Liquefaction potential of Nile delta, Egypt

Abstract

Understanding how sedimentary basins respond to seismic-wave energy generated by earthquake events is a significant concern for seismic-hazard estimation and risk analysis. The main goal of this study is assessing the vulnerability index, K g , as an indicator for liquefaction potential sites in the Nile delta basin based on the microtremor measurements. Horizontal to Vertical spectral ratio analyses (HVSR) of ambient noise data, which was conducted in 2006 at 120 sites covering the Nile delta from south to north were reprocessed using Geopsy software. HVSR factors of amplification, A, and fundamental frequency, F, were calculated and K g was estimated for each measurement. The K g value varies widely from south toward north delta and the potential liquefaction places were estimated. The higher vulnerability indices are associated with sites located in southern part of the Nile delta and close to the branches of Nile River. The HVSR factors were correlated with geologic setting of the Nile delta and show good correlations with the sediment thickness and subsurface stratigraphic boundaries. However, we note that sites located in areas that have greatest percentage of sand also yielded relatively high K g values with respect to sites in areas where clay is abundant. We concluded that any earthquake with ground acceleration more than 50 gal at hard rock can cause a perceived deformation of sandy sediments and liquefaction can take place in the weak zones of K g ! 20. The worst potential liquefaction zones (K g > 30) are frequently joined to the Damietta and Rosetta Nile River branches and south Delta where relatively coarser sand exists. The HVSR technique is a very sensitive tool for lithological stratigraphy variations in two dimensions and varying liquefaction susceptibility.

Estimation of seismic site effect at the new Tiba City proposed extension, Luxor, Egypt

“…The application of this technique (i.e. determination of K g from microtremor HVSR) has been recently applied in Egypt by Fergany and Omar (2017) and Meneisy et al (2020) with reasonable results.…”

Local Site Effects Evaluation for Gyobyu Lifeline using Microtremor Measurements

“…Kg index was estimated for each site based on Nakamura (1996,1997,2000) technique. [10] A. Procedure for analysis This is the general procedure for calculation of H/V spectral ratio from record observation.…”

“…Kg value reflect local site effect and can be considered as an indicator which might be useful in selecting weak point of ground especially along pipeline areas. International Journal of Trend in Scientific Research and Development (IJTSRD) ISSN: 2456 www.ijtsrd.com | Volume -3 | Issue -1 | Nov-Dec fundamental frequency (F) for each observation point.index was estimated for each site based on ) technique [10]. neral procedure for calculation of H/V Procedure of H/V spectral ratio…”

Assessing the liquefaction potential of seabed soils based on ocean ambient noise in the Yellow River Delta

“…At present, there are three primary methods for assessing soil liquefaction: in-situ tests (Fergany and Omar, 2017), laboratory tests (Kumar et al, 2020), and numerical simulation (Ye et al, 2016;Zhao et al, 2018). These methods have been maturely applied in the study of liquefaction in sandy soils due to their safety and reliability (Amini and Qi, 2000;Dobry and Abdoun, 2017;Ye et al, 2018).…”