含软弱夹层岩体爆破的夹层土运动特征试验研究

 以单孔台阶爆破为原型，进行含软弱夹层的混凝土模型爆破试验，利用高速摄像观测爆破过程中夹层土的运动状态，分析不同炮孔装药量、夹层土含水率和最小抵抗线条件下夹层土的运动特征及其变化规律。研究结果表明，利用高速摄影可以清晰地观测到距炮孔中心2～4 cm之后的夹层土的运动影像，从而证实爆破对紧邻炮孔的软弱夹层的推移作用；模型爆破时夹层土的最大运动速度可达450 m/s，并随着与爆心距离的增大，夹层土的运动速度大致呈线性降低，其降低幅度主要受夹层土含水率和炮孔装药量的影响；距炮孔相同距离处的夹层土运动速度和运动的最大距离均随装药量、含水率、最小抵抗线的增加而增大，且装药量对夹层土的最终推移距离起着主要作用。

EXPERIMENTAL STUDY OF MOTION CHARACTERISTICS OF WEAK INTERCALATION IN ROCK MASS BLASTING

Taking one-hole bench blasting as prototype，the blasting experiment of concrete models with a weak intercalation is carried out. The motion state of intercalation in blasting process can be observed using high-speed digital camera，and the motion characteristics of intercalation and variation laws under the conditions of different charges，moisture contents and the minimum burdens are analyzed. The research results show that the clear motion images of intercalation more than 2–4 cm away from blast-hole center can be obtained by high-speed digital camera，which confirms the pushing action of blasting upon the weak intercalation adjacent to blast-hole；the maximum motion velocity of intercalation in concrete model blasting can reach 450 m/s；and with the increase of the distance from the blast-hole center，the motion velocity linearly decreases approximately and its decrease range is mainly affected by the moisture content and charge；the motion velocity of intercalation and the maximum motion distance increase with the increase of charge，moisture contents and the minimum burden；moreover，the charge plays an important role in the final motion distance of intercalation.