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III Semester M.E. (Civil) (Structural Engg.) Degree Examination, January/February 2014 SE – 302 : ADVANCED DESIGN OF BRIDGES (Common for Structures, PSC and Earthquake Engg.) Time : 3 Hours

Max. Marks : 100

Instructions : i) Answer any four full questions. ii) Assume any missing data suitably. iii) IRC 6, IRC 18, IRC 21, IS 1343, IS 456 and Pigeaud’s charts are allowed. 1. a) Design a slab culvert for the given data :

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i) Clear span : 6 m ii) End bearing : 500 mm iii) Width of road way : 7.5 m iv) Width of kerb : 600 mm v) Thickness of parapet : 150 mm vi) Live load : IRC class AA tracked vehicle. b) Explain the loads considered for the design of bridges.

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2. A T-beam bridge is to be designed for a National Highway for the following data :

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i) Effective Span : 16 m ii) Clear Roadway : 7.5 m iii) Footpath including parapet : 750 mm iv) Live load : IRC class AA Tracked vehicle v) Concrete : M20/Steel : Fe 415 vi) Main girders are placed at 2.5 m c/c. Design the Deck slab and Intermediate main girder. P.T.O.

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3. Design and sketch a RC Box culvert having a clear ventway of 3m × 3m. The super imposed dead load on the culvert is 13 kN/m2. The live load on the culvert is 50 kN/m2. Density of soil at site is 18 kN/m3. Angle of repose = 30°. Adopt M 20 concrete and Fe-415 steel. 25 4. Design a post tensioned prestressed concrete slab bridge deck for a National highway crossing to suit the following data :

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i) Clear span : 10 m ii) Width of bearing : 400 mm iii) Clear width of Roadway : 7.5 m iv) Footpath : 1 m on either side v) Kerbs : 600 mm wide vi) Thickness of wearing coat : 80 mm vii) Live load : IRC class AA tracked vehicle viii) Type of structure : Class 1 Type Materials : M-40 concrete and 7mm diameter high Tensile wires with an ultimate tensile strength of 1500 N/mm2 housed in cables with 12 wires and anchored by Freyssinst anchorages of 150 mm diameter. ix) For supplementary reinforcement, adopt Fe-415 x) Compressive strength at transfer (fci) = 35 N/mm2 xi) Loss Ratio = 0.8 Sketch the longitudinal and cross sections. 5. a) The foundation for substructures of a bridge consists of 16 piles to carry a total load of 8000 kN. The piles are spaced at 1.5 m c/c. They are driven through soft ground to a hard stratum available at a depth of 12 m. Design the pile foundation using M 20 concrete and Fe 415 steel. 10

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b) Verify the adequacy of the dimensions for the pier with the following details :

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i) Top width of the pier : 1.6 m ii) Height of the pier up to springing level : 10 m iii) c/c of bearings on either side : 1.0 m iv) Side butter : 1 in 12 v) High flood level : 1 m below the bearing level vi) Span of the bridge : 16 m vii) Loading on span : IRC class AA traced vehicle viii) Road : Two lane road with 1m width footpath on either side ix) Superstructure : Consists of three longitudinal girders of 1.4 m depth with a deck slab of 200 mm depth rib width of girders : 300 mm x) Concrete : M 20 grade 6. a) Explain with neat sketches types of bearings.

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b) Design a RC rocker bearing to transmit a support reaction of 600 KN. Adopt M-30 Grade concrete and Fe 415 grade steel. Permissible bearing stress in concrete is 8N/mm 2. Sketch the details of reinforcements in the rocker bearing. 10

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