Site Characterization Using Passive Seismic Measurements atDhaka University, Bangladesh
DOI:
https://doi.org/10.64862/Keywords:
Microtremor, Predominant frequency, Dhaka UniversityAbstract
Dhaka is one of the most densely populated cities of the world with rapid urban expansion. The city is mostly covered by soft sediments of Holocene and Pleistocene origin. The depressed areas are filled up by artificial fill to meet the growing demand of land in the capital city. In the GICU project, the Geological Survey of Bangladesh has started to unveil the fundamental frequency with technical support of BGR and instrumental support from the Disaster Science and Climate Resilience department of Dhaka University. We determined resonance frequency from seven ambient noise measurements (recording duration 30-40 minutes) inside and near the Dhaka University campus in the southern periphery of the city using OYO McSEIS-NT NEO seismographs (200 Hz to 10 s frequency response). The survey was done over Pleistocene and Holocene sediments, mostly composed of unconsolidated clayey silt and silty sand. The most reliable “output” from microtremor horizontal-to-vertical spectra ratios is the lowest frequency peak which is interpreted as the site fundamental frequency (f0). The results show variations of natural frequency between 0.85 and 1 Hz with an amplitude of the H/V ratio of 2.4 to 3.
References
Ansary, M. A., and Arefin, M. R. (2020). Assessment of predominant frequencies in Dhaka city, Bangladesh using ambient vibration. Asian Journal of Civil Engineering, 21 (1), 91–104. https://doi.org/10.1007/s42107-019-00194-2
Bonnefoy-Claudet, S., Cotton, F., and Bard, P. (2006). The nature of noise wavefield and its applications for site effects studies: A literature review. Earth-Science Reviews, 79 (3–4), 205–227. https://doi.org/10.1016/j.earscirev.2006.07.004
Farazi, A. H., Hossain, M. S., Ito, Y., Piña-Flores, J., Kamal, A. M., and Rahman, M. Z. (2023). Shear wave velocity estimation in the Bengal Basin, Bangladesh by HVSR analysis: Implications for engineering bedrock depth. Journal of Applied Geophysics, 211, 104967. https://doi.org/10.1016/j.jappgeo.2023.104967
Helaly, A. L., and Ansary, M. A. (2021). Assessment of seismic vulnerability index of RAJUK area in Bangladesh using microtremor observations. Soils and Rocks, 44 (2), e2021057420. https://doi.org/10.28927/SR.2021.057420
Landes, M., Hubans, F., Shapiro, N. M., Paul, A., and Campillo, M. (2010). Origin of deep ocean microseisms by using teleseismic body waves. Journal of Geophysical Research, 115, B05302.
Rahman, M. Z., Hossain, M. S., Kamal, A. S. M. M., Siddiqua, S., Mustahid, F., and Farazi, A. H. (2018). Seismic site characterization for Moulvibazar town, Bangladesh. Bulletin of Engineering Geology and the Environment, 77, 1451–1471. https://doi.org/10.1007/s10064-017-1031-6
Rahman, M. Z., Siddiqua, S., and Kamal, A. S. M. M. (2021). Site response analysis for deep and soft sedimentary deposits of Dhaka City, Bangladesh. Natural Hazards, 106, 2279–2305. https://doi.org/10.1007/s11069-021-04543-w
Singh, A., Bhushan, K., Singh, C., Steckler, M. S., Akhter, S. H., Seeber, L., and Biswas, R. (2016). Crustal structure and tectonics of Bangladesh: New constraints from inversion of receiver functions. Tectonophysics, 680, 99–112. https://doi.org/10.1016/j.tecto.2016.04.046
Downloads
Published
Issue
Section
License
Copyright (c) 2025 Nepal Society of Engineering Geology (NSEG)
This work is licensed under a Creative Commons Attribution 4.0 International License.
