Under the guidance of Mr. Debaraj Bailung Sonowal

PRESENTED BY :- Susmit Baruah( CIB12021) Kamal Singh (CIB12046) Roshan Kumar (CIB12054) Kumar Aman (CIB12058) Ravindra Kumar Verma (CIB12060)

Objectives

The Objectives of the Project are:-

To carry out complete analysis and design of the main structural elements of a multi-storey building including beam, column, slab, foundation etc.

To compare manual results with the results of structural analysis and design software SAP 2000.

To get real life experience with engineering practices.

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A (G+3) R.C. residential building is adopted for analysis & design.

Ground floor is open space for parking & floors 1st to 3rd are residential blocks.

The location of the building is assumed at Guwahati(Zone V).

Gravity load analysis is done by Kani’s method while earthquake analysis by Portal frame method.

For concrete design, IS 456:2000 is considered & for ductile detailing IS 13920:1993 is followed.

Seismic analysis is carried out as per IS 1893(part1): 2002.

Design of beam & column are carried out as per design aid SP 16.

PlanPlan

6

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ElevationElevationOur project is a residential building in Guwahati, which consists ofParking plots & three repeated residential blocks shown below.

Building size: 20.4*22.60 square metre. Front setback =4.5m Rear setback=4.5m Side setback=2.4m Plot size : 29.4x27.4 m2

Total plot area =805.56 sq. m. Percentage occupied space= 57.2% Percentage of free space=42.8% Tread of stairs is 0.23m Rise of stairs is 0.16m

Minimum plot size : 803 sq. m. in high and medium density and 1338 sq. m. for low density zone.

Maximum coverage : 50% Minimum front setback : 4.5 m Minimum rear setback : 4.5 m Minimum side setback : 2.4 m

Grade of concrete – M25 , grade of steel – Fe 450. Floor to floor height – 3.1 m Plinth height above GL – 0.9 m Depth of foundation below GL – 3.0 m Parapet Wall height – 1.0 m Slab thickness- 150 mm External wall thickness – 250mm , internal wall thickness- 150mm. Size of column – 500mm x 500mm . Size of beam – 300mm x 450mm. Live load on floor – 3 kN /m2 , Live load on roof – 3.0 kN/m2

Roof treatment & floor finish (F.F.) – 1.0 kN/m2

Site located on Seismic Zone V , Building resting on Medium Soil. Building frame type is Special Moment Resting Frame. Density of concrete -25 kN/m3 , Density of masonary wall – 20 kN/ m3

Bearing capacity of fuundation soil= 100kN/m2

Load calculation

Load distribution

Shear force, bending moment & axial load calculation

Seismic analysis

Dead load

Live load

Seismic load

Dead load

Load due to self wt. of beam, column, slab,wall etc

D.L.=self wt.+F.F. Live load

load that may change its position. eg- load of human, furniture etc.

Live load assumed is 3kN/m2 .

Earthquake load

Equivalent static method has been used to find design lateral load.

Portal frame method has been used for analysis.

Based on IS:1893(part 1)guidelines, the following load combinations has been used in the analysis.

1.5*(D.L.+L.L.)

1.2*(D.L.+L.L.+E.L.)

Effect of resultant moment will be maximum along the short span. So analysis & design has been carried out along short span.

Design lateral force on the structure that are exerted due to earthquake is calculated.

Moment & axial load is calculated using Portal method, which is based on following assumptions:-

Point of contraflexure occurs at the middle of all the members of the frame.

Horizontal shear taken by each interior column is double of that taken by exterior column

Design moment, Mu is calculated.

Mu,lim is found using Mu,lim=0.138fckbd2.

Compare Mu & Mu,lim.

If Mu<Mu,lim => design as singly reinforced.

For singly reinforced, find Pt corresponding to M25 & Mu/bd2.

If Mu>Mu,lim => design doubly reinforced.

For doubly reinforced, find Pt & Pc corresponding to M25, d’/d, & Mu/bd2.

Stirrup is designed as per IS13920:1993.

Unsupported length is calculated.

Slenderness ratio is compared in x & y. [Lex/Dx=KxLx/Dx & Ley/Dy]

Minimum eccentricity is calculated in x & y. [exmin=(Lx/500)+(Dx/30) & eymin]

Factored load on column is found.

Area of steel is calculated using Pu = 0.4fckAg+ As(0.67fy- 0.4fck ).

Lateral ties & its spacing is found.

Appropriate clear cover & developmental length are provided.

Ductile detailing is done & confining reinforcement is provided.

Cross-sectional detailing

Ductile detailing

Due to low soil bearing capacity of 100kN/m2 ,we have go for deep foundation design.

IS 2911 –part 1/sec 2,code of practice for design and construction of pile foundation , concrete pile- bored cast in situ.

IS 456-2000 Pile foundations shall be designed in such a way that the load

from the structure can be transmitted to the sub-surface with adequate factor of safety against shear failure of sub-surface and without causing such settlement , structural damage.

Size of footing =2.4m*2.4m◦ Diameter of pile(Dp)=300mm◦ Pile overhang provided=2*Dp=600mm

Thickness of footing◦ Caluclation is based on shear◦ -One Way shear plane◦ -Two Way shear plane

Arround column Arround piles

Deaign of flexural reinforcementTransfer of forces at column baseTransfer of force at pile-pile cap interface

x x

PLAN

Section XX

Pile is designed as long column

Mazor part of load must be transferred through concrete shear.

•One way slab •Two way slab

Numbering of slab

The maximum positive and negative moments per unit width in a slab are determined from Mx=xwlx

2 My= ywlx

2

where α x,αy and are coefficients given in Table 26 of IS 456

Sectional view of slab reinforcementSectional view of slab reinforcement

Calculation of Effective span/depth ratio.

Determination of load activating over each tread width(w kN/m).

Designed factored load per unit projected length of the staircase (1.5w/tread kN/mm2)

Bending moment calculation.

Calculation of area of the main steel.

Provision of Distribution steel [(0.0012b*t(tread) for Fe415]

Check for shear.

Check for deflection.

Load diagram

Reinforcement detailing

If earthquake load is considered, moment on structure will be greater than as compared to only gravity load.

As earthquake load has been considered in this project, so the required moment will be greater.

Building is a regular G+3 multistoried building, the method of equivalent static method is holding good.

For very high rise building, dynamic load analysis should be considered.

In general, the type of foundation depends on the soil condition of the site.

So as per the assumed soil bearing capacity & soil profile, the pile foundation is best suitable. Hence pile foundation is considered in this project.

Dynamic load analysis.

Comparison of result with the software analysis

Cost estimation