临近地铁车站爆破振动效应对高层建筑的影响

Research on the influence of blasting vibration on high-rise building near subway station

  • 摘要: 明晰建(构)筑物的爆破振动响应规律在工程和经济上具有重要意义。针对某地铁车站A出入口爆破施工,运用HHT方法分析某小区2号楼振动信号的衰减特征。研究结果表明:沿高程增加方向,三矢量振速峰值先急剧衰减,后在中间楼层呈波浪形变化并在顶层放大,振速变化分为衰减区(0~26. 15 m、波动区(26.15~71.75 m和放大区(71.75~94.55 m。随高程增加,Hilbert谱的形态由三峰值逐渐转变为单峰值结构,能量幅值降低;优势频带由75~125 Hz衰减为10~40 Hz,主频向低频过渡,振速放大区楼层振动频率较低且易引发共振。根据地面测点拟合顶层能量谱的构成,验证了顶层放大效应的实质,是对爆破地震波中与建筑物固有频率接近的能量进行选择放大。

     

    Abstract: Making clear the vibration response law of buildings(structures)due to blasting is of great significance both engineeringly and the economically. By conducting blasting experiment at subway station entrance A, the vibration signal of building NO.2 was analyzed through Hilbert-Huang transform. Results indicate that as height increases, the three-vector peak vibration velocity attenuate sharply, and then shows a wave-shaped change in the middle and amplify on the top floor, which was divided into attenuation area(0~26.15 m, fluctuation area(26.15~71.75 mand amplification area(71.75~94.55 m. The shape of the Hilbert spectrum gradually changes from three-peak to single-peak, the dominant frequency band attenuates from 75~125 Hz to 10~40 Hz and the energy amplitude decreases. This demonstrates that the lower vibration frequency of the floor in the amplification area could easily cause resonance. Based on the composition of the top-level energy spectrum fitted by the ground measuring points, it is verified that the essence of the top-level amplification effect is to selectively amplify the energy close to the natural frequency of the building in the blasting seismic wave.

     

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