Industrial Ring Road Bridges, Bangkok
Mott MacDonald was the joint consultant for the feasibility
study, preliminary design and detailed design of a £128 million
road crossing of Bangkok's Chao Phraya River, which connects the
industrial area south of Bangkok with the Port. The location is 3km
downstream from the existing Rama IX Bridge where a looping meander
of the river leaves a neck of land 600m wide.
Two cable stayed bridges, with main spans of 398m and 326m,
connected by a high level viaduct carry dual three lane
carriageways with an additional climbing lane on the
approaches.
The concrete pylons are of diamond configuration.
Two planes of stay cables support the outer edges of the main span
decks and are designed in steel composite construction.
The prestressed concrete back spans are supported from the ground
and provide the necessary reaction to the stay forces under the
most unfavourable live load combination.
Between the two bridges an elevated central interchange connects
the main North-South route with the western approach. The three
approaches are designed as continuous concrete box girders with
spans varying between 64m for the high level viaducts to 36m for
the lower level viaducts.
