摘要
针对深埋圆形隧洞爆破开挖,采用LS-DYNA数值模拟方法,研究了不同地应力水平下爆破荷载作用产生的围岩损伤分布、PPV衰减规律以及岩体爆破损伤对应的PPV阈值。研究结果表明:在地应力水平较低的情况下,围岩损伤主要由爆破荷载引起,岩体表现为张拉损伤破坏;随着地应力水平的提高,围岩损伤范围减小,岩体爆破损伤的PPV阈值增大;当地应力水平达到足以引起岩体损伤破坏时,随着地应力水平的进一步提高,围岩损伤范围增大,岩体爆破损伤的PPV阈值呈减小的趋势。因此,深埋隧洞开挖的爆破振动安全控制标准须考虑地应力的影响。
For blasting excavation of a deep circular tunnel,the distribution of the rock damage caused by blast loading under different in-situ stress levels was studied by using a numerical simulation method based on the software LS-DYNA.The peak particle velocity(PPV)attenuation associated with blasting was subsequently investigated to acquire the PPV thresholds for blast-induced rock damage under different in-situ stress levels.The results show that at lower in-situ stress levels,the damage in the surrounding rock is mainly caused by blast loading in tension mode.As the in-situ stress increases,the blasting damage extent into the tunnel profiles is reduced and the PPV thresholds are accordingly increased.When the in-situ stress reaches a value high enough to cause rock damage due to stress redistribution,the damage extent turns to increase and the PPV thresholds begin to decrease with the further increase in in-situ stress levels.Therefore,the influence of the in-situ stress on rock damage should be considered in the blasting vibration standards with respect to deep tunnel excavation.
作者
陈奕阳
杨建华
蔡济勇
姚池
CHEN Yi-yang;YANG Jian-hua;CAI Ji-yong;YAO Chi(School of Civil Engineering and Architecture,Nanchang University,Nanchang 330031,China)
出处
《爆破》
CSCD
北大核心
2018年第4期34-39,共6页
Blasting
基金
国家自然科学基金项目(51509126
U1765207)
江西省自然科学基金项目(20161BAB206127)
江西省教育厅科学技术研究重点资助项目(GJJ150030)
