TY  - EJOU
AU  - Xie, Zhangdi 
AU  - Zhuang, Cantao 
AU  - Wu, Yong 
AU  - Niu, Linghui 
AU  - Zhao, Jianming 

TI  - H/V Spectral Ratio Reveals Seismic Response of Base-Isolated Large-Span High-Rise in Beijing
T2  - Structural Durability \& Health Monitoring

PY  - 2026
VL  - 20
IS  - 1
SN  - 1930-2991

AB  - This study employed tri-component continuous monitoring data from 10 measurement points on both sides of a base isolation layer in the basement of a large-span high-rise building in Beijing, as well as from a free-field station and roof frame, during a <i>M</i><sub>w</sub> 5.5 magnitude earthquake in Pingyuan, Shandong, in 2023. The H/V spectral ratio method was used to evaluate the structural dynamic response characteristics of the building and analyze the regulatory effect of the base-isolation layer on seismic waves. The results indicate that during the earthquake, the peak frequency of the free-field and the measurement points below the base-isolation layer was stable at 0.17 Hz, whereas the main frequency of the measurement points above the base-isolation layer increased to 0.75–1.18 Hz, which is 4–6 times greater than that of the points below. The amplitude was suppressed by more than 70%, confirming that the base isolation layer effectively isolated the low-frequency energy from the ground and increased the response frequency of the building. When the building was excited by an earthquake, a three-tier frequency gradient was formed throughout the building: “base-isolation layer (0.17 Hz)-main body (1.18 Hz)-roof frame (3.83 Hz)”, which can effectively avoid resonance of the entire building. In addition, the composite base-isolation device changed the dynamic characteristics of the structure. The resonance period was extended from 0.74 s (theoretical value without base isolation) to 5.9 s (calculated value), and the resonance frequency was reduced from 1.35 to 0.17 Hz. This finding indicates that the base-isolation layer can enhance seismic performance by increasing flexibility and damping.
KW  - H/V spectral ratio method; seismic isolation system; seismic response characteristics; three-stage frequency gradient; energy dissipation mechanism

DO  - 10.32604/sdhm.2025.070531