Colombia, Manizales Photo Report of 1981 · 2017-12-30 · de-construccion-con-bambu-o.h.lopez.pdf...

HUYS ADVIES

Colombia, Manizales

Photo Report of 1981

on

Urban Settlement and Slope Control

and Bamboo Housing

Report by: Sjoerd Nienhuys

Human Settlement Consultant

Report date: August 1981

Photo’s digitized: December 2016

Location: Colombia, Manizales

Project: Management of irregular settlements by CRAMSA

By: DHV Consultants BV, The Netherlands

Photo Report 1981 - Urban Settlement Improvement and Slope Control Manizales 1

ABSTRACT

This photo report is an extract from a larger report on the slope control of the table hill of Bucaramanga

and irregular human settlements in Bucaramanga, Pereira and Manizales. These non-regulated (illegal)

settlements on the steep slopes around these cities caused deforestation with subsequent soil erosion

and an ever-increasing risk of landslides. The municipality developed a method to resettle the (illegal) occupants on the same hill sides by realizing better bamboo houses in combination with rainwater and

sewerage management.

The photo report shows how the situation was in August 1981. New lightweight bamboo house

construction is considered as an excellent option to realize on the sloped terrain, which is not suitable

for heavy concrete and brick houses without extensive soil stabilisation.

In the annex, a photo report from the CRAMSA (Corporación Regional Autónoma para la defensa de las

ciudades de Manizales, Salamina y Aranzazu) is copied about the construction of the first prototype

bamboo house and the first block of terraced houses.

Sewerage systems, rainwater drainage and constructed foot paths with steps were under development as part of the overall erosion control measurements. Sewerage cleaning by UASB reactors was under

consideration, following the designs of Bucaramanga and the earlier UASB construction in Cali.

The photo text is in some cases extended with additional information.

Sjoerd Nienhuys, Human Settlement Consultant for DGIS

Directorate General Internationale Samenwerking (Development Co-operation)

E-mail: [email protected]

Website: www.nienhuys.info

Photos: Sjoerd Nienhuys

The city plan of Manizales shows the large number of

steep slopes around the old

and flat city area.

Population expansion caused

habitation on marginal soils as no-legalized settlements.

These are in constant risk of

land slides and collapse of the buildings.

Rainwater and sewerage management and erosion

control are essential elements

as part of the legalisation of these housing areas.

Source of Manizales map: http://2.bp.blogspot.com/-eTXniyn2F10/UIpi-hjCzlI/AAAAAAAAIJk/8cn9HbZacVs/s1600/manizales+1930+padre+fabo.png

mailto:[email protected]

http://www.nienhuys.info/

http://2.bp.blogspot.com/-eTXniyn2F10/UIpi-hjCzlI/AAAAAAAAIJk/8cn9HbZacVs/s1600/manizales+1930+padre+fabo.png


The old city of Manizales, like Bucaramango was built on a plateau, being the top of a hill range. Due

to fast population growth, people started to construct their houses on the slopes, which were not considered suitable for housing.

Photo’s 1589, 35A and 36A.

Zone of Galan, being property of the CRAMSA with new lightweight bamboo houses. The long and

steep staircases of concrete are visible, left and in the centre.

The English text refers to the next photo pages.

1589 no 9A

Invasions on the slopes; Zone La Avanzada above the zone of Galan.

Up to four floors high has been constructed here. The main building material is bamboo. Roofing is

often with Spanish clay tiles, or corrugated galvanized iron sheets (CGI).

The use of bamboo is an advantage, because it is lightweight, requiring little foundation work, and has low costs. Some of the disadvantages were landslides and the burning of houses.

The slopes have first been deforested. In some locations the people started some vegetable growing.

On-site drainage of sewerage water causes water logging of the soil and in combination with rainwater from the plateau increases the risk of land slides

The project of the “Corporación Regional Autónoma para la Defensa de las ciudades de Manizales, Salamina y

Aranzazu (CRAMSA) had as focus to combat the emergencies and realise studies for better water and sewerage management. CRAMSA took the initiative to develop better lightweight bamboo houses.

See for additional information: http://idea.manizales.unal.edu.co/gestion_riesgos/inversion2.php

The above document provides detailed information about the resettlement projects which were planned

from 1980.

1589 no 30 A

Invasion settlements, which exist already for 10-15 years in the zone Galan.

