ESTIMATING STRUCTURAL DISPLACEMENT FROM EARTHQUAKE-INDUCED ACCELERATION USING SINGULAR SPECTRUM ANALYSIS

使用奇異譜分析從地震引起的加速度估計結構位移

Shieh-Kung Huang(黃謝恭) ； Chin-Hsiung Loh(羅俊雄)

《中國土木水利工程學刊》 34卷7期 (2022/11) Pp. 619-629

https://doi.org/10.6652/JoCICHE.202211_34(7).0006

摘要

Inter-story drift or roof drift plays an important role in the seismic damage assessment of building structures once structural displacement can be properly measured or estimated. For structural health monitoring (SHM), considering their cost, accelerometers are generally used to measure the responses instead of using displacement meters. Many researchers proposed different schemes to correct the baseline drifts in the recorded acceleration and try to avoid the trends in the integrals of velocity and displacement. Nevertheless, few of them can have great performance on the structural responses. This study proposes a combination of singular spectrum analysis (SSA) and integration scheme to estimate the structural displacement directly from the recorded acceleration. Moreover, the proposed scheme is verified using the shaking table test. SSA decomposes the acceleration measurement into approximation and detail parts; the approximation parts are used as weighting factors, and the detail parts are integrated twice to have the temporary displacement. Both the relative displacement and the induced permanent deformation during earthquake excitations are correctly estimated.

關鍵字

residual deformation ； displacement estimation ； inter-story drift ； singular spectrum analysis ； damage assessment

並列摘要

在建築結構的災後損傷評估中，層間變位（inter-story drift）或是頂層變位（roof drift）扮演極其重要的角色，只要能夠正確測量或估計結構位移，工程師可以輕易的利用這些資訊判斷結構物的大致狀態。對於結構健康監測（structural health monitoring，SHM）來說，因為成本的原因常使用加速度計來測量結構反應而非位移計，過去許多學者嘗試利用不同的方法來校正加速度中的基線漂移（baseline drifts），但均難能在結構反應上呈現較好的應用成效。鑑此，本研究提出結合奇異譜分析（singular spectrum analysis）與數值積分的組合方案，並且利用振動台試驗驗證此法的可行性，奇異譜分析將加速度測量分解為近似部分和細節部分；將近似部分作為權重因子，對細節部分進行二次積分，產生臨時位移，最終可以正確的估計地震下結構物的相對位移和結構的永久位移。

並列關鍵字

殘於位移 ； 位移估計 ； 層間位移 ； 奇異譜分析 ； 損傷評估

參考文獻

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Housner, G. W., “Ground displacement computed from strong-motion accelerograms,” Bulletin of the Seismological Society of America, Vol. 37, No. 4, pp. 299- 305 (1947).

Berg, G. V. and Housner, G. W., “Integrated velocity and displacement of strong earthquake ground motion,” Bulletin of the Seismological Society of America, Vol. 51, No. 2, pp. 175-189 (1961).

Skolnik, D. A. and Wallace, J. W., “Critical assessment of interstory drift measurements,” Journal of Structural Engineering, Vol. 136, No. 12, pp. 1574-1584 (2010).

Liao, Y., Kiremidjian, A., Rajagopal, R., and Loh, C. H., “Experimental validation of an improved dynamic displacement estimation method using accelerometer and gyroscope,” Structural Health Monitoring (2017).