Page 82 - Jabalpur_EQ

Mud&Village Houses
Chapter 4

Figure 4-4. Partial collapse and movement of gable wall resulting in partial col-
lapse of the roof at Koshamghat.

during the earthquake rather than the entire house to act as a one integrated unit.
The separation of walls cam be seen in Figs. 4-1 to 4-3. The integration of walls can
be easily achieved either through the use of a band (say, at lintel level) or by at
least employing L- shaped anchorages at corners (ISET 1989).

Damage to Gable Walls
Masonry gable walls have been known to perform badly in lateral loading. The
roofs sloping in both directions are preferable from the seismic considerations. It
has been recommended that gable ends must have the upper triangular portion
of masonry confined in a band, with a horizontal part continuous with'eaves level
band on longitudinal walls (ISET 1989).

Unfortunately, a large amount of damage in the Jabalpur earthquake was due to
absence of the triangular band of any kind. In fact, neither this triangular band
nor the eaves level band was found in most constructions in Jabalpur area. Figure
4-4 shows the movement and damage to the gable wall of a primary school build-
ing at Koshamghat which even caused the partial collapse of the roof. The 350
mm thick gable wall was constructed in mud fmoorum) mortar. More severe dam-
age can be seen in Figs. 4-5 and 4-6, which also have bricks laid in mud mortar.

Jabalpur Earthquake of May 22, 1997 72