Multi-storey commercial building design

Structural Analysis And Design of Multi-storeyed Building

Project members:

Rajesh Dhakal (066/BCE/57)

Sandeep Shrestha (066/BCE/70)

Santanu Shrestha (066/BCE/73)

Shyam Kumar Sinkemana (066/BCE/80)

Supervisor:Asst. Prof. Prachand Man Pradhan

Objectives

• Learn the concept of lateral and vertical loading on the building.

• Identification of structural arrangement of the plan.

• Modeling of the building for the structural analysis.

• Detail structural analysis using SAP 2000.• Sectional design of structural components.• Structural detailing of members and the system.

Major Scope

• Seismic coefficient method is used• Code of practices: IS456:2000, IS875:1987(Part

1,2), IS1893:2000, IS13920:1993, SP16,SP34• The bearing capacity of foundation is assumed

to be 140 kN/m2.• The project does not take into account the soil

pressure in elements at the basement as well as the possible impact loads due to vehicles

Salient Features

• Name: Bharbhacho Complex• Location: Dhudhpati, Bhaktapur• Building Type: Commercial• System: RCC framed Structure• No. of storeys: 7• Floor ht: 3.3m• Foundation type: Raft foundation

Preliminary Design

• Design of Slab :

as per deflection control

Slab Depth Effective depth (d) Total depth (D)

Without secondary beam

190 mm 220 mm

With secondary beam

120 mm 150 mm

Design of beam:as per deflection control

Beam type Width (b) Total depth (D)

Primary Beam 400 mm 550 mm

Secondary beam 250 mm 300 mm

• Design of column– Loaded from slab, wall, beam and self weight of

column considered– Factored load calculated– 20% EQ load considered– Equating total load with Puz=0.45fckAc+0.75fyAst

– Assuming Pt=3%

– Ag calculated and size of column adoptedColumn Type Dimension (B×D) mm2

Type I 400×400Type II 400×400Type III 500×500

Manual calculation

• Dead Load– Slab– Beam– Wall– column

• Live load• Centre of mass• Centre of rigidity• Eccentricity

SAP Analysis

Design of Structural members

• Design of Slab

Xm Ym Xs Ys

Ast required

112.25 98.04 141.51 132.27

Ast provided

452.36 376.967 376.967 376.967

Slab Detailing

Torsional Detail in Slab

Design of Staircase

StaircaseMain reinforcement Distribution bar Development length

Required Provided Required Provided Required Provided

Doglegged 12Φ 559c/c 12Φ 200 c/c 8 Φ@279c/c 8 Φ@270c/c 810 mm 820 mm

Openwell1st flight

12Φ391.65c/c

12Φ300 c/c 8 Φ@279c/c 8 Φ@270c/c 483 mm 485 mm

2nd flight 12Φ398.26 c/c

12Φ195c/c 8 Φ@279c/c 8 Φ@270c/c 600 mm 700 mm

Staircase Detailing

Design of Beam Beam Type

Support reinforcement Mid reinforcement

Top bar Bottom bar Top bar Bottom bar

Primary beam (400x550) 5-25 Φ 4-20 Φ 2-20 Φ 2-25 Φ

Stair beam (400x 550) 2-20 Φ 2-20 Φ 2-20 Φ 4-20 Φ

Secondary beam (250x300) 3-16 Φ 2-16 Φ 2-16 Φ 3-16 Φ

Beam Detailing

Contd.

Design of ColumnColumn Types Reinforcement percent

Small (400x400) 8-28 Φ 2.43 %

Big (600x600) 12-25 Φ 1.64 %

Ramp (500x600) 12-28 Φ 2.46 %

Column Detailing

Design of Basement wall

Reinforcement pattern Face ReinforcementVertical Both 16 mm Φ @ 190 mm

HorizontalFront 8 mm Φ @160 mmInner 8 mm Φ @320mm

Detailing of Basement wall

Design of Lift

Lift TypesVertical Reinforcement Horizontal Reinforcement

Required Provided Required Provided

Capsule 14 Φ @ 109.36 14 Φ @ 100 12 Φ @ 253.85 12 Φ @ 250

Middle capsule 14 Φ @ 331.14 14 Φ @ 320 12 Φ @ 253.85 12 Φ @ 250

Service 14 Φ @ 367.67 14 Φ @ 350 12 Φ @ 253.85 12 Φ @ 250

Lift Detailing

Design of FoundationShorter span reinforcement Longer span reinforcement

20 mmφ @ 175 mm c/c 20 mmφ @ 200 mm c/c

Raft Footing Detailing

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