小净距隧道掘进爆破及其振动响应规律研究  

Study on Attenuation Law of Blasting Vibration in a Small Clear Distance Highway Tunnel

作　　者：李小帅[1] 高文学[1] 宿利平 张小军[1] 胡宇[1] 薛睿 LI Xiao-shuai;GAO Wen-xue;SU Li-ping;ZHANG Xiao-jun;HU Yu;XUE Rui(Faculty of Architecture,Civil and Transportation Engineering,Beijing University of Technology,Beijing 100124,China;Beijing Municipal Road and Bridge Co.,Ltd.,Beijing 100045,China)

机构地区：[1]北京工业大学城市建设学部,北京100124 [2]北京市政路桥股份有限公司,北京100045

出　　处：《爆破》2024年第2期194-202,共9页Blasting

基　　金：爆破工程湖北省重点实验室开放基金(BL2021-23)。

摘　　要：为了研究爆破荷载作用下小净距隧道中夹岩区的动力稳定性问题,依托小龙门隧道爆破工程,开展了现场爆破振动监测试验。通过改进的变分模态分解(variational mode decomposition,VMD)与多尺度排列熵(multi-scale permutation entropy,MPE)算法对爆破振动信号进行消噪处理,基于此分析了掏槽孔与周边孔爆破在后行洞左拱腰(非中夹岩区)、右拱腰(中夹岩区)中产生的振动特征差异。结果表明:采用改进的自适应VMD-MPE算法可以有效消除振动信号中的噪声,并降低了主观决策的影响;此外,相对于非中夹岩区,中夹岩对爆破振动具有明显的放大效应,其质点峰值振速明显大于非中夹岩区,但中夹岩区的振动衰减速度更快;同时,通过对比非中夹岩区与中夹岩区各测点振动频率特征可以发现,中夹岩区小于40 Hz的低频振动能量占比较大,更易引起支护结构的共振,发生损伤与破坏的风险更高,应重点关注;受“转角削弱”作用以及地震波传播路径的影响,在比例距离SD小于等于11.57 m·kg^(1/3)范围内,周边孔爆破在掌子面后方围岩中产生的振速大于掏槽孔。In order to study the vibration response of the interlaid rock in the small clear distance tunnel under the blasting load,a field blasting vibration test was carried out based on the blasting project of the Xiaolongmen tunnel.The improved variational mode decomposition(VMD)and multi-scale permutation entropy(MPE)algorithm were employed to denoise the blasting vibration signal.Subsequently,the differences in vibration characteristics between the left arch waist(non-interlaid rock area)and right arch waist(interlaid rock area)of the tunnel were analyzed,along with a comparison and analysis of seismic wave attenuation characteristics generated by cut hole blasting and surrounding hole blasting.The results demonstrate that the improved adaptive VMD-MPE algorithm enables automatic determination of modal number K and penalty factorαwhile effectively eliminating noise from the vibration signal,reducing subjective decision-making influence.During posterior excavation tunnel face blasting,interlaid rock exhibits significant amplification effects on blast vibrations.Peak particle velocity(PPV)values are higher in interlaid rock compared to non-interlaid areas.However,vibrations attenuate faster within interlaid rock regions.Additionally,analysis reveals that low-frequency vibrations below 40 Hz account for a substantial proportion of energy within interlaid rock areas when comparing frequency characteristics at measuring points between non-interlaid and interlaid regions.Attention should be given to these low-frequency vibrations as they are more likely to induce resonance in supporting structures,posing higher risks of damage or destruction within interlaid rock zones.By analyzing the blasting vibration characteristics of the cut hole and the surrounding hole,it can be found that the vibration velocity generated by the surrounding hole blasting in the surrounding rock behind the tunnel face is greater than that of the cut hole blasting within the range of the scale distance(SD)which is less than or equal to 11.57 m kg^(1

关 键 词：中夹岩 小净距隧道 爆破振动效应 变分模态分解 多尺度排列熵 

分 类 号：U455.6[建筑科学—桥梁与隧道工程]