Civil Engineering and Architecture Vol. 13(1), pp. 224 - 236
DOI: 10.13189/cea.2025.130113
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The H/V Spectral Ratio Technique for Dynamic Characterization of Existing Buildings in Morocco

Nchiti El Mehdi ^1,2,*, El Hammoumi Abdellah ², Iben Brahim Aomar ³, Cherraj Mohammed ², El Hachmi Driss ², Jouhar Abderrahmane ^2
1 Laboratory of Advanced Materials Studies and Applications (LEM2A), Higher School of Technology, Moulay Ismail University, Morocco
² MSME, Faculty of Sciences, Mohammed V University, Morocco
³ Department of Globe Physics, Scientific Institute, Mohammed V University, Morocco

ABSTRACT

On September 8, 2023, Morocco suffered a severe earthquake in the Al-Houaz region, with a magnitude of 6.8 on the Richter scale. Some areas were more severely affected than others, with different degrees of damage observed on buildings of the same type. It appears that site effects, aging, and structural degradation are responsible for the increase in this damage. To understand these effects, the H/V spectral method provides useful information on the dynamic behavior of buildings using microtremor measurements. In this study, the frequencies and damping of a set of Moroccan buildings are derived from measurements of ambient vibrations and compared to those given by the Moroccan seismic code and research works. For this purpose, ambient vibration measurement is performed on 17 existing buildings, representing the seismic classification of the European Macroseismic Scale. This study shows that damping on different buildings is frequency-dependent, which can be explained by the effect of radiative damping when buildings are founded on flexible soils and is a possibility to take into account in seismic design. A comparison of the frequencies measured at the top with those on the soil indicates the risk of soil-structure resonance. Also, the variation in frequency between the regulatory state and the ambient vibrations shows a decrease in frequencies for all buildings of vulnerability classes A and B, while for buildings of classes C and D, no variation in frequency was observed. This highlights a qualitative assessment of the damage and loss of rigidity of the buildings measured.

KEYWORDS
H/V Method, Ambient Vibrations, Nakamura Method, Soil-Structure Resonance, Seismic Vulnerability

Cite This Paper in IEEE or APA Citation Styles
(a). IEEE Format:
[1] Nchiti El Mehdi , El Hammoumi Abdellah , Iben Brahim Aomar , Cherraj Mohammed , El Hachmi Driss , Jouhar Abderrahmane , "The H/V Spectral Ratio Technique for Dynamic Characterization of Existing Buildings in Morocco," Civil Engineering and Architecture, Vol. 13, No. 1, pp. 224 - 236, 2025. DOI: 10.13189/cea.2025.130113.

(b). APA Format:
Nchiti El Mehdi , El Hammoumi Abdellah , Iben Brahim Aomar , Cherraj Mohammed , El Hachmi Driss , Jouhar Abderrahmane (2025). The H/V Spectral Ratio Technique for Dynamic Characterization of Existing Buildings in Morocco. Civil Engineering and Architecture, 13(1), 224 - 236. DOI: 10.13189/cea.2025.130113.