The Great Gulf of Aqaba 1995 Earthquake Design Response Spectra over Sinai Peninsula and Some Jordanian Soils

Abstract

The Gulf of Aqaba area is considered one of the most terrific touristic areas in the Middle East. The aim of the present work is to determine the amount of seismic hazards that the constructions may suffer due to seismic activities. This is done by determining the design response spectrum for this area from available earthquake response spectra, then taking into consideration the soil response for some Egyptian and Jordanian soils. The main shock of the November 22, 1995, the Gulf of Aqaba and its aftershocks were mainly used in producing the design response spectrum. This earthquake was considered as the biggest earthquake that hit this area since 160 years. Its magnitude was determined as Mw = 7.2. Thousands of aftershocks with intermediate magnitude followed the main shock, such as the aftershock that occurred on November 23, 1995 with a local magnitude of M L = 5.4. The best estimate of the focus location was determined in the area between Dahab and Nuweiba cities. This great earthquake was felt in Lebanon, Syria and Israel in the North and Egypt, Saudi Arabia and Sudan in the South. The touristic areas surrounding the Gulf of Aqaba were mostly affected. Different accelerograms for this great earthquake were collected and soil responses spectra for Sinai Peninsula and some Jordanian soils were calculated. The design response spectrum shows an average spectral acceleration of about 250 cm/sec 2 for frequency range between 1 - 10 HZ. Soil Amplifications were then calculated using Microtremors site response technique and maximum spectral accelerations filtered by the soil were in range between 120 - 450 cm/sec 2 for the study area. The analysis presented here is intended to be used in the future to allow reducing the seismic risk, help in proper structural design and detailing of buildings and structures to account for beam-column connections and shear reinforcement.