MEMS地震烈度仪在结构地震反应观测中的应用

Application of MEMS seismic intensity instrument in structural seismic response observation

工程结构地震反应观测台阵获取常时和震时结构反应记录,是工程结构健康诊断和震害评估的重要技术手段之一。2019年,云南大理建设了一个由8个地震烈度仪测点组成的结构地震反应观测台阵,每台烈度仪内置一个3分向微电子机械系统(Micro-Electro-Mechanical System,MEMS)加速度计。通过标准振动台检测,确定台阵配备的烈度仪的幅频响应特性曲线和线性度误差符合相关行业标准的要求。该台阵于2021年5月获得了大理漾濞地震序列的多次结构地震反应记录,本文选取其中3次M_(S)3.0~M_(S)3.2级地震,分析了观测记录的加速度时程、傅里叶幅值谱和信噪比等数据,由结果可知:该台阵可较好地记录幅值≥0.5 cm/s^(2)、频带1.0~39.0Hz的振动信号,对于近场小震具有一定的监测能力。

The seismic response observation array of engineering structures,obtaining the structural response records at regular time and during the earthquake,is one of the important technical means for the health diagnosis and earthquake damage assessment of engineering structures.In 2019,a structural seismic response observation array was built in Dali,Yunnan,consisting of 8 seismic intensity instruments measuring points,with 3 components built-in Micro-Electro-Mechanical System(MEMS)accelerometers.The detection of intensity meter based on standard shaking table test shows that the frequency amplitude response curve and the linearity error were qualified.The array obtained multiple structural seismic response records in the Dali Yangbi earthquake sequence in May 2021.In this paper,for the three earthquakes with a magnitude of M_(S)3.0-M_(S)3.2,the acceleration time histories,Fourier amplitude spectra and signal-to-noise ratios of the observation records were analyzed.According to the analysis results,the array can be used to record the vibration signals of small earthquakes in near field with amplitude above 0.5 cm/s^(2) and frequency band 1.0-39.0 Hz.