DUCTILE DETAILING OF REINFORCEDCONCRETE STRUCTURES SUBJECTED TOSEISMIC FORCES -CODE OF PRACTICE
IS 13920 : 1993
About IS 13920 : 1993
This Indian Standard was adopted
by the Bureau of Indian Standards, after the draft finalized by the Earthquake
Engineering Sectional Committee had been approved by the Civil Engineering Division
Council. IS 4326 : 1976 Code of practice for earthquake resistant design and
construction of buildings’ while covering certain special features for the
design and construction of earthquake resistant buildings included some details
for achieving ductility in reinforced concrete buildings. With a view to keep
abreast of the rapid developments and extensive research that has been carried
out in the field of earthquake resistant design of reinforced concrete
structures, the technical committee decided to cover provisions for the
earthquake resistant design and detailing of reinforced concrete structures
separately.
This code incorporates a number of important
provisions hitherto not covered in IS 4326: 1976.
The major thrust in the formulation of this standard is one of the following lines:
a) As a result of the experience gained from the
performance, in recent earthquakes, of reinforced concrete structures that were
designed and detailed as per IS 4326 : 1976, many deficiencies thus identified
have been corrected in this code.
b) Provisions on detailing of beams and columns have
been revised with an aim of providing
them with adequate toughness and ductility so as to
make them capable of undergoing extensive inelastic deformations and
dissipating seismic energy in a stable manner.
c) Specifications on a seismic design and detailing
of reinforced concrete shear walls have been included.
The other
significant changes incorporated in this code are as follows:
a) Material specifications are indicated for lateral
force resisting elements of frames.
b) Geometric constraints are imposed on the cross
section for flexural members. Provisions on minimum and maximum reinforcement
have been revised. The requirements for detailing of longitudinal reinforcement
in beams at joint faces, splices, and anchorage requirements are made more
explicit. Provisions are also included for calculation of design shear force
and for detailing of transverse reinforcement in beams.
c) For members subjected to axial load and flexure,
the dimensional constraints have been imposed on the cross section. Provisions
are included for detailing of lap splices
and for the calculation of design shear force. A comprehensive set of
requirements is included on the provision of special confining reinforcement in
those regions of a column that are. expected to undergo cyclic inelastic
deformations during a severe earthquake.
d) Provisions have been included for estimating the
shear strength and flexural strength of shear wall sections. Provisions are
also given for detailing of reinforcement in the wall web, boundary elements,
coupling beams, around openings, at construction joints, and for the
development, splicing and anchorage of reinforcement.
Whilst the common methods of design and construction
have been covered in this code, special systems of design and construction of
any plain or reinforced concrete structure not covered by this code may be
permitted on production of satisfactory evidence regarding their adequacy for seismic
performance by analysis or tests or both. The Sectional Committee responsible
for the preparation of this standard has taken into consideration the view of
manufacturers, users, engineers, architects, builders and technologists and has
related the standard to the practices followed in the country in this field.
Due weightage has also been given to the need for international co-ordination
among standards prevailing in different seismic regions of the world.
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