Verticle load analysis according to BNBC 2020

Vertical Load
Zahid Hasan Khan
Executive Engineer
PWD Design Division 05, 28th BCS
&
Deputy Project Manager, BSPP
zahid.zahid23@yahoo.com
01749 765 355

Loads that act on structures can be divided into following categories:
Zahid Hasan Khan, Executive Engineer, PWD Design Division 05, 28th BCS, zahzahid.zahid23@gmail.com
01749 765 355
Classification of Loads
 Lateral loads Such as:
1) Wind Load
2) Earthquake Load
 Dead loads ( Self Weight, Floor Finish, Partition Wall)
 Live loads, and

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Classification of Loads

 Dead loads are those that are constant in magnitude and fixed in location throughout the
lifetime of the structure.
 Usually the major part of the dead toad is the weight of the structure itself.
i. weight of the member itself,
ii. weight of all materials of construction incorporated into the building
iii. weight of permanent partitions,
iv. weight of fixed service equipment
v . net effect of pre stressing.
 For buildings finish floors, and plastered ceilings are usually included as dead loads, and an
allowance is made for suspended loads such as piping and lighting fixtures.
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Dead Load
Art 2.2 Dead Loads

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Weight of Materials ( Art 2.2.4 ) 1 Kn/m3 = 6.366 P/ft3

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DEAD LOADS
Slab Thickness 6” So, SW = 6/12 X γ con Ksf
Beam Size : 12” X18”
So, SW = (12X18) X γ con K/ft
144
Column Size : 12” X18”
Floor Height : 10’-0”
SW =(12X18)X γ con X10 Kip
144
 SW from Material Property

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Dead Load

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DEAD LOADS
 When partition walls are indicated on the plans, their weight shall be considered as
dead load acting as concentrated line loads in their actual positions on the floor.
 The loads due to anticipated partition walls, which are not indicated on the plans,
shall be treated as live loads and determined in accordance with Sec 2.3.6
 Art 2.2.5 Weight of Permanent Partitions
Weights of fixed service equipment and other permanent machinery, such as
 electrical feeders and other machinery,
 heating,
 ventilating and
 air-conditioning systems,
 lifts and escalators,
 plumbing stacks and risers etc.
 2.2.6 Weight of Fixed Service Equipment

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Dead Load
In evaluating the final dead loads on a structural member for design purposes,
allowances shall be made for additional loads resulting from the
(i) difference between the prescribed and the actual weights of the members
and construction materials;
(ii) inclusion of future installations;
(iii) changes in occupancy or use of buildings; and
(iv) inclusion of structural and non-structural members not covered in Sections
2.2.2 and 2.2.3.
2.2.7 Additional Loads

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Art 2.3 LIVE LOADS
Art 2.3.3 MINIMUM FLOOR LIVE LOADS
The minimum floor live loads shall be the greatest actual imposed loads resulting from
the intended use or occupancy of the floor, and shall not be less than the uniformly
distributed load patterns specified in Sec 2.3.4 or the concentrated loads specified in Sec
2.3.5 whichever produces the most critical effect. The live loads shall be assumed to act
vertically upon the area projected on a horizontal plane
Art 2.3.4 Uniformly Distributed Loads
The uniformly distributed live load shall not be less than the values listed in Table 6.2.3,
reduced as may be specified in Sec 2.3.13, applied uniformly over the entire area of the
floor, or any portion thereof to produce the most adverse effects in the member concerned

Art 2.3 LIVE LOADS
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1 Kn/m2 = 20.88 P/ft2
 Minimum Uniformly Distributed Load Art 2.3.4

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Example -1
 Architectural Plan
60 Psf
100 Psf
100 Psf

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Example -1
 Architectural Plan
100 Psf
40 Psf
40 Psf
40 Psf
100 Psf
40 Psf

Art 2.3 LIVE LOADS
1 Kn/m2 = 20.88 P/ft2
Art 2.3.5 Concentrated Loads

Art 2.3 LIVE LOADS
Art 2.3.6 Provision for Partition Walls
When partitions, not indicated on the plans, are anticipated to be placed on the floors, their
weight shall be included as an additional live load acting as concentrated line loads in an
arrangement producing the most severe effect on the floor, unless it can be shown that a
more favourable arrangement of the partitions shall prevail during the future use of the floor.
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In the case of light partitions, wherein the total weight per metre run is not greater than 5.5
kN, a uniformly distributed live load may be applied on the floor in lieu of the concentrated
line loads specified above. Such uniform live load per square metre shall be at least 33% of the
weight per metre run of the partitions, subject to a minimum of 1.2 kN/m2

Art 2.3 LIVE LOADS
1 Kn/m2 = 20.88 P/ft2
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Art 2.3.8 Minimum Roof live Loads

Art 2.3 LIVE LOADS
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Art 2.3 LIVE LOADS
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Where Reduction is applicable ?
As in Article 2.3.13.1 Part 6, Chapter 2, Vol 2 BNBC 2020
 members for which a value of KLLAT is 37.16 m2 ( 400 Sft) or
 more are permitted to be designed for a reduced live load in accordance with the following
formula:
Where,
L = reduced design live load per m2 of area supported by the member;
KLL= live load element factor (Table 6.2.7Part 6, Chapter 2, Vol 2 BNBC 2020)
AT = tributary area in m2
L shall not be less than 0.50L0 for members supporting one floor
L shall not be less than 0.40L0 for members supporting two or more floors.

Art 2.3 LIVE LOADS
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Example Live Load

Art 2.3 LIVE LOADS
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 Example Live Load Reduction:
Building Information
 Building Location: Tangail
 No of Story: 8 stories
 Building Plinth Area: 2545 m2 (27387 ft2) ;
 Total Height of The Building: 29.25 m (96 ft)
 Use of The Building: Institutional
 Type of Structure: Moment Resisting Frame System without Shear wall.

Art 2.3 LIVE LOADS
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Art 2.3 LIVE LOADS
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 Example Live Load Reduction:  Member Property: Slab = 5”, Beam =
10X18, GB = 10 X 18, Column = 12 X 18
 Dead & Live Loads:
SW = 62.5 Psf ,
Floor finish = 20 psf,
Brick Wall = 0.425 K/ft,
Live load = 40 psf,

Art 2.3 LIVE LOADS
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Reduction of Live Loads
AT = 14’-0” X 14’-2” = 198.24 Sft = 18.42 m2 < 37.16 m2 .
So Reduction is need not be applied to 1st Floor.
The sum of tributary area at 2nd floor will be (18.42+18.42) = 36.84 m2 < 37.16 m2 .
So Reduction is need not be applied to 2nd Floor.
The sum of tributary area at 3rd floor will be (18.42+18.42+18.42) = 55.26 m2 > 37.16 m2 .
So Reduction will be applied to 3rd Floor.

Art 2.3 LIVE LOADS
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L = 31.41 Psf
= 78.24 % Lo Can be applied ( or 31.29 Psf)
So Reduction will be 21.76 %
At Ground Floor, 1st Floor Live Load is 40 Psf
At 2nd Floor 31.41 Psf
At 3rd & 4t Floor 31.41 PSf
At 5th Floor 24.57 Psf

Verticle load analysis according to BNBC 2020

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Verticle load analysis according to BNBC 2020