小净距隧道爆破振动规律研究--以石尾隧道为例

Study on the Vibration Law of Small-interval Tunnel-Take Shiwei Tunnel as An Example

小净距隧道具有造价相对较低、有利于整体线性优化等优点,在公路短隧道设计中被广泛采用。小净距隧道施工工艺相对连拱隧道较为简单,但鉴于隧道的中岩墙厚度相对较小,在采用钻爆法施工过程中,爆破不仅会影响掘进隧洞围岩稳定性,亦会对相邻隧洞结构稳定性产生一定影响,进而影响隧道施工安全。本文以在建小净距石尾隧道为例,在先行洞右洞掌子面爆破施工时,通过对左洞距爆破掌子面不同距离测点进行爆破振动测试,研究了左洞围岩及其结构在爆破振动后的振动波速变化规律。根据爆破振动监测结果及分析可动态调整爆破方案与参数,确保爆破施工安全性。石尾隧道的爆破振动规律研究成果对公路小净距短隧道的爆破施工具有一定参考意义。

Small-interval tunnel is widely used in the design of highway short tunnel because it has the advantages of relatively low cost and conducive to overall linear optimization. The construction process of small-interval tunnel is simpler than that of the double-arch tunnel. However, in view of the relatively small thickness of middle rock wall in the tunnel, in the construction process of drilling and blasting method, blasting will not only affect the stability of surrounding rock of tunneling tunnel, but also has a certain impact on the structural stability of adjacent tunnels, and further affects the safety of tunnel construction. Taking the small-interval tunnel Shiwei tunnel as an example which is under construction, during the blasting construction of the right tunnel, through the blasting vibration test of the left tunnel according to the measuring points at different distances from the blasting face, the variation law of vibration wave velocity of the surrounding rock and its structure of the left tunnel after blasting vibration is studied.According to the monitoring results and analysis of blasting vibration, the blasting scheme and parameters can be dynamically adjusted to ensure the safety of blasting construction. The research results of blasting vibration law of Shiwei tunnel have certain reference significance for the blasting constructionofhighwaytunnelwithsmallcleardistanceand shortdistance.