引水隧洞交叉段爆破振动对既有铁路隧道影响研究  

Study on the Influence of Blasting Vibration in the Crossing Section of Headrace Tunnel on the Existing Railway Tunnel

作　　者：马百庆 Ma Baiqing(Longquan Project Construction Service Center,Lishui 323799,Zhejiang,China)

机构地区：[1]浙江省龙泉市项目建设服务中心,浙江丽水323799

出　　处：《科技通报》2024年第3期71-78,共8页Bulletin of Science and Technology

基　　金：浙江省自然科学基金项目(LQ18E090003)。

摘　　要：针对交叉隧洞爆破施工对原有隧道安全运营的影响,本文以新建瑞垟引水隧道为依托,采用理论计算进行振动安全验算,确保钻爆施工产生的振动控制在确定的标准之内,进一步结合有限差分动力分析方法,研究下穿施工过程中既有隧道结构不同部位的应力分布特征和振动传播规律,之后依据工程监测数据,对理论分析和数值模拟结果进行验证分析。结果表明:新建隧道爆破施工不会对既有隧道结构安全构成威胁,爆源位置对即有隧道的振动响应影响显著,爆源位置在交叉点处时既有衬砌在爆点附近断面右拱脚处振动速度达到峰值4.43 cm/s,同一特征部位峰值振速由最大峰值断面向两侧衰减,且远爆源侧衰减更快,爆破开挖对后方已开挖区域的振动影响略大于前方未开挖区域,现场振动监测得出的振速分布规律与数值模拟计算结果相吻合,实测最大振速值均小于安全控制标准,研究成果可为类似上下交叉隧道工程振动安全控制提供参考借鉴。In view of the impact of cross tunnel blasting construction on the safety operation of the existing tunnel,based on the new Ruiyang diversion tunnel,this paper adopts theoretical calculation to check the vibration safety,to ensure that the vibration generated by drilling and blasting construction is controlled within the established standard,and further combines the finite difference dynamic analysis method.The particle vibration velocity and stress distribution of different parts of the existing tunnel structure in the process of underpass construction are studied.Finally,the theo-retical analysis and numerical simulation results are verified and analyzed according to the engineering monitoring data.The results show that the blasting construction of the new tunnel will not threaten the safety of the existing structure.The vibration response of the existing tunnel is closely related to the position of the explosion source.When the explo-sion source is located at the crossing point,the vibration velocity of the existing lining reaches a peak of 4.43 cm/s.The peak vibration velocity of the same characteristic part decays from the maximum peak fault to both sides,and the atten-uation is faster at the far explosion source side.The vibration effect of blasting excavation on the excavated area in the rear is slightly greater than that of the unexcavated area in the front.The distribution law of vibration velocity obtained by field vibration monitoring is consistent with the numerical simulation results.The maximum vibration velocity values measured are all lower than the safety control standard.The research results can provide reference for vibration safety control of similar upper and lower cross tunnel projects.

关 键 词：上下交叉隧道 钻爆施工 动力分析 振动特性 安全阈值 

分 类 号：TU447[建筑科学—岩土工程]