Multi Hazard Resistant Shelter

This multi hazard resistant shelter has not been built and it will never be built. But its design has been granted the first prize of a national competition in 2006 by Gandhigram rural University. Nevertheless, this concept is presented here to show how such a project can be conceived in a holistic way and can fulfill also the development of a community in normal times.

Natural disasters are an increasing threat worldwide. Disaster preparedness is essential to prevent too many losses of lives and infrastructure. Natural catastrophes, despite their increasing frequency worldwide, are limited to short periods of time. Therefore this shelter which can accommodate 200 families (~1000 people) during a natural disaster is more than a shelter to protect people during this kind of catastrophes. It is also planned as a community asset during peaceful times. It aims to be a tool for the village development.

Before a cyclone or tsunami strikes, people could take refuge in this disaster shelter. Many doors on the ground floor and large staircases and a ramp are organised for an easy access to the various floors. After an earthquake, people would find there a safe place with appropriate health care and the best possible living conditions.

Once a catastrophe strikes, people would be able to live there for at least a week or ten days in a complete autonomy. This would allow rescue operation to be organised. Everything is prepared and organised in order to give appropriate living conditions, not only during this time, but also for a longer period of time till the rehabilitation starts. Thus people could stay in this disaster shelter even for a few months after the catastrophe.

 Disaster times
Particularly in the stressful context of a natural disaster, it is essential that a family should identify a space and a facility as its own. Therefore, this shelter is planned to offer these facilities:
•    Decent places to sleep, to recreate and to live with certain privacy for every family.
    Each family (of about 5 people) has about 10 m2 to sleep and organise their living space.
    Moveable and light partition panels are stored in a few storerooms, so as to create separations between families living in the same room.
    The number of families per room is most of the time limited to 5 in a room of 50 m2: The various rooms would be converted into dormitories. Only 3 large halls can accommodate 20 families each.
•    Proper sanitation facilities for such a large number of people with an appropriate wastewater treatment.
    Each family is given a toilet, with a shower head inside, only for their own use. It is located near their room.
    Common showers and wash basins for 5 people at once are also offered in the toilet block.
•    Medical and even surgical facilities for injured people. Psychological trauma would also be dealt with.
•    Large food storages and restoration facilities to allow the preparation of 3 meals a day for everybody.
•    Independent water supply and large water storage for safe drinking water as well as water for the body.
•    Separate water supply for safe drinking water, treated by ultraviolet light.
•    Independent energy supply, both for the living quarters and the mini hospital.
•    Recreation facilities especially for children.
•    School facilities till the time that the rehabilitation starts.
•    Communication centre to keep in touch.
•    Space for burial and cremation grounds.
•    Storage space for the equipment needed (mats, mattresses, bed sheets, etc.)

Peaceful times
In peaceful times, this shelter is planned to offer these facilities to the community:
•    School with restoration for all ages:
    Crèche, kindergarten, primary and secondary school, and craft apprenticeship
•    Community centre
    Panchayat office, Disaster management cell, Union office
    Library, Knowledge Resource Centre, meeting rooms
    IT, Browsing and Communication Centre
    Cooperative Bank, Telephone exchange, Women Training Centre
    Multipurpose hall, Canteen with large food storage
•    Market with 28 stalls and a large hall
•    Mini hospital with basic surgical facilities
    Consultation and dressing rooms, normal care ward
    Sterile operation theatre, sterile care ward, X ray room and laboratory
    A ramp to access the upper floor for wheel chairs and beds
•    Burial and cremation grounds would also be used in normal times by the community.

Market at dusk

School Community street at night

This disaster shelter is planned as a community asset and it comprises of a School, a Community Centre, a Mini Hospital and a Market. Buildings have been designed according to the Indian standards for earthquakes resistance, and with the technology of reinforced masonry with hollow interlocking compressed stabilised earth blocks developed by the Auroville Earth Institute.

