Scaffolding in Mumbai

The technique chosen is bamboo simply tied, not only because it is the most efficient and the cheapest solution for bamboo structures, but also because it is a local technique and it is so simple that it can be taught even to kids. Bamboo is everywhere used: scaffolding in the cities, huts in the countryside, stands in markets. In many countries any shopkeeper, any kid helper is able to tie beams and create a simple structure. The aim is to teach people how to build their homes and how to substitute or reinforce the damaged beams. It is important to remember that any shantytown is a small society, with internal government and unofficial rules. Even now people help each others to build their homes, and other people’s job is to fix that buildings. In the case of Shantitown it is just simpler and cheaper. Bamboo is called “vegetable steel” thanks to its mechanical property, but also “poor’s wood” for its low price and its use in the poorest situations. Besides its environmental impact is very low and its growing is fast. 

In order to better understand the behaviour of bamboo scaffolding structure, I did several studies in the city of Mumbai. The scientific observation of young kids who fast tie the bamboo beams with coconut fibres for hundred of metres has been very useful to create a model with Straus software as similar as possible to reality, and to understand the techniques of the construction site in poor contexts and the quick time of execution of that kind of frame. 

The bamboo scaffolding is composed by main vertical beams called “posts”, with a distance between them of not more than 3 meters. Between them there are the secondary vertical beams, called “standards”. The horizontal connections between these members are made with the “ledgers”, perpendicular to the building, there are the “transoms".

The technique of bamboo scaffolding is very ancient and, especially in Asia and universities are trying to extract precise data and values from a technology based on a thousand year experience. There are many different values on the resistance of bamboo cane depending on the kind of plant, the moisture content, its age, and many other characteristics that are very specific. For the choice of values a lot of considerations and comparisons between the different sources have been done. 

In Shantitown numbers should not be precise because the building is made by inexpert people and is settled in an informal context. So the analysis performed consists of a series of experiments on models with damaged beams in random positions. The goal has been to find out a model previously reinforced in its most fragile part, so that even with serious damages of the structure the main frame can not collapse. The way to find out the most delicate beams to be previously reinforced in this particular frame is by numerous random experiments on 3D models, each of those damaged in its structure in a random way. Besides, it will be taught very easily to people to recognize the serious damages that they must reinforce to keep the structure safe.

Structural Analysis

The purpose of the structural analysis of Shantitown modulus was to guarantee two of its main principles: the freedom of its composition and the issue of keeping its safety in time. The first point is essential because in a slum like in any other emergency situation people build the spaces they need, so they must be free to open a door for a house or a bigger opening for a shop. The second issue for the structural analysis is connected to a self building system that is built up and checked in time by people themselves.

As a starting point two analyses were performed: a reference model, named “Model 0” was created with Straus software. It is a model where the internal structure is totally closed, with no openings for doors or windows. This model has been analyzed with the loads to identify the critical points of the structure that collapse under the loads. Then those points have been reinforced with secondary beams and that is the basic Model 0 to which all the results of the next analysis will be referred to.

Then a huge series of 3D models have been created to find the safest solution for the structure. Each model starts with the frame of Model 0 reinforced to resist to the loads as previously calculated, then every model have been damaged in its structure, simulating the situation of broken beams or missing beams in random positions, such as the real situation in a slum could be. So the analysis started from the different positions and dimensions of openings to demonstrate that that choice does not have influence on the main structural stability; then the models started to be damaged in a few parts to control the behaviour of the single wall or portal; then the damaging interested the entire structure, always in a totally random way. All the results were useful to control the model and to obtain the final frame, reinforced in its weakest points, where demonstrated by the hundreds of random damaged models. In this way, this final structure is preventively reinforced to avoid its collapse even in case of multiple damages.

Do it yourself

Bamboo frame, simply tied as in Asian scaffolding system

Drums, concrete and bamboo as foundation

 

Strategies

Recycled material

A view on Dharavi: Koliwada

Koliwada inglobes the original first settlement of Dharavi: this area was a village of fishermen called Koli. Today it is difficult to recognize the original buildings and the Kolis people is only 6% of the population. 
This district is very famous for the gold worked in Tamil style. 

A view on Dharavi: Transit Camp

This district was born in 1985 from the PMGP (Prime Ministre's Grand Project) to improve the living condition of people in Dharavi. As the name says, it should have been a transit solution for people that the government moved to build new streets and buildings. In time, the "transit" word lost its meaning. 
It is an interesting district to study the abitative solutions that the government gave to people.

 

A view on Dharavi: 13 Compound

This is the "industrial" district of Dharavi. 
The main activity is recycling, mainly of plastic. It is the biggest industry of this kind in all India with more than 5.000 workers, payed about 40 Rupies a day for 11 working hours. This activity brings millions of Rupies to Mumbai.