Geotechnical and geophysical investigation techniques in Ben Ezra Synagogue in Old Cairo area, Egypt

Sayed Hemeda

doi:10.1186/s40494-019-0265-y

Abstract

The Ben Ezra Synagogue or El-Geniza Synagogue or the Synagogue of the Levantines, is located in the Coptic section of Old Cairo area. It is considered the oldest Synagogue or Jewish temple found in Egypt represents cultural heritage of outstanding universal values. It suffers multiple environmental, geotechnical and earthquake hazards. The integrated geotechnical and geophysical investigation techniques were done to assess the level of seismic and other geo-environmental hazards and risk that Synagogue suffers from in present and future. This knowledge is required to protect the building against seismic events. The Synagogue suffers high risk in terms of seismic and environmental hazards. The main purposes of the present study are to: (1) Assess the level of seismic and other geo-environmental hazards at Ben Ezra Synagogue. (2) Understand the damage situation for the historic building caused by the recent earthquakes. (3) Offer technical support and advice on restoration and repairs for the damaged structure. (4) Build up knowledge and case studies towards the restoration and repairs, and to survey the damage state of the historic structure. However, Ben Ezra Synagogue is the oldest Jewish temple that was constructed with little or no seismic considerations that represent the largest risk to most communities. These significant historical buildings must be assessed their level of risk determined, and unacceptable risks reduced. This paper focuses on the issues associated with detailed procedures of risk and hazards assessment for retrofitting of architectural heritage. Many forms of evaluation and related procedures for assessment of seismic risk for historical buildings have been discussed. This study, suggest moderate level of earthquake activity at Ben Ezra Synagogue and this is in a good agreement with the fact that “Egypt is a part of the stable African Shield”, but the existence of old structure such as the Ben Ezra Synagogue may reduce the ability to resist any earthquake shaking. This pilot study is important with respect to the continuous efforts for preservation and restoration of the cultural heritage worldwide.

Highlights

Seismic analysis and planning is part of ongoing archaeological site management and conservation [1,2,3]
This study, suggest moderate level of earthquake activity at Ben Ezra Synagogue and this is in a good agreement with the fact that “Egypt is a part of the stable African Shield”, but the existence of old structure such as the Ben Ezra Synagogue may reduce the ability to resist any earthquake shaking
Refraction microtremors test was applied to four tests around the Ben Ezra Synagogue to detect the shear strength in terms of S-wave velocity and detect the average depth of the bedrock

Summary

Introduction

Seismic analysis and planning is part of ongoing archaeological site management and conservation [1,2,3]. In the last few years there has been significant and detectable deterioration to some of the major monuments in old Cairo area, like Ben Ezra Synagogue or El-Geniza Synagogue or the Synagogue of the Levantines [4], calling for an even more intensive and thorough review of their problems and needs, due tone of the most potentially. The selection of appropriate elastic response spectra according to soil categories and seismic intensity is the simplest way to account for site effects both for engineering projects and for a general-purpose microzonation study. Contemporary seismic codes (IBC 2000, UBC97, EC8) have largely accepted the significant role of site effects and attempt to incorporate their influence either by means of a constant amplification factor exclusively dependent on the soil class or including. Soil classification exclusively based in terms of VS, 30 assumption, is a rather simplified hypothesis, misleading in many cases, which can potentially lead to erroneous results, especially in cases of deep soil formations or abrupt stiffness change between the soil layer at − 30 m and the bedrock laying deeper [5,6,7,8,9,10,11]

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Results

Discussion

Conclusion