Stone
Stones are a part of rock and have using in the building
construction such as blocks in masonry walls, slabs in flooring, roofing
slates, aggregates in concrete, terrazzo
in floor finishes, rock wool for insulation,
Stone Masonry Buildings is a traditional form of
building construction where the stone is locally available and can be used for
the construction purpose. Stone masonry has been used in the construction of
the monuments and structures around the world. Stone masonry buildings have an
earthquake-resistance structure that mostly can be found in the
earthquake-prone region and country including Mediterranean, Europe, North
Africa, the Middle East and Southeast Asia. Example of stone masonry around the
world as shown in the figure:
Stone
Masonry Walls
Stone masonry walls
are constructed by the method of the stone boulders bonder together with
mortar. Alternatively, the dry stone masonry is used when the stones are flat
in shape and no mortar is being used.
Types
of stone and mortal for the purpose of construction of the wall
Stone
boulder from the various sources such as river stones, field stones, and
quarries stones can be use in the stone masonry construction. River stone or
field stone are often used in their natural round or irregular forms.
Round
stone boulders used for traditional stone masonry
construction in Padang, Indonesia (photo: J.
Bothara)
In
sometimes, the stone have to shaped by the artisan stone-cutter to produce
semi-dressed stones which have at least one exterior flat surface. Such as
shown in this figure below:
In some
cases, the stones can be fully dressed into regular shape to suit the
construction purpose such as shown in the figure below:
Dressed
Stone Masonry (Ashlar Masonry) that look like solid blok
Dressed
stone masonry is constructed using regular shape of stone as shown in figure
below:
Delaminating
stone masonry walls
The stone masonry walls will be collapse
if not proper constructed. The causes of
delamination is due to the increase
in internal lateral pressure from the soil or rubble core of the wall, which
pushes the wall wythes outward
A)
B)
a) Delamination of
stone masonry walls: a) delamination in progress (source: Murty 2005),
and b) delamination of wall wythes due to the 1993
Maharashtra, India, earthquake (photo: S. Brzev)
Delamination of stone masonry
walls: a) two-wythe stone wall with a rubble core;
b) Stones are displaced due to
vibrations; c) internal lateral pressure due to rubble fills increases,
And d) the wall collapses (source: Meyer et al.
2007)
However, Stone
masonry building perform more well in the seismic area with the reinforced
concrete band such as shown in the figure below that provide the strengthen to
the stone masonry of the building.
The figure shown about the Reinforcement layout in
RC bands.
Earthquake Resistance in construction of stone wall
The Incas used a mortarless
construction with irregularly shaped rocks to build a wall. This construction
is place the rocks together such like a jigsaw puzzle. They also carved or
grinded the rock surfaces that met to have concave and convex surfaces to
allow shaping the rocks to fit together on the wall surface.
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| Wall at Machu Picchu. |
Wall at Sacsayhuaman.
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| Wall at Ollantaytambo. |
This type of construction of
wall by using the stone is very resistant to earthquakes: The lack of mortar
allows rocks to move independently during occurrences of earthquake. Besides that,
the rocks were irregularly shaped that allow the rock to fall back or fit into
their proper place as the earthquake subsided.
While, the Spanish using a brick and mortar
for their construction. This has a few advantage which is more easier and quicker
to build, but would collapse during earthquake. For example, in Cusco the
Spanish church built on top of Qoricancha was destroyed by an earthquake in
1950. The Incan foundation remained untouched.
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