为了分析爆炸动荷载对巷道围岩不同位置处缺陷扰动的影响,采用爆炸加载透射式动焦散试验方法进行了相关试验研究。试验结果表明:在爆炸动荷载作用下,位于巷道顶端的竖直裂纹最易扩展,拱部和底角处倾斜裂纹较易发生扩展,巷帮处水平裂纹不易扩展,扩展位移分别为31,17,20,6 mm;裂纹扩展位移的大小与应力强度因子值密切相关,巷道顶部裂纹KⅠ值最大,拱部和底角处倾斜裂纹的KⅠ值次之,巷帮处水平裂纹的KⅠ值最小。上述研究成果对减少爆破动载荷对围岩的扰动和损伤、节约围岩的支护成本、保证安全施工和快速施工有重要意义。
In order to analyze the influence of the blasting dynamic load on defects extension of roadway surrounding rock in different locations, the explosion load system using dynamic reflected caustics has been used to conduct the organic glass model experimental study. The experimental results have shown that under the influence of dynamic load the vertical crack at the top of the roadway is easier to extend than others, then are the inclined cracks at the arch and the corner,and the last ones are the horizontal cracks with the data of cracks propagation length of 31,17,20 and 6 mm respectively. The value of the displacement of crack propagation has a direct relationship with the value of the stress intensity factor and we can see that the value of the stress intensity factor of the vertical crack at the top of the roadway is greater than that of other three cracks, then is the value of the inclined cracks at the arch and corner and the value of the horizontal crack is at the minimum level. The above research results have positive influence on reducing the disturbance and damage of the blasting dynamic load on surrounding rock, and on saving the cost of surrounding rock supporting, ensuring construction safely and rapidly.