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硬岩小净距隧道先行洞的爆破振动响应规律

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  • 国家科技期刊平台
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隧道爆破施工时，爆破破岩产生的振动效应对近邻隧道结构稳定性影响较大。为提高隧道爆破施工的安全性，基于广西某双线硬岩小净距隧道爆破开挖工程，通过现场爆破振动监测，分析后行洞爆破开挖时爆破振动的传播规律与质点峰值振动速度的分布特征，并利用有限元软件LS-DYNA建立相应的数值模型，探索近邻先行隧道径向和轴向上质点峰值振动速度演化特征及分布规律，基于最大主应力原则，构建近邻隧道爆破振动安全判据。研究结果表明:对后行隧道爆破开挖时，水平径向的振动波对近邻隧道的影响起主导作用;在爆心距相同的情况下，隧道未开挖侧的爆破振动衰减速度比已开挖侧的小;近邻隧道迎爆侧边墙、拱脚和底脚是主要受扰动区，边墙的质点峰值振动速度最大，在施工中应当加强边墙的监测和防护。基于近邻隧道质点峰值振动速度与拉应力内在联系的回归分析，并考虑混凝土的动态抗拉强度，建议将本隧道爆破施工的质点峰值振动速度阈值确定为15。7 cm/s，以保证依托工程近邻隧道支护结构的安全。
Response characteristics of blasting vibration of existing tunnel of hard rock neighborhood tunnel
During tunnel blasting construction process,the blasting vibration caused by the explosive impacts the stability of adjacent tunnel structures.To improve the safety of tunnel blasting construction,the double-line hard rock small spacing tunnel in Guangxi was taken as the engineering background.The vibration propagation and the peak particle velocity(PPV)distribution of existing tunnel were investigated during blasting of adjacent tunnel.The numerical model was established by dynamic finite element software LS-DYNA.The evolution process and distribution law of the PPV in the horizontal and vertical directions of adjacent tunnels were analyzed.The safety criterion of blasting vibration of adjacent tunnel was established based on the principle of the maximum principal stress.The result show that,during the blasting excavation of the working tunnel,the horizontal vibration plays an important role in impacting on the adjacent tunnel.When the explosion center distance is the same,the PPV attenuation rate of the unexcavated side of the tunnel is slower than that of the excavated side.The significant disturbed areas of the adjacent tunnel focus on the position of the side wall,arch foot and bottom foot,the monitoring and protection of side wall should be paid attention to in construction.Based on the regression analysis of the relationship between the PPV and tensile stress,considering the dynamic tensile strength of concrete,the PPV threshold is determined to be as 15.7 cm/s,which can ensure the safety of structure of the adjacent tunnel.

adjacent tunnelpeak particle velocityblasting vibrationspatial-temporal respouse

陈璐、曹洪涛、周子龙、曾铃、高山、刘洋、凌同华、聂森林

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长沙理工大学土木工程学院,湖南长沙,410114

中南大学资源与安全工程学院,湖南长沙,410083

广西新发展交通集团有限公司,广西南宁,530029

精细爆破国家重点实验室,湖北武汉,430056

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近邻隧道 质点振动峰值速度 爆破振动 时空响应

国家重点研发计划项目国家自然科学基金资助项目国家自然科学基金资助项目国家自然科学基金资助项目江汉大学省部共建精细爆破国家重点实验室、江汉大学爆破工程湖北省重点实验室联合开放基金资助项目

2022YFC2903901523340035200403652104111PBSKL2022D02

2024

10.11817/j.issn.1672-7207.2024.09.012

中南大学学报(自然科学版)
中南大学

中南大学学报(自然科学版)

CSTPCD北大核心
影响因子：0.938
ISSN：1672-7207
年,卷(期)：2024.55(9)