BAMBOO RELIEF STRUCTURE

1. By - Sahil Singh
Lokesh Uchaniya
Anant Dayal
Bamboo Disaster Relief Structures

2. Introduction
Bamboo is one of the most sustainable building materials
on the planet and is termed as vegetable steel with a tensile
strength of 28000 per square inch and provide earthquake
resistant structures.
Facts About Bamboo
● Bamboo contains high levels of starch which
attracts insects.without proper treatment, bamboo
has a natural durability of less than 2 years.
● • Species like genus “dendrocalamus” and
“bambusa” have the best properties for structural
applications.
● • One of the fastest growing plants on earth.its
growth rate ranges from 30 cm to 1m in 24 hours.
● • 1450 species are found in diverse climates across
the world.
● Light, strong and versatile
● Environment friendly
● Accessible to the poor
● Self renewing resource
● Fast growing
● Highly productive
● Earthquake resistance
Advantages of Bamboo
The various advantages of bamboo are mentioned below:

3. How to protect bamboo
Soaking:
A method commonly used in India is to soak bamboo
for ninety days in water. Then set to dry in a sunny
area for two weeks
Air Drying
Cut the bamboo leaving the branches and leaves still
attached. Store the bamboo upright in the sun for
two weeks. Then continue drying in a cool dry place
out of direct sunlight,cross your fingers and hope for
the best. Depending on the area, watch for molding.
Aburanuki:
The Japanese method of drying used by the Shaku
hachi or flute makers of Japan.
Soaking
Air Drying

4. Main Properties Of Bamboo
As discussed before that Bamboo is a viable alternative for steel, concrete
and masonry, it is so because of its properties which are clearly mention
below
TENSILE STRENGTH
Bamboo is able to resist more tension than compression. The fibers of
bamboo run axially are of highly elastic vascular bundle that has a high
tensile strength. The tensile strength of these fibers is higher than that of
steel, but it’s not possible to
COMPRESSIVE STRENGTH
Compared to the bigger tubes, slimmer ones have got, in relation to their
cross-section, a higher compressive strength value. The slimmer tubes
possess better material properties due to the fact that bigger tubes have
got a minor part of the outer skin, which is very resistant in tension
ELASTIC MODULUS
The accumulation of highly strong fibers in the outer parts of the tube wall
also work positive in connection with the elastic modulus like it does for
the tension, shear and bending strength. The higher the elastic modulus,
the higher is the quality of the bamboo
ANISOTROPIC PROPERTIES
Bamboo is an anisotropic material. Properties in the longitudinal direction
are completely different from those in the transversal direction. There are
cellulose fibers in the longitudinal direction, which is strong and stiff and in
the transverse direction there is lignin, which is soft and brittle.
FIRE RESISTANCE
The fire resistance is very good because of the high content of silicate
acid. Filled up with water, it can stand a temperature of 400° C while the
water cooks inside.

5. Major Uses of Bamboo in
Construction
Bamboo Trusses:
The bamboo has strength comparable to that of Teak and Sal. A frame is made
using bamboo rafters, purlins etc for fixing the roof
Bamboo Roofs Skeleton:
It consists of bamboo truss or rafters over which solid bamboo purlins are laid
and lashed to the rafter by means of G.I.wire. A mesh of halved bamboo is
made and is lashed to the purlins to cover the roof.
Bamboo walling/ceiling:
As the bamboo material is light in weight it is beneficial for earthquake prone
areas as its chances of falling are very less due to flexibility and even if it falls
it can be re-erected easily with less human and property loss with least
efforts and minimum cost. Bamboo walls can be constructed in different ways
like
Bamboo Doors and Windows:
Bamboo replace timber frames appropriate to function. mat shutters fixed to
bamboo frame bamboo board fixed to the frame which wall can be used as
door. Small framed to the top in the wall can serve as windows.
Bamboo Flooring
Bamboo can be used material due to its better wear and tear
resistance resilience properties. Whole culms act and the floor
covering is done using bamboo boards, mats etc by means of wire to
the frame.
Bamboo Trusses
Bamboo Roof
Bamboo wall/ceiling
Bamboo mat walls
Bamboo flooring

