The first steps towards the restoration and seismic strengthening of the historic cable-stayed suspension bridge of Deir ez-Zor in Syria

Abstract

Introduction. The historic cable-stayed suspension bridge of the city of Deir ez-Zor in Syria, which is an architectural monument, is described. The history of its creation at the beginning of the twentieth century and its destruction during the hostilities in 2013 is given. The importance of this bridge for the city and for the country as a whole is indicated, which was the reason for its choice as an object of research.Aim. The study is intended to contribute to the restoration and (or) subsequent seismic strengthening of the cable-stayed suspension bridge of Deir ez-Zor.Materials and methods. A detailed description and characteristics of the above-mentioned bridge, built according to the system of the French design engineer Albert Gisclard, according to the project of the design engineer Gaston Leinekugel Le Cocq and the construction company “Arnodin”, are given. Suspension and cable-stayed bridges are compared and distinctive features of Gisclard bridges are listed. Radial cablestayed trusses are described and the scheme of load distribution in suspension and cable-stayed bridges is illustrated. Examples of the calculation of the stay cables and their cross-sectional area are briefly given, which can be used in the restoration of the bridge and its cable stays. The method of protecting the bridge from wind and seismic influences is considered.Results. Lines of influence for radial cable trusses of the Gisclard system are illustrated, showing tension and compression zones in the cable stays. Stiffening cables are recommended for adding to the design of multi-span cable-stayed and suspension bridges, as they increase their rigidity. To protect the cable-stayed suspension bridge of the city of Deir ez-Zor from wind and seismic vibration, a method of damping or reducing wind and seismic vibration using magnetorheological liquid dampers with tuned mass is proposed.Conclusions. Conclusions are drawn about the feasibility of seismic strengthening of the Deir ez-Zor bridge together or after restoration with the help of the above-mentioned dampers, which allow protecting the bridge, while maintaining its authenticity and original exterior appearance.