隧道楔形掏槽爆破延期时间优化与现场试验研究  

Delay Time Optimization and Field Test for Wedge Cut Blasting in Tunnel

作　　者：汤智力 TANG Zhili(China First Highway Engineering Co.,Ltd.,Beijing 100024,China)

机构地区：[1]中交一公局集团有限公司,北京100024

出　　处：《施工技术(中英文)》2024年第24期25-30,共6页Construction Technology

基　　金：爆破工程湖北省重点实验室开放基金(BL2021-23)。

摘　　要：为探究楔形掏槽爆破延期时间对破岩成腔效果与振动的影响规律,依托松山隧道工程,基于毫秒延期爆破技术,采用数值模拟与现场试验相结合的方法,研究了掏槽孔对间不同延期时间(Δt=0,5,10,15ms)对隧道楔形掏槽爆破效果的影响。研究结果表明:爆破振动峰值随延期时间的增大呈逐渐降低趋势。同时,相较于同时起爆,观测点在不同延期条件下降振率变化在20.74%~34.46%,变化速率呈先快后慢趋势;岩体的损伤随延期时间的增大呈逐渐降低的变化趋势,振动速度峰值呈先降低后趋于稳定的变化趋势;当掏槽孔对间延期时间为5~10ms时,可在一定程度上控制应力波的叠加,使得其在空间和时间上相互错开,在降低爆破振动幅值的同时,能保持掏槽区的损伤效果;现场试验表明,在改变掏槽孔对间延期时间的条件下,设置对间延期时间为8ms时,隧道掘进爆破炮孔利用率提高15.1%,爆破效果得到显著改善。In order to explore the influence of the delay time of wedge cut blasting on the effect of rock breaking and cavity formation and vibration,in this paper,based on Songshan Tunnel project,the influence of different delay time(Δt=0,5,10,15ms)between the cutting holes on the wedge cut blasting effect of the tunnel is studied by the combination of numerical simulation and field test with the millisecond delay blasting technology.The results show that:The peak value of blasting vibration decreases gradually with the increase of delay time.At the same time,compared with the simultaneous initiation,the vibration rate of the observation point decreases in the range of 20.74%~34.46%under different delay conditions and the change rate shows a trend of first fast and then slow;The damage of rock mass decreases gradually with the increase of delay time and the peak value of vibration velocity decreases first and then tends to be stable.When the delay time between the cutting holes is 5~10ms,the superposition of stress waves can be controlled to a certain extent,so that they are staggered in space and time,and the damage effect of the cutting area can be maintained while reducing the amplitude of blasting vibration;The field test shows that under the condition of changing the interval delay time of the cutting hole,when the interval delay time is set to 8ms,the utilization rate of the blasting hole in the tunnel excavation increases by 15.1%and the blasting effect is significantly improved.

关 键 词：隧道 爆破 楔形掏槽 延期时间 数值模拟 试验 

分 类 号：U455[建筑科学—桥梁与隧道工程]