6. Bamboo As Disaster Relief Material
Dubbed the "fastest-growing plant on earth", bamboo provides structures that are durable,
cost-efficient and easy to construct and transport and could revolutionise the provision of
shelter for millions of people displaced by natural disasters and conflict, manufacturers say.
Due to plant’s strength and flexibility, bamboo houses can withstand earthquakes of up to 6
on Richter scale and if a building collapse it will case minimal injury due to its lightweight
and elastic properties unlike concrete structures.
Natural disasters such as cyclones, earthquakes, floods as well as civil war one of the
biggest challenges is providing shelter which are durable, cost effective and east to
construct and transport: BAMBOO fits the criteria, hence bamboo as a construction material
has a role to play in post-disaster rehabilitation
Not only in India, bamboo is well known for earthquakes resistant and landslide-proof
housing widely used in LatinAmerica, and more recently in China for rebuilding after the
Sichuan earthquake. Looking at its properties and wide range of uses, this plant has a far
more potential to benefit livelihoods in conflict and disaster- but today is not yet well-
known or specified as a material of choice for a number of useful applications.
EASY KNITTING OF JOINTS FOR POST-DISASTER SHELTER

7. Bamboo As Disaster Relief Material
● High residual strength to absorb shocks and impacts.
● Flexure coupled with its very low mass
makes it an idle material for making
buildings safe against disasters
● A bamboo house in Bhutan withstood an
earthquake that occurred at Sikkim
(epicenter) measuring 6.9 in September 2011
● Prototype house built with bamboo sheet
roofing and bamboo-reinforced withstood a
earthquake measuring 7.8 in Richter scale
survived without damage Costa Rica in 1991
● Bamboo used increasingly for
disaster-relief construction projects in
● Shelters for earthquake victims in Nepal,
● Temporary accommodation for Burmese refugees in Thailand,
● Flood-resistant housing in Vietnam
● High strength,
● low cost and
● wide availability.

8. Seismic Performance Of Bamboo Housing
Bamboo is used as a predominant structural member and bamboo
frame as a predominant structural system, during earthquakes.
Ikra type of construction,
Bahareque construction
Dhajji Dewari constructions
Since India has large areas falling in the zones of high seismicity,
bamboo can play a vital role in appropriate housing and
construction owing to its suitability and availability.
It is in this context that the bamboo housing technology developed
at IPIRTI in collaboration with Timber Research and Development
Association (TRADA),

9. Ikra Type Of Housing Technology
Traditional construction in Sikkim consists of mostly of typical bamboo houses,
known locally as “Assam-type housing” and also known as ‘Ikra’ wherein a weed called
Ikra is extensively used in the walls and the roof of the house.
Ikra type of housing technology consists of stone masonry walls up to 1m above the
plinth and the rest with wooden frame consisting of woven bamboo mat plastered
with cement or mud mortar. A typical Ikra type housing is shown in Plate
The roof generally consists of light-weight materials such as Galvanized Iron (GI)
sheets or thatch roof, supported by bamboo/wood trusses, which are laterally
connected to the parallel walls.
Steel angles and flats with bolts and nails are used to connect the Ikra wall to the
masonry foundation wall.
These types of houses, constructed on slopes, are susceptible to landslides or slope
failure and can be unsafe during strong earthquake ground motion as unequal
lengths of posts lead to unsymmetrical shaking. In plains, these buildings are
observed to perform the best. In the event of earthquakes, it was observed that no
injury was caused due to the falling of debris of Ikra walls.” They go on to state that
“reinforced concrete buildings were severely damaged, during the event.”

