Study of dynamic response of High-Rise buildings under blasting earthquake considering model simplifying

Abstract

Based on the blasting engineering of the subway tunnel, the overall dynamic response of the 28-story frame-shear-wall structure is studied by field test and numerical analysis. Field test is the blasting vibration monitoring and operational mode analysis (OMA). OMA used Ibrahim Time Domain method to extract the modal frequencies, the modal damping ratio of the structure, provided the basis for further analysis of the vibration response laws. The structure is simplified into a mass-spring-damper model. Based on the modal parameters extracted from the AVT, fixed the stiffness matrix and the damping matrix of the mass-spring-damper model, and set up the dynamic differential equation. So the modal parameters and frequency-response-functions of the building bending vibration can be calculated. SIMULINK dynamic simulation model was established based on the dynamic differential equation of the mass-spring-damper model. Based on the blasting vibration velocity signal, the overall vibration response law of high-rise buildings under tunnel blasting seismic is analyzed. The following conclusions are drawn: 1. Under the blasting vibration of the subway tunnel, the vibration response velocity of high-rise buildings presents: vertical vibration is the largest, lengthways vibration velocity is the second, and transverse vibration velocity is the smallest. However, the vertical vibration velocity peak and tangential vibration velocity peak at the higher floors is not much different. 2. On the higher floors, the velocity peaks fluctuated with floor increasing, and fluctuation is interrelated with the dominant mode. The peak value of vibration velocities distribution shows this correlation; 3, To simplify the high-rise building to be the mass-spring-damper model and set up the mathematical model of dynamic reaction. Then, the Simulink simulation model was established for simulation calculation. This method can adequately predict the response of the structure under blasting vibration.

Keywords:

• Dynamic response
• dynamic characteristics
• modal analysis
• high-rise buildings
• blasting earthquake
• model simplifying

Disclosure statement

No potential conflict of interest was reported by the authors.