The proximity from the sea requires some precautions and particular site requirements. The disaster shelter starts at 200 m from the seashore and ends at about 380 m from it. The precondition for the site selection is that the original ground level is at least 5 m above mean sea level. The ground level around the shelter would be raised by about 85cm to have easy access for everybody. Thus the heights of the buildings would be as such :
  - Ground floor level : ~ 6.2 m above sea level
  - First floor level : ~ 10.4 m above sea level
  - Roof level : ~ 14.5 m above sea level
  - Storeroom roof level  : ~ 14.6 m above sea level
Buildings are conceived to resist earthquakes, cyclones or the waves of tsunamis but also to allow a normal usage in peaceful days, which will be mostly the case all along the years. Buildings are organised in such a way that if waves come, the ground floor could be flooded by waves higher than 6.2 m. The first floor level is about 10.4 m high from the mean sea level in order to be safe from most of waves. All roofs are accessible and they would be the safest as they are around 14.5 m above sea level. At this level are placed all bedding items. There is a total of about 3,304 m2 of accessible roofs.

All buildings are designed to have natural cross ventilation and natural lighting. Galleries are surrounding all the rooms, in order to protect from sun and rainwater. The first floors of all buildings are accessible from each other, by the outside staircase of the Community Centre, the ramp of the Mini Hospital and a bridge.

The main buildings are protected by the market which is placed at 45° from the sea front. It is meant to act like the prow of a ship, in order to break the strength of waves. Its shape also aims to send the intensity of the flow around the main buildings of the disaster shelter.

A dense grove is planted in front of the market and the entire village. It starts about 100 m from the sea front. Its thickness varies from 120 m to 200 m and stretches on about 1 Km long, so as to protect also the village. More than 100 indigenous species can grow so close to the sea and on sand dunes. This grove aims to break further down the velocity and intensity of the waves.

Wave-pressure - Plan

Wave-pressure - Section

It can welcome children from crèche, kindergarten, classes from 1st to 10th standards and crafts apprenticeship. Classrooms are 50.4 m2 to accommodate about 30 children. It offers food for all students, and a multipurpose hall for the community. The food storage, kitchen and dining hall are on the ground floor that can be easily used during normal times by the students and even by the community.

It has a few storerooms specially meant to store items to be used during a disaster. These storerooms would be emptied when needed and whatever is in the classrooms would be put in instead. Tables and chairs of the classrooms are foreseen to be folding, so as to take less volume in the storerooms during the time of a disaster. All beddings (mats, mattresses, pillows and bed sheets) are placed on the roof (14.6 m above sea level), so as to be the safest in the case of tsunami. Being on the roof, it would be easy to aerate them and put them under sun once in a while.

All rainwater falling on the roof is harvested into two underground tanks of 414 m3 each, which are located under the open courtyards. The energy supply is hybrid: solar powered but with inverters to run on 220 V, and current from the grid. A space for the batteries of the solar system is organised in one of the storerooms on the roof. The floor is over reinforced to bear the load of the batteries.

This centre is a multipurpose building that the village can use for its own welfare. The community hall on the ground floor can be used as a theatre, a marriage hall or meeting hall for large assemblies.

On the first floor is a space which is foreseen as a canteen to be used also during marriages in normal times. This space is meant to be the main dinning hall during disaster time. There are large food storages on the same level, so as have a stock of food which would be used just after a disaster. These storerooms can be accessed to by the outside staircase, as well as the ramp coming from the Mini Hospital and the bridge. The Community Centre presents the same details as the school, for the storerooms, rainwater harvesting, water system, energy supply, etc.

This mini hospital is meant to provide healthcare to a larger area than this particular village. It has facilities to take care of common patients with small ailments as well as an operation theatre especially for the time of disasters. This facility could also be used in normal times to take care of people locally.

The first floor is accessible via a ramp for disabled people in wheel chairs or beds. This ramp links also the gallery of the School. The Mini Hospital presents the same details as the school, for the rainwater harvesting, water system, energy supply, etc. The battery bank is located in the room of the air conditioning unit.

This space is placed close to the school in order to create a street pattern for commercial activities. The street is large enough to allow a heavy vehicle to turn around the school. Its walls are over reinforced and all roofs are done with reinforced concrete slabs, so as to act as diaphragm and to stiffen the whole structure. This building is meant to break the strength of a wave and diverse the intensity of the flow around the main buildings.

