Providing Safe Shelter

Following my earlier entry about the Nepal Earthquake, I ran across a number of great building ideas that should be more widely known and implemented.  Billions of lives all over the world depend on safe places to live that are resistant to earthquake damage, both to prevent injury and to provide continued shelter following an event.  A great article atNationalGeographic.com following the Nepal earthquake of 2015 cites two important rules for building these houses:

·         Keep it Simple

·         Keep it Local

Engineer Marcial Blondet of the Catholic University of Peru, in Lima is quoted as saying, “The devastation in Haiti wouldn’t happen in a developed country. Yet it needn't happen anywhere. Cheap solutions exist."  For example, the article includes this wonderful graphic showing simple techniques for using locally-sourced materials to create safe houses (descriptive text quoted from the article as well):

Pakistan

·         Light walls and gables

·         Lightweight structures are subject to smaller forces and are less likely to fall when the ground shakes.

·         Quake-resistant houses are being built in Pak­istan—of straw. The compressed bales are held together by nylon netting and sandwiched between layers of plaster.

Haiti

·         Light roofs

·         In Haiti heavy concrete roofs collapsed on many homes; in general, metal roofs on wooden trusses are more resilient.

·         Small windows

·         Small, regularly spaced openings create fewer weak spots in walls. But the bigger problem in Haiti was that walls were not properly reinforced.

Peru

·         Reinforced walls

·         The reinforcing rods need not be made of metal. Natural materials such as eucalyptus or bamboo work well too.

·         In Peru, the walls of some adobe houses have been retrofitted with a plastic mesh to prevent collapse.

Indonesia

·         Confined masonry

·         In Indonesia and elsewhere, brick walls can be framed and connected to the roof by corner columns and a crown beam of reinforced concrete. In a quake the structure moves as a unit. Tires filled with stones or sand and fastened between floor and foundation can serve as cheap ground-motion absorbers for many types of building.

The article includes another sobering quote by Blondet: “In Nepal, Haiti, Peru and elsewhere, risk is more abundant than the money or time needed to shore up dangerous buildings.  There are many millions of houses around the world that will collapse in the next earthquake."

Good Advice

Two experts--Maggie Stephenson, a United National reconstruction expert, and Bijay Krishna Upadhyay, of the National Society for Earthquake Technology in Nepal--offered a number of key points in an article in the New York Times.  They included:

    1. Build to last. It helps improve structural integrity.

    2. Choose the ground (and I would add location) wisely.

    3. Plan ahead, and plan conservatively.

    4. Check the quality of materials.

    5. Anchor the building well.

    6. Tie the building together.

    7. Columns must be secured.

    8. Avoid top-heaviness.

    9. Keep water away from the foundation.

Example: Build-Up Nepal

Buildup Nepal is a Not-for-profit company dedicated to rebuilding after the earthquake and fighting rural poverty. It was founded by a group of organisations, professionals and foreign experts with long experience in engineering, social business, management and rural development.

Build up Nepal works as an implementation partner for organisations that wants to rebuild and develop their villages, but do not have the construction and rebuilding expertise. We also run our own projects in different villages where we have been active from before.

Techniques/Ideas

Compressed Stabilized Earth Bricks (CSEB).  Most of the villagers in Nepal dream about living in a house of brick and concrete. But this is very expensive and not feasible in remote villages. With Earth Bricks this dream becomes a possibility. Earth bricks or Mud blocks is a perfect building material for villages in Nepal. It is made from soil, sand and cement and can be produced with a machine that runs without electricity. Compressed Earth Bricks (or soil blocks) is an old technique well suited for seismic sensitive areas. The blocks are made by Soil, Sand and stabilized with 8-10 % of cement.

Building permanent with Bamboo.  Bamboo is a strong and local material that can withstand both earthquakes and heavy weather. The Bamboo is treated to ensure a long life for permanent buildings. A 4″ thick panel is made with bamboo on both sides and plaster of either mud or cement to cover the walls. This creates an insulated panel making the houses very pleasant in both summer and winter. The bamboo panels can be manufactured locally in the village creating local jobs, cheap houses and opportunities for small business.

Reinforced stone with GI wire.  In very remote villages in the Himalayas transporting foreign materials is difficult and expensive. We are working with stone masonry buildings reinforced with galvanized iron wire. This technology makes it possible to reinforce stone building even in very remote locations at a low cost.