大跨度小净距隧道爆破振动影响数值模拟分析

Numerical simulation of large span and small spacing neighborhood tunnel blasting vibration effect

结合温州绕城高速屏山隧道小净距段实际工况,应用数值模拟方法对小净距段在爆破荷载作用下的相互影响问题进行研究。研究结果表明:后行隧道爆破施工中应对先行隧道迎爆侧边墙处进行重点监控,且测点应尽量与爆源在相同高度处;对于3车道大断面小净距隧道,后行洞掌子面爆破最大段药量为30 kg时,先行洞二次衬砌发生拉伸破坏的潜在范围约为对应爆破掌子面前后10 m左右,为保证先行隧道二衬结构安全,先行隧道二衬浇注里程应滞后于后行隧道掌子面至少10 m距离以上。结论可为类似小净距段隧道的爆破设计、施工及现场监控量测提供一定参考。

Based on the actual situation of Wenzhou beltway Pingshan small spacing tunnel section,the interaction problem under blast loading in small spacing tunnel section was studies with the numerical simulation methods. The results showed that: the side wall of the ahead tunnel that near the blasting should be focused on monitoring during the blasting construction of the underwent tunnel; With three lanes large section and small distance tunnel hole,when the explosion of excavation of after hole is 30 kg,the potential scope of tensile fracture in secondary lining of leading hole is from ten meters after excavation. In order to ensure the safety of the ahead tunnel's secondary lining structure,the construction of the ahead tunnel's secondary lining structure should lags behind the tunnel face construction of the ahead tunnel for at least 10 m distance. The conclusions could provide some reference for the blasting design,construction and on-site monitoring and measurement of similar small spacing tunnel section.