Week 4 Challenge

Aim and intriduction -

Foundation is the component of bridge which accepts the external or internal forces / loads coming through substructure and superstructure and spreads the forces / loads uniformly to the earth. It also guarantees stability of whole structure as well as self protection from scour. So bridge designer’s prime aim is to design and construct an economical and stable foundation for 100 and more than 100 years.

Step 1 Collecting design data.

a Carriageway detail,

b Span,

c Superstructure details

d Material Grade

e Geo-technical data

Step 2 Assumptios

a Heel Slab Thickness,

b Toe Slab Thickness,

c Footing dimensions

Step 3 Load calculations

Step 4 Load combinatios

a Base pressure check (If satisfied OK, If not revise the section)

b Staibility check

b1 Overturning stability (If satisfied OK, If not revise the section)

b2 Sliding stability (If satisfied OK, If not revise the section)

Step 5 Design of foundation

a Ultimate Limit State

a1 Flecure capacity (If satisfied OK, If not revise the section)

a2 Shear check (If satisfied OK, If not revise the section)

b Serviceability Limit State

b1 Stress check for Allowable stress (If satisfied OK, If not revise the section)

b2 Crack width check for Allowable crack width.(If satisfied OK, If not revise the section)

Step 6 Drawing and reinforcement detailing.

If satisfied OK,

If not revise the section

Design of abutmen foundation as follows

a

A bridge in river has to face loads of water current in addition to other loads comes on flyover. Scour level governs the depth of foundation in addition to other parameters for depth in flyover.