Design of Reinforced Concrete structures — Winter 2024

What is the basic design philosophy of seismic design of structures.

Explain the codal provision of Direct Design Method for Flat slab.

Amultistoried unbraced building as shown in Fig. 1 having 20m X 30m plan dimension and overall height of 30m is to be designed in Vadodara in developed outskirt area with scattered buildings of its height. Determine the designed wind pressure acting on the internal frame of building and draw the pressure diagram. Assume bay width 5m each, Ground storey height 5m, Roof parapet 1m high and remaining storey height 4m each. Life of building is 30 years. Fig. 1

Explain concept of capacity design of structures.

Draw neat sketches of behaviour of cylindrical tank for the following cases:

wall with fixed base and free top, subjected to triangular load (ii) wall with hinged base and free top, subjected to triangular load.

Aretaining wall is constructed to retain the earth 4m high. The top surface is horizontal behind the wall. The soil behind the wall is well drained medium dense sand with following properties: Unit Weight = 17 kN/m3, angle of internal friction, ϕ=300. The material under wall base is same as above with safe bearing capacity of 150 kN/m2. The coefficient of friction between the base and soil is 0.55. Use M20 grade and HYSD reinforcement of grade Fe 415. Determine the coefficient of earth pressure, base width. Determine the thickness of stem and base slab for the retaining wall mentioned.

Explain different types of irregularities in the buildings for analyzing the building for possible occurrence of strong ground motion.1

Explain ductile detailing criteria for spacing of links over the entire length of the beam.

Write a short note on (a) Structural Plan density (b) Plan aspect ratio of buildings.

Acounterfort retaining wall with height 6m, footing depth 1 m, with 450mm thick base having width 4.5m is constructed to retain the earth of 6m. The top surface is horizontal behind the wall. The counterforts are provided at a 3m c/c. The soil behind the wall is a well drained medium dense soil (unit weight = 16.2 kN/m3, angle of internal friction, ϕ=300; Safe bearing capacity of soil 150 kN/m2). The coefficient of friction between the base and soil is 0.6. Estimate the horizontal and vertical loads and moments. Wall is designed with grade M20 concrete and Fe 415 steel.

Which are the assumptions made to analyse the flat slab by the Equivalent Frame Method.

Explain the codal provision of Direct Design Method for Flat slab.

Explain the various types of retaining wall and their components with specific purpose and neat sketch.

Write a brief note on various types of structural system.

An isolated rectangular sloped footing for the columns of size 230mm X 650mm, reinforced with 6 bars of 20mm diameter and carrying an axial load of 1200kN. The bearing capacity of soil is 300 KN/m2. Take offset from face of the column equal to 50mm. Determine the dimensions of footing.

Explain the limit state method as applied to water retaining structures.

What are the different load combinations? Why are the multistoried buildings designed for various load combinations?

Determine the fundamental natural period of four storied MRF building 13.5m X 13.5m in plan and height of 16.25m, if (i) It is considered without masonry infill; (ii) It is considered with masonry infill.

Differentiate the flat slab and conventional slab-beam diaphragms? Explain with suitable examples.

Various types of Construction joints can be used in water tanks. Explain any two with neat with sketches.

Explain the mechanism of load transfer in multistoried (G+3 Story) buildings with suitable example.

Aslab of water retaining structure is 300 mm thick. Assuming that construction has movement joints placed at 13m c/c, and construction is being carried out in summer. Determine the maximum spacing of cracks and distribution of steel (or reinforcement for moisture and temperature) for the slab. The material is M30 grade concrete and grade of steel is Fe500.

Prepare structural layout and designate all the members like beams, columns and slabs, of G+3 building (entire structure) of having 4 bays of 5 m in X – direction and 4 bays of 3 m in Y-direction.

Enlist the minimum reinforcement criteria for the structures retaining liquid in context to IS 3370 (2021).

Explain ductile detailing of column as per IS: 13920 with sketch.