7. FUNCTIONS OF THE FOUNDATIONS
➢To provide stability to the bridge on the whole.
➢To provide a leveled base for the construction of pier and abutments.
➢To prevent the tilt and over turning of the pier and Abutments.
➢To prevent unequal settlement of subsoil.
➢The load transferring uniformly over the subsoil.
➢The foundation are carry the super structure load.
17. COFFERDAM
A cofferdam is a temporary enclosure built within, or
in pairs across, a body of water and construction to allow
the enclosed area to be pumped out, creating a dry work
environment for the major work to proceed.
18.
19. USES
➢ Pile driving operation.
➢ Construct new structures.
➢ Enclose space for removal.
➢ Place grillage & raft foundation.
➢ Constructing without disturbances.
20. REQUIREMENTS OF A COFFERDAM
➢ It should be reasonably water-tight.
➢ It should be easy to construction at the site of work.
➢ It should provide least obstruction to the flow of
river water.
➢ Its cost of construction and maintenance should be
low.
21. TYPES OF COFFERDAM
❖ Earth fill Cofferdam
❖ Rock fill Cofferdam
❖ Rock fill crib Cofferdam
❖ Single wall Cofferdam
❖ Double wall Cofferdam
❖ Cellular Cofferdam
❖ Concrete Cofferdam
❖ Suspended Cofferdam