10. They also state that “the mud-dung wall plaster
becomes brittle during summer and requires
maintenance as it comes out during the rainy
season. If vertical posts are directly plugged into the
ground without foundation, the differential
settlement may lead to lateral sway of the house.
” They emphasize that, “light mass of walls and roofs,
good wall-to-wall connection, flexible connections
(bolting, nails, grooves, etc) between various wooden
elements at different levels will influence the
earthquake safety of the house.” Ikra houses may not
be suitable for construction of higher stories due to
possible amplification of ground motion along with
the height.

11. Bahareque Type Of Construction
Bahareque consists of timber vertical elements and horizontal timber,
cane or bamboo elements, with mud infill and finished with plaster.
Such systems are prevalent in quite a few countries. In El Salvador, the
first type of bahareque consisted of small tree branches bonded with clay.
Later dwellings were constructed by using a foundation of stones or clay
into which vertical wooden posts were inserted.
Horizontal rods were attached to the vertical posts and both structural
members formed the skeleton of the dwelling.
The body of the house was created using bamboo elements with mud infill
and covered with plaster . Wood frames covered by palm fronds
constituted the light roof system.
The framework can be made of wooden studs, wooden braces or wooden
grid with bamboo strips or barbed wire to provide better infill adhesion.
Mud, mud with pebbles or stones, and mud with tile pieces may constitute
the bahareque infill.
To cover the wall, a plaster made of lime or mud is employed. The roof is
made of wooden frames and clay tiles.
Rural construction of bamboo vernacular houses of Ecuador are made
almost exclusively with vegetable material, using bamboo poles for most of
the structure, for walls and floors, palm leaves or grass for the roof and,
where flooding is frequent, timber poles to raise the floor from the ground.
The esterilla of the walls is left uncovered.

12. Construction Technique
“The timber to be used must be treated and provided
with maintenance.”
“The foundation timber must be placed above the
stone masonry foundation with a least height of 0.3m
above the ground to protect them from the ground
moisture.”
“The spacing of the bamboo or wooden grid must be
less than 0.15 m.”
“The infill paste should contain vegetable fibers to
increase the strength.
The usage of barbed wire on the bahareque grid
gives more adherences to the infill paste.”
“The plaster cover is to be made of lime to protect
the walls from humidity and to provide a neat finish.”
Modern Bahareque building
Traditional Bahareque building

13. Dhajji Dewari Constructions
Dhajji is an old Parsi word used to describe patchwork quilts
and the same was applied to the traditional building technique
of the Kashmir region in India. Dhajji construction is made of
highly subdivided light timber frames with masonry infill.
In Dhajji, the energy distribution is through small panels, as
opposed to cases like big panels where the energy is highly
concentrated.
In this construction, there is friction between the mud mortar
and the bricks which dissipates the energy and hence helps in
reducing the earthquake forces.
The Dhajji Dewari style of construction emerged as a
time-tested earthquake resistant technique, indigenously
developed through lessons learnt from repeated earthquake
disasters over several generations, both in the rural and urban
setting of Kashmir which falls under seismic zone V.

14. Structural Analysis
A dhajji dewari house of the type now commonly being constructed in Pakistan
after the 2005 Kashmir earthquake was chosen for detailed nonlinear dynamic
time history analysis as shown in Figure 2.
The timber frame and the masonry blocks were modelled as solid elements with
contact surfaces between all members to account for frictional behaviour.
The light weight roof system was idealised as beam and shell elements. Nailed
connections were modelled as discrete elements with non-linear material
properties. The flexible mud mortar was not explicitly modelled.
The masonry infill was assumed to be incompressible and the timber was
modelled as an elastic material. The roof did not include horizontal diaphragm
bracing as typically this is not a design feature of these buildings.

