Page 28 - EQTips_Eng

Learning

14 Earthquake Design
Earthquake Tip and

Construction

Why are Horizontal Bands necessary in Masonry Buildings?

Role of Horizontal Bands flat timber or CGI sheet roof, roof band needs to be
Horizontal bands are the most important provided. In buildings with pitched or sloped roof, the
earthquake-resistant feature in masonry buildings. The roof band is very important. Plinth bands are
bands are provided to hold a masonry building as a primarily used when there is concern about uneven
single unit by tying all the walls together, and are settlement of foundation soil.
similar to a closed belt provided around cardboard The lintel band ties the walls together and creates
boxes. There are four types of bands in a typical a support for walls loaded along weak direction from
masonry building, namely gable band, roof band, lintel walls loaded in strong direction. This band also
band and plinth band (Figure 1), named after their reduces the unsupported height of the walls and
location in the building. The lintel band is the most thereby improves their stability in the weak direction.
important of all, and needs to be provided in almost all During the 1993 Latur earthquake (Central India), the
buildings. The gable band is employed only in intensity of shaking in Killari village was IX on MSK
buildings with pitched or sloped roofs. In buildings scale. Most masonry houses sustained partial or
with flat reinforced concrete or reinforced brick roofs, the complete collapse (Figure 2a). On the other hand, there
roof band is not required, because the roof slab also was one masonry building in the village, which had a
plays the role of a band. However, in buildings with lintel band and it sustained the shaking very well with
hardly any damage (Figure 2b).
Roof
Masonry
above lintel
Lintel Band

Masonry
below lintel

Wall
Plinth Band
Foundation

Soil
(a) Building with Flat Roof

(a) Building with no horizontal lintel band:

Gable-roof collapse of roof and walls
connection
Gable
Band Band Truss-wall
Roof
connection

Floor-walls Lintel
connection Band

Lintel
Band

Plinth Cross wall (b) A building with horizontal lintel band in Killari
Band connection village: no damage
Peripheral wall
connection
Figure 2: The 1993 Latur Earthquake (Central
(b) Two-storey Building with Pitched Roof India) - one masonry house in Killari village had
Figure 1: Horizontal Bands in masonry building – horizontal lintel band and sustained the shaking
Improve earthquake-resistance. without damage.

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