双向聚能拉伸爆破及其在硐室成型爆破中的应用

BILATERAL CUMULATIVE TENSILE BLASTING AND ITS APPLICATION IN SHAPING BLASTING OF CAVERNS

针对当前定向断裂控制爆破存在的问题 ,结合某特大型硐室成型爆破工程的地质、工程条件 ,利用岩石耐压而怕拉的特性 ,提出了双向聚能拉伸爆破技术。对该技术的特点、破岩机理、力学模型作了详细介绍与分析。进行了现场双向聚能拉伸爆破基础试验研究。在此基础上 ,该技术被应用于硐室的方形断面 (1个自由面 )和岩锚梁 (2个自由面 )的成型爆破。现场试验及应用结果表明 ,双向聚能拉伸爆破工艺简单、操作方便 ,能有效地控制裂纹产生、发展方向及断裂面的形成 ,实现岩体的精确控制爆破 。

The present paper aims at introducing a new controlled blasting technique of bilateral cumulative tensile explosion initiated by the author on the basis of defining the characteristics of the rock masses and their ability to resist high compression but easy to get fractured. Illustrating and analyzing all the so far existing problems in directional fracture controlled explosion, the author has found that when using the technology, the rock masses are mostly cracked as a result of the concentrated tensile stress due to the cumulative effect of the bilateral cumulative set specifically developed in bilateral cumulative tensile explosion. The paper has then given a detailed description of the merits and demerits of the present technique with the mechanism and mechanics models of the blasting being analyzed. Next, the author has also conducted a series of basic field experiments on the bilateral cumulative tensile explosion. In addition, he also carried out some shaping explosions of a rock rectangular cross-section (a rock window) with only one free surface and a rock bolt-beam profile(a rock bench) with two free surfaces in a cavern with satisfactory blasting results obtained. The results of experiments and the corresponding applications indicate that the technique enjoys outstanding features, such as simple procedure, easy operation and low cost. The whole process of initiation, propagation and arrest of cracks can be effectively controlled by the technique. The complex profile shaping blasting of rock masses with high uniaxial compressive strength can be effectively accomplished by using the present technique, whose promising applications can be seen from the presentation of the author's analysis of the related cases studies.