深埋隧洞钻爆开挖围岩振动频率特性研究

发布时间：2019-04-28 18:55

【摘要】：针对深埋圆形隧洞全断面毫秒延迟钻爆开挖,通过建立开挖面上地应力瞬态卸荷与爆炸荷载激发围岩振动的理论计算模型,并结合实测振动信号分析,研究了影响围岩振动频率的因素及其频谱特性。研究结果表明,瞬态卸荷持续时间、爆炸荷载上升时间和开挖面大小是影响深埋隧洞钻爆开挖围岩振动频率的主要因素;在爆源近区围岩振动以爆炸荷载作用为主,但爆炸荷载上升时间远小于瞬态卸荷持续时间,由此导致爆炸荷载激发振动的频率高,其质点峰值振动速度衰减快,在中远区地应力瞬态卸荷可成为引起围岩振动的主要因素;瞬态卸荷与爆炸荷载共同作用产生的振动具有两个优势频带,其低频成分主要由瞬态卸荷引起,而高频成分主要由爆炸荷载引起。
[Abstract]:In view of the millisecond delayed drilling and blasting excavation of the whole section of the deep-buried circular tunnel, the theoretical calculation model of the in-situ stress transient unloading on the excavation surface and the vibration of the surrounding rock excited by the explosive load is established, and combined with the analysis of the measured vibration signals, The factors affecting the vibration frequency of surrounding rock and its spectrum characteristics are studied. The results show that the transient unloading duration, the rising time of explosive load and the size of excavation surface are the main factors affecting the vibration frequency of surrounding rock in deep-seated tunnel drilling and blasting excavation. The vibration of surrounding rock near explosive source is dominated by explosive load, but the rising time of explosive load is much shorter than the duration of transient unloading, which leads to the high frequency of vibration excited by explosive load and the fast attenuation of peak vibration velocity of particle. The transient unloading of in-situ stress in the middle-far region can be the main factor causing the vibration of surrounding rock. The vibration produced by the interaction of transient unloading and explosive load has two dominant bands, the low frequency component is mainly caused by transient unloading, and the high frequency component is mainly caused by explosive load.
【作者单位】：南昌大学建筑工程学院;武汉大学水资源与水电工程科学国家重点实验室;
【基金】：国家自然科学基金资助项目(No.51509126,No.51409138) 江西省自然科学基金资助项目(No.20161BAB206127)~~
【分类号】：TU45

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