DHAJJI DEWARI – Earthquake resistant construction system in Jammu and Kashmir, May - 2016 

Dhajji Dewari system - a valid construction in seismic area got its recognition after Kashmir earthquake in 2005. Due to its resemblance in the appearance to quilt patchwork of Persian weavers it is called as “Dhajji”. It is quite prevalent in the earthquake prone areas of Jammu and Kashmir. Significant earthquake resistance, cost effective, use of indigenous available resources and skill, swift in construction process makes it a selective choice for earthquake disaster re-inhabitation. It is also referred in the Indian Standard Codes as brick nogged timber frame construction. It has been in practice for more than 200 years. Similar forms of construction with some minor variations are found in various parts of the world.

Dhajji most commonly consists of a braced timber frame in different patterns. The spaces left between the bracing and/or frames is filled with a thin wall of stone or brick masonry traditionally laid into mud mortar, so as to create a patchwork of small size masonry panels. Completed walls are plastered in mud mortar. Dhajji buildings are typically 1-4 storeys tall and the roof may be a flat timber and mud roof, or a pitched roof with timber/metal sheeting.

The earthquake resistance of a dhajji building is developed in the following ways.

  • The mortar, masonry infill panels quickly crack in-plane thereby absorbing seismic energy through friction against the timber framing, and between the cracks in the fill material. Thus, distributing the earthquake energy evenly.
  • The timber frame and closely spaced bracing, which essentially remains elastic, prevents large cracks from propagating through the infill walls. Thus, the possibility of out-of-plane collapse of masonry panels is reduced considerably.
  • The masonry walls are kept relatively thin. This helps to reduce the mass of the building and therefore the inertial forces that must be resisted during an earthquake.

These structures are environmental friendly and traditionally would not have incorporated any toxic products in their construction, apart from the natural fungal and insect resistant chemicals in the timber itself.

During earthquake, houses made-up of Dhajji technology proved to be more resilient and suffered minimal damage compared to modern buildings made up of reinforced concrete.

 

Source:

https://www.unisdr.org/files/3646_IndigenousKnowledgeDRR.pdf

http://www.world-housing.net/WHEReports/wh100164.pdf

http://www.world-housing.net/asia/india/report-146-dhajji-dewari

https://www.scribd.com/doc/104690565/A-Paper-on-Dhajji-Wall