1. Design the longitudinal girder of T-beam and slab bridge for the following data:

Effective span 18 m

Carriageway width 7·5m

Kerbs 600 mm on either side

Provide 3 longitudinal beams and 5 cross beam loading

Consider IRC Class AA tracked vehicle loading

Use M 20 and Fe 415 bars.

Use Courbon's method for calculation of reaction coefficients.

Explain the purpose of providing expansion joints in bridges. Explain the various types of expansion joints.

What is the function of bearings in bridges?

Define balanced cantilever bridge. Also give the advantage of balanced cantilever design over simply supported girder design.

Determine the waterway for a bridge across a stream with a flood discharge of 225 velocity 1·5 m/s and width of flow at high flood level 60 if the allowable velocity under the bridge is 1·8 m/s.

Explain briefly the principles of design of the following elements of a prestressed concrete bridge

Mid-span section of girder

End block of girder

Deck slab in 'gap slab' type of deck

What is meant by 'economical span' of a bridge Distinguish between vertical clearance and free board.

Explain with sketches the component parts and structural action of truss bridge, cable stayed bridges and suspension bridge.

What are the characteristics of an ideal site for a major bridge across a river?

6. Design a post-tensioned concrete slab bridge deck for a national highway crossing to suit the following data

Clear span 5·5 m

Width of bearing =400 mm

Clear width of roadway =7·5 m

Footpath on either side m

Kerbs =600 mm wide

Thickness of wearing coat 80 mm.

Consider LL IRC class AA tracked vehicle, Type of structure Class I type, Use M 20 and 7mm cj) wire with ultimate strength=1500N/mm^2, Loss ratio =0·8.

7. Write short notes on any two of the following:

Box culvert

IRC loading standards for highway bridges

Calculation of impact factor for highway bridges.