Dynamic caustics test of blast load impact on neighboring different cross-section roadways  

作　　者：Guo Dongming Zhou Baowei Liu Kang Yang Renshu Yan Pengyang 

机构地区：[1]School of Mechanics and Architecture Engineering, China University of Mining ＆ Technology, Beijing 100083, China [2]State Key Laboratory for Geomechnics ＆Deep Underground Engineering, Beijing 100083, China

出　　处：《International Journal of Mining Science and Technology》2016年第5期803-808,共6页矿业科学技术学报（英文版）

基　　金：provided by the National Natural Science Foundation of China (Nos. 51274204 and 51134025);National Key Basic Research Program (No. 2010CB732002);The Ministry of Education Program for New Century Excellent Talents to Support Project of China (No. NCET-12-0965)

摘　　要：Using digital laser dynamic caustics experimental system and conducting simulation experiment researched the influence rule of blasting excavation of a new roadway on neighboring existed different cross-section roadways. The experimental results show that the influence of blast load on adjacent roadway has a good relationship with the cross-section of roadway. The expansion distance of precrack existed in circular, arch-wall, rectangular roadway is respectively 1.76, 1.61 and 0 cm under blast load.At the same time, the direct-blast side of rectangular roadway has more obvious damage compared with circular and arch-wall roadway. It explains that plane reflects more stress wave than arc, so that it exerts more tensile failure in the direct-blast side, which leads to less stress wave diffracting to the precrack in the back-blast side. When the precrack extends, higher value dynamic stress intensity factor in circular roadway works longer than that of arch-wall roadway. Indirectly, it explains that plane's weakening function on stress wave is significantly stronger than arc. Stress wave brings about self-evident influence on the upper and bottom endpoints of the rectangular roadway, and it respectively extends 1.03, 2.06 cm along the line link direction of the center of the blasthole and the upper and bottom endpoints on the right wall.Using digital laser dynamic caustics experimental system and conducting simulation experiment researched the influence rule of blasting excavation of a new roadway on neighboring existed different cross-section roadways. The experimental results show that the influence of blast load on adjacent roadway has a good relationship with the cross-section of roadway. The expansion distance of precrack existed in circular, arch-wall, rectangular roadway is respectively 1.76, 1.61 and 0 cm under blast load.At the same time, the direct-blast side of rectangular roadway has more obvious damage compared with circular and arch-wall roadway. It explains that plane reflects more stress wave than arc, so that it exerts more tensile failure in the direct-blast side, which leads to less stress wave diffracting to the precrack in the back-blast side. When the precrack extends, higher value dynamic stress intensity factor in circular roadway works longer than that of arch-wall roadway. Indirectly, it explains that plane＇s weakening function on stress wave is significantly stronger than arc. Stress wave brings about self-evident influence on the upper and bottom endpoints of the rectangular roadway, and it respectively extends 1.03, 2.06 cm along the line link direction of the center of the blasthole and the upper and bottom endpoints on the right wall.

关 键 词：Dynamic caustics Blast load Different cross-section roadways Precrack Dynamic stress intensity factor 

分 类 号：TD263[矿业工程—矿井建设] TD235