Ground Floor
2,415.1 Ground Floor 1,553.7 Ground Floor 696.8    
First Floor 2,416.6 First Floor 1,553.7 First Floor 626.6    
Roof 205.5 Roof 201.6        
Total area school 5,037.2 Total area community centre 3,309.0 Total area mini hospital 1,323.4 Total area market (Ground floor) 494.2

A space outside the village is foreseen for that. It is located far away from the disaster shelter and the bore well.

The wastewater treatment is a baffle reactor system with a capacity of about 250 m3. It is planned for 1000 people, consuming about 40 litres per day. This system collects grey and black water which passes through the various chambers in 6 days.

The system has been designed to function with or without EM (Effective Micro Organisms). EM has been researched and developed since many years by scientists in Japan and worldwide. It consists of a “mother liquid”, which can be diluted, composed of various bacteria working in different conditions, from anaerobic to aerobic ones. EM brings oxygen to water and progressively transform the anaerobic condition to aerobic one. It is a much more effective treatment than the usual anaerobic systems. Using EM means bringing awareness to villagers about usage of water, wastewater treatment, etc. EM have also much more usage than just treating wastewater and it can be part of the village awareness and development.

After 6 days of retention, wastewater passes through a planted filter of 40 m long for a complete oxygenation. This planted filter is normally not required with EM, but it has been added in case EM cannot be used for various reasons. After passing through the planted filter, water does not smell and goes through a polishing pond with floating plants such as water jacinth. The overflow of treated water can be harvested for gardens or send to the sea.

This system is also meant to be used by the village in normal times. During a natural catastrophe, the system would be connected only to the various buildings of the disaster shelter.

During disaster times, water supply is a major difficulty. The disaster shelter has been organised to have constantly safe water. Water supply comes from two sources: a bore well and rainwater harvesting.

Bore well
It would supply the entire village in normal times. It is located almost 1 Km for the shore line, so as to avoid sea water intrusion via the water table in normal times. To avoid sea water intrusion during a tsunami, the top of the casing with the delivery pipe will be sealed. It is planned to be 100 m deep with PVC casing.

Water could be pumped with 2 pumps: a submersible hybrid pump (solar and grid currents) or an electrical pump of 7.5 HP for 8 m3 per hour. These two pumps are installed so that one would be the back up of the other one or they could pump alternately so as to have 24 hours of pumping. The Grundfos SQ Flex submersible hybrid pump can run with various voltages, either with DC current from solar panels, or AC current from the grid or a generator. This solar pump would require 24 solar panels of 70 Wp. This pump has a pumping capacity of 15 m3 per day (of 8h) with solar energy or 2 m3 per hour with 220V AC. Therefore, the well could provide daily about 45 m3 with only the solar pump (pumping 24 h./day) or about 100 m3 with only the 7.5 HP pump (pumping half day only).
Rainwater harvesting
All rainwater falling on the roofs is harvested into underground tanks. The latter are located below the open courtyards of the buildings. Rainwater is filtered through gravel/sand filters before entering the tank. This water would also be used by the entire village in normal times. It is obvious that these underground tanks would overflow, as they can store about a fifth of the total annual rainfall. This overflow water will be send away to the sea through a 12” PVC pipe. This amount of rainwater can be stored in these tanks:
- School
- Community Centre
- Mini Hospital
: 2 underground water tanks of 414 m3 each
: 1 underground water tanks of 414 m3
: 1 underground water tanks of 80 m3
 Total capacity  : 1,322 m3 for 5,285 m2 of roofs
Note that sea water could enter the underground tanks in the case of a tsunami, especially via the overflow pipe. Elaborating a system to avoid sea water intrusion for this tank would become to complicate and at the end might not work if maintenance is not done properly. The idea is that sea water could enter these underground tanks and be pumped out later on, once the wave went back. The tank would be refilled directly with bore well water.

Overhead tanks, drinking water and water pumping
Bore well water is directly sent into the overhead tanks. It is pumped first in the drinking water tank and then by overflow into the tank for regular use such as showers, toilets and washing. The School and the Community Centre have 3 overhead tanks of 33 m3 each, which are placed at top of the staircase tower. Drinking water is stored in a separate tank of 6 m3, also on top of the staircase tower. This drinking water tank is located within the tank for regular water, but it is completely independent and it is higher, in order to fill the tank for regular use by gravity.

