到每个模态分量的构造函数矩阵,针对构造函数建立instfreq.m函数瞬时频率调制算法,精准计算瞬时频谱、瞬时能量谱、Hilbert能量谱和三维时频能量谱。结合某金属矿山中深孔微差爆破震动实测数据,针对相邻两次中深孔爆破中的固定监测点进行爆破震动波形的精准识别,实现了多重判据下微差时间的精准识别和三维时频能量谱分析,给出了一种微差爆破起爆延时精准识别与段别优化方法,可为金属矿回采爆破中不同段别的识别改善、时频域能量的分布调控提供参考。

Blasting is still the main method of ore recovery in metal mines,and in the process of deep hole recovery blasting in rock mass,the surrounding rock in the void area is a protected object vulnerable to vibration damage,and in order to control the accumulated damage of blasting vibration within the vibration range that the surrounding rock can withstand,the vibration generated by the surrounding rock in the void area should be controlled in the process of blasting parameter design and adjustment.IMFi model function matrix can be used as the intrinsic component of digital signal composition under different bandwidths.In this paper,the Hilbert-Huang transform is used to obtain the constructor matrix of each modal component,and the instantaneous frequency modulation algorithm of instfreq.m function is established for the constructor.The instantaneous frequency spectrum,instantaneous energy spectrum,Hilbert energy spectrum and three-dimensional time-frequency energy spectrum are accurately calculated.Combined with the measured vibration data of medium-deep hole micro-differential blasting in a metal mine,the blasting vibration waveform is accurately identified for the fixed monitoring points in two medium-deep hole blasting.The HHT-instfreq algorithm is applied to realize the precise identification of micro-differential time under multiple criteria and the three-dimensional time-frequency energy spectrum analysis,and a method for the accurate identification and segment optimization of micro-differential blasting initiation delay is proposed.It can provide the basis for identifying and improving the different sections of metal mine.