城市轨道爆破引发邻近建筑振动效应模拟研究

Simulation Study on Vibration Effect of Adjacent Buildings Caused by Urban Rail Blasting

爆破技术凭借经济和高效的特点被应用在城市轨道建设中,但其所产生的振动效应会引起邻近建筑物质点位移、速度和频率等变化,从而产生安全隐患。针对城市轨道爆破过程中引发的邻近建筑物振动效应进行模拟研究。首先对邻近建筑物和城区轨道构建有限元模型,通过气体压力与体积变化的状态方程Jone-Wikin-Lee对炸药进行描述。通过数值模拟的计算结果,了解建筑物因爆破导致的振动效应,依据爆破理论和爆破荷载的经验,求解荷载峰值,通过微分方程的稳态解,结合折算荷载的幅值求出广义坐标向量,进而求解出建筑物在振动过程中的实际振动位移。根据爆破振动波形施加荷载,对质点振动速度进行观察,由微分方程得到质点的振动位移和振动速度曲线。通过回归研究,对爆破点随机监测5次记录,分析了爆破所产生的振动波在邻近建筑物周围的传播规律,结合振动波衰减方程,证明了通过质点的振动速度来控制建筑物的安全性较为合理,上述研究结果对城市轨道建设过程中的爆破施工技术具有一定的参考价值。

Blasting technology is applied in urban rail construction with the characteristics of economy and high efficiency. However, the vibration effect produced by blasting technology will change the displacement, speed and frequency of adjacent building material points, which will cause safety hazards. Therefore, the vibration effect of adjacent buildings caused by urban rail blasting was simulated. Firstly, a finite element model was constructed for the adjacent buildings and urban rail, and the explosive was described by Jon wikin Lee equation of state of gas pressure and volume change. Secondly, through the numerical simulation results, the vibration effect of buildings caused by blasting was understood. According to the blasting theory and experience of blasting load, the peak load was solved. Through the steady-state solution of differential equation and the amplitude of converted load, the generalized coordinate vector was obtained, and then the actual vibration displacement of the building in the process of vibration was solved. Finally, the blasting vibration waveform was selected as the applied load to observe the particle vibration velocity, and the vibration displacement and vibration velocity curve of the particle can be obtained from the differential equation. Through regression study, the blasting points were randomly monitored for five times, and the propagation law of vibration wave generated by blasting around the adjacent buildings was analyzed. Combined with the vibration wave attenuation equation, it is proved that the safety of buildings controlled by the vibration velocity of particles is more reasonable. The research results of this paper have certain reference value for the blasting construction technology in the process of urban rail construction.