Determination and application study of optimal delay time for tunnel millisecond blasting based on interference vibration reduction method

Author:

Liu Chuanpeng1,Song Yanqi1ORCID,Shen Fuxin1ORCID,Zheng Junjie1,Shao Zhixin1,Yang Juntao1

Affiliation:

1. School of Mechanics and Civil Engineering, China University of Mining and Technology (Beijing), China

Abstract

In tunnel excavation, blasting is widely adopted as an efficient excavation method. However, the influence of vibration on tunnel surrounding rock and support structures during the blasting process cannot be ignored. In this study, based on the background of tunnel blasting construction, we theoretically analyze the reasonable range for selecting the optimal delay time, considering the wave superposition cancellation effect and rock fragmentation effect. We use field measured single-hole waveform and calculate superimposed predicted waveforms for different delay time through linear superposition. This allows us to determine the optimal delay time; it is then validated through numerical simulation and field experiment. The results indicate that, based on the principles of interference vibration reduction and rock fragmentation, the optimal delay time in theory should be in the range of 6.14–8.06 ms. By performing superposition calculation on the measured single-hole waveforms, we determined that the optimal delay time for continuous detonation of cut-holes is 7 ms. The delay time of 7 ms falls within a reasonable millisecond range and it is consistent with the results of numerical simulation. When the optimal delay time was applied to field blasting, the measured vibration waveforms exhibited uniform distribution. Compared to blasting without delay, the peak vibration velocity of the cut-holes decreased from 2.08 cm/s to 0.20 cm/s, and the dominant frequency band shifted from 20 Hz–60 Hz to 30 Hz–120 Hz. This achieved the desired effects of reducing vibration and enhancing frequency. These findings can serve as a reference for future similar engineering projects.

Funder

State Key Laboratory of Coal Resources and Safe Mining

National Key Research and Development Program of China

Publisher

SAGE Publications

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3