论文部分内容阅读
为了控制隧道爆破振动对临近建筑物的影响,依托大连南部滨海大道隧道工程,进行了自然环境地脉动和隧道爆破振动激励下的典型5层砖混建筑物的运行模态分析(OMA)试验,对比分析了这2种不同激励的特点,采用随机子空间法识别了建筑物的固有频率、阻尼和振型;研究了爆破作用下建筑物不同楼层的振动反应;在建筑物模态分析基础上,进行了毫秒非电雷管和电子雷管的隧道爆破减振试验,并对比分析了采用2种雷管的不同爆破设计引发的爆破地震波的特点。结果表明:自然环境地脉动可以对楼房的低阶模态进行有效激励,获得建筑物的低阶固有频率和1阶、2阶弯曲振型,但对于高阶模态识别较为困难;隧道爆破振动能够同时激励出建筑物的低阶模态和部分高阶模态,由此获得了5层砖混建筑物的1~8阶固有频率为4.16~42.99Hz;高频爆破地震波沿楼层向上传播过程中不断衰减,地震波以低频为主,导致位于隧道爆破掌子面上方的建筑物测点的振速随楼层的增高先减小,再增大,而后又减小;采用毫秒非电雷管和电子雷管起爆均可以控制爆破地震波的主频,使其远离建筑物的低阶整体固有频率,从而减小因共振造成的结构损伤,但是相比非电雷管,采用电子雷管单孔药量间隔起爆更能有效降低峰值振速。
In order to control the impact of tunnel blasting vibration on the adjacent buildings, an operational mode analysis (OMA) test of a typical 5-storey brick-concrete building under natural pulsation and tunnel blasting vibration was carried out based on the Dalian Binhai Avenue tunnel project. The characteristics of these two kinds of excitation are compared and analyzed. The random subspace method is used to identify the natural frequency, damping and mode shapes of buildings. The vibration responses of different floors of buildings under blasting are studied. Based on the modal analysis of buildings, , The tunnel blasting vibration test of millisecond non-electric detonator and electronic detonator was carried out, and the characteristics of blasting seismic waves triggered by different blasting designs with two types of detonators were contrasted and analyzed. The results show that the pulsation of the natural environment can effectively stimulate the low-order mode of the building to obtain the low-order natural frequencies and the first and second order flexural modes, but it is difficult for the high-order mode identification. The tunnel blasting vibration can be simultaneously The low-order modes and some high-order modes of buildings are stimulated, and the natural frequencies of 1st to 8th floors of 5-story masonry buildings are 4.16-42.99Hz. The high-frequency blasting seismic waves continue to decay along the floor upward, The seismic wave is dominated by low frequency, which leads to the vibration speed of the building measuring point located above the face of the tunnel blasting decreasing first, then increasing, and then decreasing again. The millisecond non-electric detonator and electronic detonator can both detonate The dominant frequency of blasting seismic wave is controlled away from the low-order natural frequency of building so as to reduce the structural damage caused by resonance. However, compared with non-electric detonator, the use of electron detonator single-hole dose interval detonation can effectively reduce the peak value Vibration speed.