Page 33 - EQTips_Eng

IITK-BMTPC Earthquake Tip 16

How to make Stone Masonry Buildings Earthquake-Resistant? page 2
(a) Ensure proper wall construction The wall thickness resistance, its extensive use is likely to continue due to
should not exceed 450mm. Round stone boulders tradition and low cost. But, to protect human lives and
should not be used in the construction! Instead, the property in future earthquakes, it is necessary to
stones should be shaped using chisels and follow proper stone masonry construction as described
hammers. Use of mud mortar should be avoided in above (especially features (a) and (b) in seismic zones
higher seismic zones. Instead, cement-sand mortar III and higher). Also, the use of seismic bands is highly
should be 1:6 (or richer) and lime-sand mortar 1:3 (or recommended (as described in feature (c) above and in
richer) should be used. IITK-BMTPC Earthquake Tip 14).
(b) Ensure proper bond in masonry courses: The masonry
Discontinuities in lintel
walls should be built in construction lifts not Horizontal band should be avoided
exceeding 600mm. Through-stones (each extending Lintel Band
over full thickness of wall) or a pair of overlapping
bond-stones (each extending over at least ¾ths
thickness of wall) must be used at every 600mm
along the height and at a maximum spacing of 1.2m
along the length (Figure 3).

Wall
Alternatives to
Section Through Stones
Wood
plank
< 600mm Hooked
steel link
S-shaped
steel tie

< 600mm <450mm
Wall
Floor
Level Plan Figure 4: Horizontal lintel band is essential in

random rubble stone masonry walls –
provides integrity to the dwelling, and holds the
Pair of overlapping stones <1200mm walls together to resist horizontal earthquake
(each of length at least
Bond

¾ths the wall thickness) stone effects.

Related - Earthquake Tip
Tip14: Why horizontal bands are required in masonry buildings?
<1200mm <1200mm
<400mm Reading Material
Figure 3: Use of “through stones” or “bond Brzev,S., Greene,M. and Sinha,R. (2001), “Rubble stone masonry

stones” in stone masonry walls – vital in walls with timber walls and timber roof,” World Housing
18,
India/Report
Encyclopedia
(www.world-housing.net),
preventing the wall from separating into wythes. published by EERI and IAEE
IAEE, (1986), Guidelines for Earthquake Resistant Non-Engineered
(c) Provide horizontal reinforcing elements: The stone Construction, The ACC Limited, Thane, 2001 (See www.niceee.org).
masonry dwellings must have horizontal bands IS 13828, (1993), Indian Standard Guidelines - Improving Earthquake
(See IITK-BMTPC Earthquake Tip 14 for plinth, lintel, Resistance of Low-Strength Masonry Buildings, Bureau of Indian
Standards, New Delhi
roof and gable bands). These bands can be Publications of Building Materials and Technology Promotion Council,
constructed out of wood or reinforced concrete, and New Delhi (www.bmtpc.org):
chosen based on economy. It is important to (a) Retrofitting of Stone Houses in Marathwada Area of Maharashtra
provide at least one band (either lintel band or roof (b) Guidelines For Improving Earthquake Resistance of Housing
(c) Manual for Repair and Reconstruction of Houses Damaged in
band) in stone masonry construction (Figure 4). Earthquake in October 1991 in the Garhwal Region of UP
(d) Control on overall dimensions and heights: The
unsupported length of walls between cross-walls Authored by:
should be limited to 5m; for longer walls, cross C.V.R.Murty
supports raised from the ground level called Indian Institute of Technology Kanpur
buttresses should be provided at spacing not more Kanpur, India
than 4m. The height of each storey should not Sponsored by:
exceed 3.0m. In general, stone masonry buildings Building Materials and Technology Promotion
should not be taller than 2 storeys when built in Council, New Delhi, India
cement mortar, and 1 storey when built in lime or
mud mortar. The wall should have a thickness of at This release is a property of IIT Kanpur and BMTPC New
least one-sixth its height. Delhi. It may be reproduced without changing its contents
Although, this type of stone masonry construction and with due acknowledgement. Suggestions/comments
may be sent to: nicee@iitk.ac.in. Visit www.nicee.org or
practice is deficient with regards to earthquake www.bmtpc.org, to see previous IITK-BMTPC Earthquake Tips.

32