Appropriate Technology for Disaster Resistant and Post-Disaster Shelters
The greatest costs of rebuilding after the disasters goes to the infrastructure and human shelter.The need is ever more urgent to build self-help, emergency shelters which can become sustainable, permanent structures and are more resistant to more disasters.
An EcoShell is a concrete, thin-shell dome whose construction process includes a relatively new technique called Airforming.This technique uses an Airform that is made of a high-strength, high-tech fabric.
When inflated, the Airform, looking like a semi-rigid balloon, creates the EcoShell’s dome shape.In industrialized nations, particularly those with temperate or cold climates, such as the United States, Canada and Great Britain, the uninsulated EcoShell makes an ideal garage, small warehouse, grain storage, shed or workshop.But in the developing world, most of which has a tropical or equatorial climate, the EcoShell can provide permanent, secure, easily maintained and — most importantly — affordable housing.
Uses of Eco-Shells
- The typical mud hut offers very little protection or stability in that type of climate.
- Also, the excessive moisture in the huts causes an increased supply of bugs, snakes, disease and sickness.
- A Monolithic EcoShell, however, offers hurricane protection and keeps residents dry during the wet seasons.
- Monolithic domes can withstand earthquakes and winds of up to 300kmh.
- The Eco-Shell provides protection from hurricanes and infestation.
- A standard mud hut measures 160 sft.
- With an EcoShell, the concrete is applied to the exterior of an inflated airform.
- The airform is removed after the concrete has set.
- The Airform has been removed from the interior and workers get ready to apply another layer of concrete on the inside.
Earth bag- shelters
The earth bag houses of Nader Khalili, a Persian architect are cheap, environmentally friendly, earthquake resistant, flood resistant, fire-resistant and hurricane resistant. The basic construction technique involves filling sandbags with earth and laying them in circular courses that are corbelled near the top to form a dome. Barbed wire laid between courses prevents the sandbags from shifting and provides earthquake resistance.
The addition of barbed wire to the compression structures creates earthquake resistance; the aerodynamic form resists hurricanes; the use of sandbags aids flood resistance; and the earth itself provides insulation and fireproofing. The sustainability of this approach is further strengthened because the construction of the sandbag shelters does not require external intervention but can be built by the occupants themselves with minimal training. The system is also highly flexible: the scale of structures and arrangement of clusters can be varied and applied to different ecosystems to produce settlements that are suitable for different numbers of individuals or groups with differing social needs. Due to their strength, the shelters can also be made into permanent housing, transforming the outcome of natural disasters into new opportunities.The sustainability of this approach is further strengthened because the construction of the sandbag shelters does not require external intervention but can be built by the occupants themselves with minimal training.The system is also highly flexible: the scale of structures and arrangement of clusters can be varied and applied to different ecosystems to produce settlements that are suitable for different numbers of individuals or groups with differing social needs. Due to their strength, the shelters can also be made into permanent housing, transforming the outcome of natural disasters into new opportunities.
Paper Log houses
Paper tubes, which are erected in galvanized iron channels and held firmly in place by plaster of Paris, are used for the walls of the 3 by 4.8 metre, water-resistant structure.The floor is made of mud mixed with cow-dung, and locally available bamboo is used for the vault and roof. Criteria for the houses include the use of inexpensive and recyclable materials, simple construction methods, and satisfactory insulation properties.The paper structures at Bhuj can last upto six years.The villagers have began to adorn the cardboard structures with mirror-work, embroidery and rangoli. The 34-ply cardboard cylinder is the basic building block of the houses. The walls of the hollow tube act as insulators too.