Al-Muhandis was a principal member and sole Saudi partner of the consulting group (Saudi Danish Consultants) which completed the study, design, and construction supervision during the period 1975-1986, of the famous causeway linking Saudi Arabia with Bahrain. The project was proceeded by a feasibility study for selecting alternative area routes, alternative start and finish landing points, optimum construction materials, and the effect of each alternate route on navigation and the marine environment.
Saudi-Bahrain Causeway compromised a sea crossing of 25km length total, of which 12.5km are causeway and 12.5km of low level bridge having 50m span. Only the main navigation span, which was 150m in length had 28m free height. It was designed as free cantilever with segmental construction. Pile foundation posed a delicate risk. There was a stringent requirement to avoid puncturing sweet water aquifers, underlying sea bottom, extending between Saudi Arabia and Bahrain. Total construction cost amounted to 800 million USD.
