摘要
为探究邻近巷道裂纹缺陷受爆炸荷载作用的扩展机理,采用透射式动态焦散线实验系统进行模拟实验。结果表明,对迎爆侧隐性裂纹,当裂纹与巷道左壁相对距离10 mm时,裂纹右尖端扩展因巷道的存在使预制裂纹导向作用更显著,引导爆生主裂纹与预制裂纹左尖端贯穿,衍射后作用于右尖端反射拉伸引起;对背爆侧隐性裂纹,当裂纹与巷道右壁相对距离4 mm时,裂纹扩展源于薄弱的巷道临空面将绕射的应力波能传递并导向裂纹缺陷,裂纹受拉扩展贯穿。巷道存在会增加其围岩裂纹缺陷处动应力集中,在爆炸应力波作用下会诱发裂纹扩展。
In order to explore the mechanism of extension of crack defects in nearby roadway under explosion load, a transmission type dynamic caustics experimental system was adopted to carry out the simulated experimental study. The experimental results show that the propagation of a prefabricated recessive crack located at meeting-blast side results from that the existing tunnel makes the leading effect of the prefabricated crack more notable, which guides the crack propagation from the explosive source to the left cutting-edge of prefabricated crack and by diffraction to the right cutting- edge, then the right cutting-edge starts to extend under the stretching influence of diffraction stress wave, when the distance between the prefabricated crack and the left panel of tunnel is 10 mm. For a prefabricated recessive crack at back-blast side, when the spacing between the prefabricated crack and the right panel of tunnel is 4 mm, the expansion of crack results from that the weak free surface of roadway guides the diffraction stress wave to crack defects, and then the crack extends under tensile stress. The existense of adjacent roadway increases the dynamic stress concentration at crack defects, inducing the crack extension under the effect of explosive stress wave.
出处
《振动与冲击》
EI
CSCD
北大核心
2016年第2期178-183,共6页
Journal of Vibration and Shock
基金
国家自然科学基金项目(51274204
51134025)
教育部新世纪优秀人才支持计划(NCET-12-0965)
关键词
爆炸荷载
邻近巷道
裂纹扩展
动态焦散线
explosion load
adjacent tunnel
crack propagation
dynamic caustics
作者简介
郭东明男，博士，副教授，1974年