Bore well water is normally safe and it goes directly into the drinking water tank. But in case of any problem of water quality, the plumbing network would allow this water to pass through an ultraviolet light and filtering system to sterilise it.

Water is pumped from the underground water tank to the overhead tanks with another Grundfos SQ Flex submersible pump. In fact there are two pumps of this type for each underground tank, as backups. This water can be pumped either to the tank for regular use or to the drinking water tank, after passing through an ultraviolet light and filtering system to sterilise it. The overflow from the overhead tanks goes into the underground one.

All buildings have separate water supplies to the building. Drinking water is supplied only to the kitchen, the dining hall, the multipurpose hall and various points in the galleries. Note that it has been preferred to use solar submersible pumps for this underground tanks as they are more efficient than centrifugal surface solar pumps. Their output is higher and they require less solar panel.
Each courtyard in the School and the Community Centre has also a hand pump that people could use for washing or bathing at the time of disaster.

During disaster times, energy supply is also a major difficulty. The disaster shelter has been organised to have constantly electrical supply. It comes in 220 V. AC, from three sources: the grid, solar and / or a generator. Note that they are no particular details to mention about the electrical supply from the grid.

All Buildings are all supplied with 220 V. AC current and they are all equipped with low consumption bulbs. An average of two bulbs is foreseen for each room in the various buildings. Solar panels will be fixed on the roofs and mounted on stainless steel frames bolted in the diaphragm slab, so as to be cyclone safe. Their number will vary according to the various buildings and purposes.

The proposed solar lighting battery backup systems will be able to run for 5 hours during the night. Note that the current is inverted from 12 V. DC into 220 V. AC, as the distance of transportation is too long. This would save a lot of energy as well allow to using any normal electrical device.

The maintenance-free battery bank would be charged from solar power under normal circumstances. In case of low sun radiation, batteries would be charged from the grid or a generator.

The solar energy system is as such:
 School - Light: 150 CFL bulbs, 11W each – 48 solar panels (70 Wp) – 2.5 KVA /48 V. pure sine wave inverter – 650 Ah/48 V. Maintenance free battery bank
- Water pumping: 2 Nos. Grundfos SQ Flex hybrid submersible pump – 6 solar panels (70 Wp)

Community Centre - Light: 80 CFL bulbs, 11W each – 24 solar panels (70 Wp) – 2.5 KVA /48 V. pure sine wave inverter – 350 Ah/48 V. Maintenance free battery bank
- Water pumping: 2 Nos. Grundfos SQ Flex hybrid submersible pump – 6 solar panels (70 Wp)

 Mini hospital - Light: 50 CFL bulbs, 11W each – 12 solar panels (70 Wp) – 1.4 KVA /48 V. pure sine wave inverter – 400 Ah/48 V. Maintenance free battery bank
- Water pumping: 2 Nos. Grundfos SQ Flex hybrid submersible pump – 6 solar panels (70 Wp)

About 10 solar street lights would be placed near the main entrances of the buildings and near the market. These systems have three days autonomy without sun and they can operate from dawn to dusk: Light with 11 watts CFL – Maintenance free battery Amco 65 A/12 V. – 60 Watts BHEL Solar Module – 3" Post 5m High

The Mini Hospital has solar light and a 62.5 KVA diesel generator as a backup for power cuts in normal time and at the time of a disaster. This generator could also supply power in normal time for the village.

Accommodating about 1000 people requires a large building which can become fragile, especially in the case of an earthquake. This is one of the reasons why the disaster shelter has been split in several buildings.

Each building is quite large and it is needed to divide some of them in building blocks.

Separation gaps and building blocks

Separation gap – Plan
According to the Indian Standards, buildings have been separated by separation gaps. These ones are larger than the usual requirements so as to follow the pattern of the blocks and to have dimensions following the bond pattern.

The blocks of the School and the Community Centre are separated by 7 cm, as well as the ramp of the Mini Hospital and the bridge linking the School and the Community Centre. Precaution has been taken to cover these gaps in such a way that it would not disturb the collision during quakes. The staircase towers of the School and the Community Centre are separated by 12.5 cm. This would allow these towers to swing without touching the main building.

