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IITK-BMTPC Earthquake Tip 11

What are the Indian Seismic Codes? page 2
The revised 2002 edition, Part 1 of IS1893, contains IS 13935, 1993
provisions that are general in nature and those These guidelines cover general principles of
applicable for buildings. The other four parts of IS seismic strengthening, selection of materials, and
1893 will cover: Liquid-Retaining Tanks, both elevated techniques for repair/seismic strengthening of
and ground supported (Part 2); Bridges and Retaining masonry and wooden buildings. The code provides a
Walls (Part 3); Industrial Structures including Stack- brief coverage for individual reinforced concrete members
Like Structures (Part 4); and Dams and Embankments in such buildings, but does not cover reinforced concrete
(Part 5). These four documents are under preparation. frame or shear wall buildings as a whole. Some
In contrast, the 1984 edition of IS1893 had provisions guidelines are also laid down for non-structural and
for all the above structures in a single document. architectural components of buildings.
Provisions for Bridges

Seismic design of bridges in India is covered in In Closure…
three codes, namely IS 1893 (1984) from the BIS, IRC 6 Countries with a history of earthquakes have well
(2000) from the Indian Roads Congress, and Bridge developed earthquake codes. Thus, countries like
Rules (1964) from the Ministry of Railways. All Japan, New Zealand and the United States of America,
highway bridges are required to comply with IRC 6, have detailed seismic code provisions. Development of
and all railway bridges with Bridge Rules. These three building codes in India started rather early. Today,
codes are conceptually the same, even though there India has a fairly good range of seismic codes covering
are some differences in their implementation. After the a variety of structures, ranging from mud or low-
2001 Bhuj earthquake, in 2002, the IRC released strength masonry houses to modern buildings.
interim provisions that make significant However, the key to ensuring earthquake safety lies in
improvements to the IRC6 (2000) seismic provisions. having a robust mechanism that enforces and
implements these design code provisions in actual
IS 4326, 1993 constructions.
This code covers general principles for earthquake
resistant buildings. Selection of materials and special Related Tip
features of design and construction are dealt with for Tip 4: Where are the seismic zones in India?
the following types of buildings: timber constructions, Tip 8: What is the seismic design philosophy of buildings?
Tip 9: How to make buildings ductile for good seismic performance?
masonry constructions using rectangular masonry Tip 10: How flexibility of buildings affects their earthquake
units, and buildings with prefabricated reinforced response?
concrete roofing/flooring elements.
Reading Material
IS 13827, 1993 and IS 13828, 1993 BMTPC, (2000), Guidelines: Improving Earthquake Resistance of Housing,
Guidelines in IS 13827 deal with empirical design Building Materials and Technology Promotion Council, New
Delhi
and construction aspects for improving earthquake- Bridge Rules, (1964), Rules Specifying the Loads for the Design of Super-
resistance of earthen houses, and those in IS 13828 with Structure and Sub-Structure of Bridges and for Assessment of the
general principles of design and special construction Strength of Existing Bridges, Government of India, Ministry of
Railways (Railway Board)
features for improving earthquake resistance of IRC 6, (2000), Standard Specifications and Code of Practice for Road
buildings of low-strength masonry. This masonry Bridges - Section II: Loads and Stresses, Indian Roads Congress, New
includes burnt clay brick or stone masonry in weak Delhi
mortars, like clay-mud. These standards are applicable IS 456, (2000), Indian Standard Code of Practice for Plain and Reinforced
Concrete, Bureau of Indian Standards, New Delhi.
in seismic zones III, IV and V. Constructions based on SP 22 (S&T), (1982), Explanatory Handbook on Codes for Earthquakes
them are termed non-engineered, and are not totally Engineering - IS 1893:1975 and IS 4326:1976, Bureau of Indian
free from collapse under seismic shaking intensities Standards, New Delhi
VIII (MMI) and higher. Inclusion of features
mentioned in these guidelines may only enhance the
seismic resistance and reduce chances of collapse. Authored by:
C.V.R.Murty
IS 13920, 1993 Indian Institute of Technology Kanpur
In India, reinforced concrete structures are Kanpur, India
designed and detailed as per the Indian Code IS 456 Sponsored by:
(2002). However, structures located in high seismic Building Materials and Technology Promotion
regions require ductile design and detailing. Provisions Council, New Delhi, India
for the ductile detailing of monolithic reinforced
concrete frame and shear wall structures are specified This release is a property of IIT Kanpur and BMTPC New
in IS 13920 (1993). After the 2001 Bhuj earthquake, this Delhi. It may be reproduced without changing its contents
code has been made mandatory for all structures in and with due acknowledgement. Suggestions/comments
zones III, IV and V. Similar provisions for seismic may be sent to: nicee@iitk.ac.in. Visit www.nicee.org or
www.bmtpc.org, to see previous IITK-BMTPC Earthquake Tips.
design and ductile detailing of steel structures are not
yet available in the Indian codes.

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