摘要
隧洞开挖过程中控制爆炸对岩体的损伤,减小爆破裂隙范围,对保证工程安全具有重要意义。基于爆炸应力波作用下爆生裂隙形成机制的研究,采用摩尔-库仑准则及最大拉应力准则,研究了初始地应力对爆炸应力波作用下爆生裂隙区比例半径的影响。研究结果表明,初始地应力对爆生裂隙范围有显著影响。在压剪破坏模式下,爆生裂隙区比例半径随地应力的增大而减小,地应力侧压系数影响爆生裂隙区比例半径在洞壁圆周的分布。考虑围岩应力卸荷影响后,沿隧洞径向的爆生裂隙区比例半径比不考虑卸荷的小。拉伸破坏导致的岩体爆生裂隙区比例半径一般比压剪破坏模式下爆生裂隙比例小,爆炸应力波作用下隧洞围岩更容易沿结构弱面发生压剪破坏。
To control the rock mass damage under blasting and to minimize the range of blasting cracks in tunnel excavation are of great significance for project safety. Based on the study of the forming mechanism of blasting cracks under blasting stress wave, using Mohr-Coulomb criterion and maximum tensile stress criterion, the proportional radius of blasting-induced cracking zone （PRB1CZ） affected by in-situ stress under blasting stress wave is studied. The study results indicate the PRBICZ is mainly influenced by in-situ stress. In compression and shear failure mode, the PRBICZ decreases with the increase of in-situ stress; the distribution of PRBICZ on tunnel wall is affected by side pressure coefficient of in-situ stress. If the unloading of surrounding rock stress is considered, the PRBICZ along radial direction of the tunnel wall is shorter than that without considering nature stress unloading. The PRBICZ in tensile failure mode is relatively shorter than that under compression and shear failure mode; compression and shear failure of the rock mass is more likely to occur along structure weak plane under blasting stress wave.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2009年第8期2254-2258,共5页
Rock and Soil Mechanics
基金
国家杰出青年科学基金(No.50725931)
国家自然科学基金资助项目(No.50779050)
国家自然科学基金委-雅砻江水电开发联合研究基金(No.50639100)
"十一.五"国家科技支撑计划项目(No.2008BAB29B01)
关键词
爆炸应力波
隧洞
岩体
地应力
裂隙
blasting stress wave
tunnel
rock mass
in-situ stress
crack