Separation gap – Section

Foundations and plinth
Buildings are resting on trench foundations at 1.3 m below the original ground level. They are made of RCC in M20 concrete and have a size of 80 x 30 cm. The plinth beam of the galleries is 1 m above the original level and the rooms are at 1.2 m above it.

They are built with Hollow Interlocking Compressed Stabilised Earth Blocks (HI CSEB). They are reinforced near openings, corners and wall junctions with vertical ties of ø10 TS in M20 concrete. Spacing of these bars varies with the location of the openings, but their average spacing is about 1.7 m.

The number of vertical ties varies sometimes from ground floor to first floor, according to the pattern of the walls and openings. Nevertheless, these bars are most of the time continuous from the foundation beam till the parapet wall. The various buildings are reinforced with these bars:

- Ground floor 1359 vertical ties
School - First floor 1348 vertical ties
- Third floor (roof level) 136 vertical ties
- Ground floor 894 vertical ties
Community Centre - First floor 894 vertical ties
Third floor (roof level) 894 vertical ties
Mini hospital - Ground floor 894 vertical ties
- First floor 894 vertical ties
Market - Ground floor 894 vertical ties

Several ring beams tie horizontally the buildings. There is an average of 11 ring beams in about 11.4 m height (from the foundation to the parapet level).

They are made with composite materials: U CSEB and RCC in M20 concrete, with 2 ø 10 TS bars and stirrups spaced at 25 c/c.

The staircase of the Mini Hospital, which supports the water tank, is over reinforced with 33 vertical ties and 12 rings beams. This stair case cannot be separated by a gap from the building. Therefore, in order to make it more stable, it is linked on the other 3 sides, of two levels by heavy concrete beams to the building.

Mini hospital – Reinforcement of the first floor staircase
Typical section

RCC Staircases
The structure of the staircases of the School and Community Centre supports the water tanks. They are built with a heavy reinforced concrete frame resting on a foundation slab, 40 cm thick and 3.4 m below the original ground level. The staircases are also with RCC.

Water tanks
All water tanks are made of RCC in M20 concrete and waterproof with cement sand plaster. There are 2 tanks above each staircase and they are anchored in the concrete frame of the staircase

The ramp accessing the first floor of the Mini Hospital/School and the bridge linking the School and the Community Centre is built with a reinforced concrete frame. The ramp itself is a concrete slab of 15 cm thickness. It has a slope of only 3.6%, so as to allow wheel chairs and rolling beds to access it. In front of the ramp of the Mini Hospital, there is a large space which can be used as a plaza in normal times and as a helipad in disaster times.

Lintels and arches
Composite lintels (U shape CSEB and RCC) are spanning the inside openings. Arches are used to span the openings of the galleries. Segmental arches have been chosen for they have a good stability under earthquakes. It has been seen in Gujarat that arches could withstand very well the 2001 earthquake of Kutch.

Floors and roofs with ferrocement channels
Ferrocement is an alternative to reinforced concrete. Ferrocement is a versatile material which can be used for roofs, as channels, for doors, shutters, overhangs and many building components. It can replace in many cases reinforced concrete slabs. The cement sand mortar covers one or several coats of chicken mesh. Ferrocement channels are reinforced in their tensile area with steel bars.

A limitation of ferrocement channels is that each piece is independent from each other and the roof cannot act as a diaphragm to stiffen the walls. This has been corrected in the case of the disaster shelter. Channels are also anchored on the walls but they are also tied together so as to act as a diaphragm:
Channels are laid in between 2 ring beams. At the first floor they are tied together with ø 10 TS bars @ ~105 cm spacing. On the roof a RCC slab of 6 cm thick links all channels with a mat of ø 10 TS bars @ 25 c/c.

Section on floor with ferrocement channels

Section on roof with ferrocement channels
Floors and roofs with Vaults
Segmental vaults have been chosen to give a certain character to the buildings. High vaults are not really stable during an earthquake. The flatter the vault is, the more stable it is in the case of a disaster, as long as walls can bear the amplification of the thrust. The segmental vaults of the disaster shelter have been dimensioned in order to get the line of thrust nearly centred in the vault thickness, which is the optimal case.

