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Report # 72 : Traditional rural house in Kutch region of India (bhonga)

by Madhusudan Choudhary, Kishor S. Jaiswal, Ravi Sinha

The Bhonga is a traditional construction type in the Kutch district of the Gujarat state in India, which has a very high earthquake risk. A Bhonga consists of a single cylindrically shaped room. The Bhonga has a conical roof supported by cylindrical walls. Bhonga construction has existed for several hundred years. This type of house is quite durable and appropriate for prevalent desert conditions. Due to its robustness against natural hazards as well as its pleasant aesthetics, this housing is also known as “Architecture without Architects.” It performed very well in the recent M7.6 Bhuj earthquake in 2001. Very few Bhongas experienced significant damage in the epicentral region, and the damage that did occur can be mainly attributed to poor quality of the construction materials or improper maintenance of the structure. It has also been observed that the failure of Bhongas in the last earthquake caused very few injuries to the occupants due to the type of collapse.


Report # 52 : Adobe house

by Cesar Loaiza F., Marcial Blondet, Gianfranco Ottazzi

This is a traditional construction practice followed for over 200 years. Houses of this type can be found both in urban and rural areas in the coastal and highlands regions of Peru. Walls are made of adobe blocks laid in mud mortar. The roof structure is made of wood; it usually consists of timber beams with timber planks covered with a mud mortar overlay or with clay tiles or metal sheets. Houses of this type are mainly occupied by poor people. This construction is considered to be very vulnerable to earthquake effects.


Report # 46 : Unburnt brick wall building with pitched roof (nyumba ya zidina)

by Mauro Sassu, Ignasio Ngoma

This type of building is found both in urban and rural areas throughout Malawi. It is a construction type that is gaining popularity at the moment; it is estimated that it constitutes 45% of the country’s housing stock. The thatched roof is supported by unburnt mud brick walls built in mud mortar. The walls are built on a stone platform raised above ground as a protection against floods. These buildings are built without any horizontal and vertical reinforcement. As a result, the strength of the building is very low and it is considered to be very vulnerable to earthquake effects. In the 1989 Salima earthquake (magnitude 6), 9 people died and over 50,000 people were left homeless. Many buildings of this type suffered extensive damage or collapsed.


Report # 45 : Rammed earth house with pitched roof (Nyumba yo dinda OR Nyumba ya mdindo)

by Mauro Sassu, Ignasio Ngoma

This type of construction is used for residences only. The building technique consists of in-situ ramming of moist soil in a carefully aligned/placed mold. The mold dimensions are between (250 – 300 mm) wide X (400 – 450 mm) long X (200 – 300 mm) height. The plan of the house is rectangular. The roof is either grass thatch or iron sheets supported on timber poles. This type is found in all three regions of Malawi. The strength of the wall is low and depends on the compacting effort applied. The expected seismic performance is poor. There are no vertical or horizontal reinforcements.


Report # 43 : Rural mud wall building (nyumba yo mata OR ndiwula)

by Mauro Sassu, Ignasio Ngoma

This housing construction type is used only for residential purposes. The building technique consists of timber poles as the core or base with a mud smear (plaster) applied on both sides. The plan is circular (only one floor) and the roof is formed by grass thatch supported on timber poles and cross members. The circular shape of the plan and the light weight of the roof, combined with the wood skeleton or frame, ensure a good seismic response. The seismic vulnerability is increased by poor connections of the wood skeleton and by progressive damage to the natural components.


Report # 42 : Houses with mud walls and thatch roofs

by Svetlana Uranova, Ulugbek T. Begaliev

This building type is widespread in the rural areas of Kyrgyzstan, and also in some urban areas. It is a non-engineered construction. Due to its low cost, it is mainly used by poor people. Various building materials are used for this type of construction, e.g., clay and straw for the walls, wood for the roof structure, and stone for the foundations. In order to achieve adequate flexibility or plasticity, a small amount of clay is mixed with water. Straw is added to achieve an improved consistency. Small panel boards are used as formwork for casting mud walls. The walls are cast in lifts; a new lift is cast after the previous one has set. Windows and doors have wood lintels. Floors are made out of wood planks. Buildings of this type do not have any earthquake-resistant features and are considered to be highly vulnerable to seismic effects.


Report # 23 : Rural mud house with pitched roof

by Amit Kumar

This is a typical rural construction found throughout India, except in the high rainfall areas in the northeastern part of the country. It is a single-family house, mainly occupied by the poorer segment of the population. The main load-bearing system consists of mud walls, which carry the roof load. In some cases wooden posts are provided at the wall corners and at intermediate locations. The wooden posts and walls are not structurally integrated, and therefore the loads are shared by the walls and the frame. There are very few openings (doors and windows) in these buildings. In rural areas there are usually no windows at all. In general, this type of construction is built by the owners and local unskilled masons and the craftsmanship is very poor. This building type is classified as grade-A (most vulnerable) per the IAEE building classification and IS Code 1893:1984. This is a low-strength masonry construction and it is considered extremely vulnerable to seismic forces.


Report # 14 : Vivienda de Adobe (Adobe house)

by Manuel A. Lopez M., Julian Bommer, Gilda Benavidez

This housing type can be found in rural and urban areas. Rural: Adobe houses are generally small structures, 5 x 6 m in the plan, having load-resistant walls made of adobe bricks between 0.3 and 0.5 m thick. Usually, they are single-family (5-person) houses. Wood planks that support metal sheets covered by tiles sometimes constitute the roof. In some cases, the roof can be a thatched roof supported on wood purlins. Urban: Adobe houses are much bigger in urban areas than in rural areas. They are one-floor structures and their plans are 15 x 30 m or larger. The wall thickness can easily reach 1 m and wall height can reach 3 m or more. In both the cases mentioned above, the adobe housing type has performed badly in earthquakes. Its heavy roof sometimes can be its biggest weakness and its unreinforced walls make this house vulnerable to earthquake effects.


Report # 2 : Traditional Adobe House with Reinforcement

by Virginia I. Rodriguez, Maria I. Yacante, Sergio Reiloba

This construction type is a single-family house. In general, it is a single-storey building, an isolated construction found in the rural areas of San Juan and Mendoza. The traditional adobe block masonry walls are reinforced with foundations and plinth structure, which provide structural strength. A deficiency in this type of construction is that the adobe blocks deteriorate due to prolonged exposure to humidity.