Structural Analysis And Design of

Multi-storeyed Building

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 adopted

Column Type Dimension (B×D) mm2

Type I 400×400

Type II 400×400

Type 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

Staircase

Main 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

Openwell 1st flight

12Φ391.65

c/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 Column

Column 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 Reinforcement

Vertical Both 16 mm Φ @ 190 mm

Horizontal

Front 8 mm Φ @160 mm

Inner 8 mm Φ @320mm

Detailing of Basement wall

Design of Lift Lift Types

Vertical 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 Foundation Shorter span reinforcement Longer span reinforcement

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

Raft Footing Detailing

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