定向爆破烟囱的回程应力波分析

AN ANALYSIS OF MOVEMENT STRESS WAVE OF A DIRECTIVE BLASTING OF A CHIMNEY

烟囱定向控制爆破倒塌过程中,有时会出现沿横断面折断断裂现象,为了弄清其产生的原因,利用运动行波的运动方程,求解不同起爆条件下行波的运动规律,以及不同时刻爆炸应力波在烟囱中所产生的应力作用行为和作用位置,发现了最大拉应力可能出现的时刻和位置,并拟合绘制出了最大拉应力的分布曲线。分别对100m高混凝土结构烟囱、80m高砖砌结构烟囱进行了对比计算分析,认为烟囱定向控制爆破的起爆宜采用低段别、短延期时差的起爆网路。

In process of a chimney directive blasting control, sometimes, a phenomenon that the chimney breaks off along its cross section appears. In order to clarify the reason why it occurs, equation of motion of movement wave is used to find its motion law under various detonation conditions, as well as stress behaviors and their acting positions produced by blasts at different instants. The time instant at which the maximum stretching stress may appear and its position are found, and its distribution fitting curve is drawn. A 100 m high concrete structure chimney, and a 80m high brickwork structure chimney as two examples are analyzed by using numerical simulation for comparison. It is concluded that the detonation net with lever segments and short time delay is suitable for detonation of a chimney directive blasting.