JEDDAH, 1 January 20004 — One of the bridges on the main artery linking Madinah and Makkah may be showing signs of weakness. Jeddah Municipality is, sources say, planning another exit close by to divert traffic round the bridge, Al-Madinah newspaper reported.
The bridge near Briman, approximately 4 km north of the Tahlia Street intersection, is located at a point where the water table is very close to the surface. Brackish water that can attack and decay concrete has surrounded the supporting pillars and soaked the foundations for many months.
Apart from the thousands of cars that cross the bridge each day, a major contributor to damage is the vibration caused by heavy trucks: 16,000 journeys alone by sewage trucks and thousands more by heavy freight vehicles. About 3.5 billion liters of sewage crosses the bridge every month.
Last year, the municipality drained and filled a stagnant pool — which had small fish breeding in it — under the bridge. The work to the ground surface did not cure the underlying cause of the rising water table.
The rocky track under the bridge is a favorite short-cut for motorists seeking to cross the expressway and eliminate a long detour. After the November rains, the water table rose dramatically and combined with run-off, it left a pool over a meter deep for more than a month.
The water table under Jeddah is already causing problems. Foundations of new buildings in Waly Al-Ahad Street fill with water and have to be pumped dry.
Last year, a building collapsed in Balad killing four. Later inspection revealed water at surface level at the site.
One estimate from a source at the Saudi Geological Survey reported at a water conference held in the city last year that the water table under some 70 percent of Jeddah was close enough to the surface to affect building structures.