17. Full Building Static Pushover Analysis
Two quasi-static nonlinear pushover tests have been conducted in the long and short directions for the entire
building with nails.
In each case, the pushover was carried out by pushing one end of the top ring beam at a constant rate horizontally
and at the same time recording the foundation forces to generate characteristic force-displacement curves for the
building as shown in Figure 10.
The buildings were displaced by over 1.0m over the building height at a constant rate until they collapsed, seen by
the drop off in the lateral resistance of the building, as shown in Figure 10.
The imposed lateral drift level is very high and is more than would be expected from the largest earthquake
specified in the Uniform Building Code 1997 (UBC97, Zone 4 peak ground displacement at a building period of 1
second is approximately 200mm)

18. Indian Pavilion At Expo 2010 - Shanghai
● pavilion at Expo 2010 in Shanghai.
● Pavilion world’s largest bamboo dome-- about 34 m (112 ft) in
diameter, with bamboo beams/members overlaid with a
ferro-concrete slab, waterproofing, copper plate, solar PV panels, a
small windmill, and live plants.
● Total 30 km (19 mi) of bamboo was used.
● Dome supported on 18-m-long steel piles and
● series of steel ring beams.
● Bamboo treated with borax and boric acid as a fire retardant and
insecticide and bent in the required shape.
● Bamboo sections joined with reinforcement bars
● concrete mortar to achieve the necessary lengths.

19. Advantages
Strength at par with hardwood--- Bamboo extremely strong natural fibre, on par with hardwoods-- when
cultivated, harvested, prepared and stored properly.
Bamboo, like true wood, is a natural composite material with a high strength-to-weight ratio useful for
structures.
Bamboo has higher compressive strength than wood,brick or concrete and a tensile strength that rivals steel
High Flexibility - Bamboo highly flexible--during growth trained to grow in unconventional shapes.After
harvest, may be bent /utilized in archways / curved areas.
Earthquake-resistance - Great capacity for shock absorption,which makes it particularly useful in
earthquake- prone areas.
Lightweight - Bamboo extremely lightweight.Building With bamboo can be accomplished faster with simple tools than building with other
materials.Cranes and other heavy machinery rarely required.
Cost-effective – Economical--- especially in areas where cultivated and readily available.Transporting cost is also much lesser.Helps achieve cost
effective construction.
Durability - Long-lasting --as its wooden correlates, when properly harvested and maintained.
Fast Growing--Bamboo fast growing species / renewable resource which can be cultivated in most types of soil. ·
Simple designing- Designs of Bamboo components being simple, there is no need of highly skilled labour.
Reducing use of wood-- Dependency on natural forests forwood reduced thus contributing to the protection of the environment.
Eco- friendly-- As it can grow in many types of soil, bamboo cultivation is suitable for rehabilitation of degraded forests and other waste lands thus
converting them into fertile lands to some extent.

20. Reducing use of wood-- Dependency on natural forests forwood reduced thus contributing to the protection of the environment.
Promoting Employment– Creating employment opportunities especially for rural people as Bamboo mats manually woven before making them into Bamboo Mat /
Boards, Bamboo Mat Veneer Composites and Bamboo Mat Corrugated Sheets.
Promoting Welfare of society/poor- Promotes overall welfare of the society, particularly of economically weaker section.
Reducing GLOBAL warming-Captures 17 mts per hectare per year- more than any specie
Improves indoor air Quality- By removing carbon and adding oxygen when used as Indoor plant
Disadvantages
Jointing techniques – Large traditional joint types exist-- their structural efficiency is low.Considerable research directed at developing more effective methods.
Splitting – Low strength along fibres causes it to split or crack.
Flammability-Bamboo structures not fire-resistant. Cost of treatment, where available, is relatively high.
Lack of design guidance /codification - Engineering design of bamboo structures not yet been fully addressed.
-Based on research in universities / institutes around the world :
-Norms for bamboo being evolved determining physical/ mechanical properties
-Norms evaluated by International Code Council
-made part of ISO norms -- There are three ISO standards for bamboo as a construction material.
-Results show bamboo can substitute steel satisfactorily.
-Need to introduce formal education on use of bamboo as a structural material in architecture/ design and technical schools