The road bridge across Rangit river in Jorethang in the state of Sikkim replaces an old suspension bridge. The aim in the project was to adapt the relatively advanced concept of the cable-stayed bridge to the special conditions of a third world country - with the added problem of a remote and mountainous location.
To avoid the importance of large quantities of high quality steel, the deck and pylons were designed entirely in reinforced concrete: the first cable-stayed bridge of this type in Asia.
The bridge deck is not connected with the pylon, but entirely suspended. The cable could be manufactured in Sikkim: it consists of a simple bundle of parallel wires kept in shape by a long lay twist, so that the conventional sheath can be dispensed with. To protect the wires from corrosion, the cables are filled and painted with polyurethane. Connections at the end are formed by pouring molten zinc into the sockets to fully bond the cables.
State of Sikkim
Gammon India Ltd., Bombay
- Our Scope of Work
construction design, site supervision