大断面小净距隧道群爆破施工参数优化研究

Blasting Parameter Optimization in Tunnelswith Large Cross Sections and Small Clear-Spacing

以大帽山大断面小净距隧道为工程背景,理论分析、数值计算、设计和监测紧密结合,研究新建隧道爆破施工对邻近既有隧道的振动影响,进而实现对爆破参数的优化。现场监测结果表明,优化后爆破参数设计合理,该爆破设计在现阶段未对既有隧道安全产生较大影响。研究成果可为今后类似隧道工程的爆破施工提供参考借鉴。

The tunnels in Da Maoshan have large cross-sections and the clear-spacing between two tunnels is small. The tech niques of controlling blasting in the new tunnel construction while maintaining the stability and safety of the existing adjacent operating tunnels are studied in this paper. The vibrations induced by blasting during the new tunnel construction are moni- tored. The measured results are compared with the values from numerical simulations and theoretical analyses. The monitoring results indicate that the blasting design parameters can be optimized when the new tunnel construction is close to an existing one. This case study provides a theoretical approach as well as practical experience in safeguarding the existing operating tun nels while blasting in the adjacent new tunnels.