BNBC 2020 REVIEW

The new edition of Bangladesh’s building code is the Bangladesh National Building Code 2020 (BNBC 2020). It is revised by expert panel in relevant fields. This code closely resembles ASCE 7-05.Structural engineering professionals, architects, electrical engineers, fire protection designers, plumbing engineers , mechanical engineers and planners who wish to work in Bangladesh need BNBC 2017 for the design and construction of infrastructures. While there are some errors in BNBC 2020, it is very useful and helpful for Bangladesh practicing qualified engineers. Earthquake load and wind load, if compared to BNBC 2006, have been substantially revised.

Click to Get “BNBC 2020 pdf Short Note“

THE VERSION OF BANGLADESH NATIONAL BUILDING CODE :

> BNBC 2020

> BNBC 2017

> BNBC 2006

— BNBC 2006 first appeared in 1993 but was released as BNBC 2006 in 2006.

SCOPE OF BNBC (BANGLADESH NATIONAL BUILDING CODE) :

— The provisions of this Code shall extend to the design , construction, usage or occupation, modification, movement, demolition and repair of any building or structure and any equipment installed or related therein or attached therein, except as otherwise provided for in other laws and regulations governing and regulating buildings.

–If, in any event, various parts of this Code have different specifications for materials , design or construction methods, or other conditions, then the most restrictive specification shall be governed.

— The special provision shall be applicable in the event of any discrepancy between a general requirement and a particular requirement.

— All references to part, chapter or section numbers or sections not explicitly defined by number shall be construed as referring to that part, portion, section or provision of this Code, unless clearly specified otherwise in this Code.

TABLE OF CONTENT OF BNBC 2020

VOLUME I

Part 1: Scope and Definition

Part 2: Administrations and Enforcement

Part 3: General Building Requirements, Control and Regulation

Part 4: Fire Protection

Part 5: Building Materials

VOLUME II

Part 6: Structural Design

Chapter 1 Definitions and General Requirements

Chapter 2 Loads on Buildings and Structures

Chapter 3 Soils and Foundations

Chapter 4 Bamboo

Chapter 5 Concrete Material

Chapter 6 Strength Design of Reinforced Concrete Structures

Chapter 7 Masonry Structures

Chapter 8 Detailing of Reinforcement in Concrete Structures

Chapter 9 Pre-stressed Concrete Structures

Chapter 10 Steel Structures

Chapter 11 Timber Structures

Chapter 12 Enforcement Structures

Chapter 13 Steel-Concrete Composite Structural Members

VOLUME III

Part 7: Construction Practices and Safety

Part 8: Building Services

Part 9: Alteration, Addition to and Change of Use of Existing Buildings

Part 10: Signs and Outdoor Display

APPENDIX OF BNBC 2020

SEISMIC ZONE CO-EFFICIENT

ZONE	COEFFICENT (g)
I	0.12
II	0.20
III	0.28
IV	0.36

Source: BNBC 2020

Table 6.2.16: Site Dependent Soil Factor and Other Parameters Defining Elastic Response Spectrum


Soil type	S	TB(s)	TC (s)	TD (s)
SA	1	0.15	0.4	2
SB	1.2	0.15	0.5	2
SC	1.15	0.2	0.6	2
SD	1.35	0.2	0.8	2
SE	1.4	0.15	0.5	2

Table 6.C.1: Spectral Response Acceleration Parameter SS and S1 for Different Seismic Zone


Zone–>	1	2	3	4
Ss	0.3	0.5	0.7	0.9
S1	0.12	0.2	0.28	0.36

BNBC ASSOCIATED WITH DIFFERENT CODE:

RCC design:

· ACI 318-08

Steel design:

· AISC 360-05

Seismic Loads:

· Eurocode 8

· Alternatively in software ASCE 7-05 using Appendix C of BNBC 2017

Wind Loads:

· ASCE 7-05

LOAD COMBINATION FOR DIFFERENT DESIGN PROCESS

Load combination for structural design (LRFD)

· — 1.4D

· — 1.2D + 1.6 L + 0.5L_r

· — 1.2D + 1.6L_r + L

· — 1.2D + 1.6Lr +0.8W

· — 1.2D + 1.6W + L

· — 1.2D + 1.6W + L+0.5L_r

· — 1.2D + 1.0E + 1.0L

· — 0.9D + 1.6W

· — 0.9D + 1.0E

D= Dead Loads, L= Normal Live Loads, L_r= Roof Live Loads, E= Earthquake Loads, W= Wind Loads

Also we have to consider the following load combination for structural design

— Have to consider in design for vertical earthquake load

— Vertical deflection for Gravity load

-D+L

— Creep, settlement and long term effect

– D+0.5L

— Lateral deflection for wind load of building

– D+0.5L+ 0.7W

CONCLUSION:

Civil engineers will review BNBC 2020 and practice it to create safer and more sustainable Bangladesh.

BNBC 2020 REVIEW - BANGLADESH NATIONAL BUILDING CODE

BNBC 2020 REVIEW

THE VERSION OF BANGLADESH NATIONAL BUILDING CODE :

SCOPE OF BNBC (BANGLADESH NATIONAL BUILDING CODE) :

TABLE OF CONTENT OF BNBC 2020

LOAD COMBINATION FOR DIFFERENT DESIGN PROCESS

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