The quake would move this line of thrust alternately towards the intrados and the extrados. Nevertheless, the thickness of the vault is such so as to keep the line of thrust in the middle third of the vault, which is the condition of stability. As a precaution, a diaphragm / compressive RCC slab of 6 cm thickness is cast above and anchored in the springer beam.

With its proportion, this vault has an intense horizontal thrust of about 4,200 Kg/m. The latter is balanced by a springer beam with RCC in M20 concrete. The vaults in the rooms have truss rods every 1.5 m, which are made of stainless steel ø 32 mm. This gives a resistance 3 times more than the admissible stress.

Springer beams are anchored in a RCC portico in M20 concrete. This one acts as a rigid frame to support the vaults and to neutralize the horizontal thrust. These vaults would be built with plain compressed stabilised earth block and with the Free Spanning technique developed by the Auroville Earth Institute.

Section on vaults for floors or roofs

This disaster shelter is part of a disaster preparedness endeavour. Therefore, the facilities provided by these buildings should be known by the community and people should be trained to use it at its best.

Disasters, despite their increasing frequency worldwide, are limited to short periods of time. Therefore the probability that this building would be used because of a disaster is very low. It might be used for that purpose only for a few weeks or months per century. This means that the training imparted to a village team should be passed on from generation to generation.

An appropriate way to achieve this goal is that a routine is established for the use and maintenance of this asset. Once in a year could also be organised a general repetition for the entire village, like it is practiced in Japan. This kind of preparation should be undertaken with a lot of care, so as to avoid the development of a kind of fear or psychosis for the disaster. The disaster management cell, located in the Community Centre, would have an essential role in the disaster preparedness and not only for the management afterwards.

When these buildings would be used as disaster shelter, the various rooms of the buildings would be converted into dormitories and 204 families could be spread as such: 130 in the various rooms of the school and 74 in the various rooms of the community centre.

Note that the kitchen and the canteen would always be kept for this purpose. The entrance hall is converted as a dormitory, as there are many entrances to the building.
There are 80 toilets in the Community Centre.

The equipment needed during the time of a disaster (buckets, dishes, beddings, etc.) would be taken out of the storerooms and the furniture of the various rooms would be put in instead. Note that all buildings are meant to be used in normal times by the community, but the equipment foreseen for the time of a disaster should not be used by anybody. They should be maintained and kept only for these difficult times.

The shelter has been designed to take care of post-disaster conditions. But, then what happens to the shelter in the “non-disaster” times. Similar endeavours in the past for disaster shelters taught that a design meant for specific use becomes irrelevant for the normal day-to-day life of a community. They often become an empty and abandoned dead shell, which cannot even be used for their purpose in the time of a disaster.

On the contrary, the concept presented here proposes a perennial building; the provided facilities guarantee an integrated and appropriate usage over the years. To achieve this aim, the facilities must answer, first and foremost, the needs of a community in a particular context. Obviously, the shelter should easily be transformed in a very short time during the time of emergency.

On one hand, the shelter is aimed to satisfy the needs and living patterns of villagers and on the other hand to stimulates an integrated and sustainable development, a collective endeavour where education for everyone, women empowerment, healthcare, local management skills would be promoted.

Apart from being disaster resistant and climatically comfortable, the shelter has been designed to integrate identity and lifestyle of Indian villages. The facilities, like the hospital, market and street pattern propose a semi-urban area, inviting people to stay in their village, love it and develop it.

Spontaneous everyday usage of these spaces would give a direction to allocating suitable functions at the suitable place when a disaster actually strikes.

Lay out of the disaster resistant shelter

Ground floor plan of the school

First floor plan of the school

Roof plan of the school

Sections of the school

Elevations of the school

Water supply principles

Ground floor plan of the Community centre

First floor plan of the Community centre

Roof plan of the Community centre

Sections of the Community centre

Ground floor plan of the Mini hospital

First floor plan of the Mini hospital

Elevations of the Mini hospital

Layout of the market

Plan of the wastewater system
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