EARTH QUAKE RESISTANT
An earthquake resistant building cannot withstand the highest level on Richter Scales. What it needs to allow, however, is time for its occupants to evacuate even if the building itself is subsequently altered and weakened.
An earthquake resistant structure has reinforced structural elements to guarantee a certain resistance to unusually high-level pressures.
The foundations are a crucial part of the construction process. They might not be visible on the surface but they are what allows the building to anchor itself to the ground and limit the risk of it toppling over. They allow vertical quoins and dig down so that the building takes support on where the ground is even. Unfortunately, in Nepal, they are often neglected or non-existent.
Because we often intervene in isolated areas, we decided to use local materials and native building techniques. For those reasons, walls made of dressed stone are often present in our projects.
In addition to the stone header and the corner stones, vertical and horizontal chainings are essential.
Made out of wood or stone, there are 4 horizontal chainings: the bottom wall plate, the sill, the lintel and the top wall plate. This technique divides the wall into sections and the building is arched. These different sections connect up to all the vertical chainings.
When doing wood frame work, a technique usually employed for building a top floor or an attic, the walls are filled in with cob.
By diversifying our construction methods, we can both reduce the cost and time it takes to build. In spite of this, the calculations relating to the building’s structure are important and the making of cob must be meticulous in order to guarantee its long life.
To insure a good resistance in case of an earthquake, bracing the roof is essential and yet it’s often omitted. While a careful study of the structural integrity is important, the choice of the roofing material is also crucial. In Nepal, due to the repeated earthquakes, local populations have lost faith in the use of slate, considered too heavy and impractical. Yet this material, available in great quantities after extraction, offers many advantages. Among our other actions, we try to reconcile the inhabitants with these kinds of materials by teaching them accessible construction techniques.