The earliest invasions were on the lesser slopes, but when these became occupied the steeper slopes

were occupied, increasing the number of landslides and hose collapses.

http://idea.manizales.unal.edu.co/gestion_riesgos/inversion2.php


1589 no 28A

Uncoordinated invasions without services (water, electricity and sewerage) in the sector Galan.

The house with the red windows (in the top of the photo) is the community centre with police, clinic

and lawyer of the CRAMSA. The Annexe provides a photo report on their construction.

In the left side of the photo it can be noticed that the bamboo poles of the house have a precarious

position; below them some soil sliding has occurred due to vegetation loss.

From this picture, it can be observed that one house

recently had collapsed. To avoid further land slides

and collapse, the soil has been covered with a tarpaulin.

The two sewerage pipes going through the gully are

causing soil collapse at their lower side.

The work of the CRAMSA included the overall study

and development of a complete sewerage system of the upper town and along all the slopes around town.

To realise this many illegal or unauthorized

settlements on the steep slopes needed to be relocated.

Only a limited amount lightweight bamboo houses

were allowed to stay, provided that paved walkways,

rainwater capture and sewerage were developed in those areas.

In general terms there was no flat housing land available for all the houses on these slopes.

1589 no 34A

Very new invasions in the past 6-8 months, in this site they had planned to build the Centre of

Community Development (IPC).

The population pressure on the cities of Colombia has been very large since 1960, caused partly by the

lack of the possibility of land ownership for small farmers.

In general population growth in Colombia was already high due to lack of family planning.

Political suppression with military attacks caused the development of the FARC in 1964.

FARC = Revolutionary Armed Forces de Colombia (Fuerzas Armadas Revolutionario de Colombia).

Until 1980 the FARC mainly had confrontations with the government armed forces in the rural areas,

which had caused a substantial part of the rural exodus to the cities. The strength of the FARC armed forces was estimated at this tame at between 2000 and 4000 militants.

The invasions around Manizales and Pereira are largely caused by the rural exodus.


1589 no 11A

The work of the CRAMSA about the erosion control.

Horizontal channels for the capture of the rainwater en a structure of rapids with covers along the sides.

The grass on the steep slopes is fixed with pegs. See photo no 31A The steep gutters have speed breakers to reduce the impact of the water. See photo no 17A.

At the location where the horizontal drains enter the steep gutter, the gutters are covered to avoid that

the water is splashing outside.

The right side of the picture shows a similar steep slope, but with some bushes that still provide the

needed soil retention. Scavenging for firewood may reduce this bush cover if such is not prevented.

-----------------------------------

Erosion control has been practised by communities in South America since centuries in order to have soils for

agricultural purposes and avoid landslides.

The photo is from the steep slopes around the Machu

Picchu in Peru; over 500 years old.

The heavy stone houses in the background have stable

foundations. This depends also on the sub soil. The

subsoil in Manizales is of compacted sediments,

having less stability than this rocky soil in Peru.

The soil retention walls are made from natural stones,

the shapes fitting precisely together; these have withstood many light earthquakes.

Around Manizales, very high population pressures,

lack of community organisation and extreme poverty are causes that contributed to the invasions without any

sewerage, soil management, or erosion control.

------------------------------

1589 no 10A

Erosion control works on the right-hand side of photo no 11A

The house in the middle of the photo (height) is an invasion with a footpath coming from the city above.

Below this house a horizontal rain capture drain. The road along the top has a masoned or concrete retention wall. On the slopes, some banana or platanos (cooking bananas) have been planted.


1589 no 4A

Construction material transport for a complete room or house by means of a horse cart.

The materials are mainly bamboo and timber. The 3.2 m long bamboo culms are flattened to make the

“planks”, which are about 30-40 cm wide. These planks are dried and used for flooring and walls. Once the core house has been established, further extensions (usually vertically) will be developed, depending

on the availability of funds.

The technique of cutting the long bamboo culms to

make these planks is explained in:

http://www.basta.jabagalea.fr/tutorielbambou/manual-

de-construccion-con-bambu-o.h.lopez.pdf

The older publication from Oscar Hidalgo indicated on

the right, dates from 1974 and covers the cultivation,

paper manufacturing, construction, architecture, engineering and artisanal work.

Currently (anno 2016) many new documents from Oscar Hidalgo are accessible on the Internet, and

courses are available about the construction techniques

in bamboo. The question is whether or not these courses

are available for low-income people, whether or not sufficient bamboo plantations now are being developed,

and if the conservation methods are applied and

accessible.

http://arquitecturayciudad.com/blog/aprende-a-

disenar-y-construir-en-bambu/

The Ministry of Housing of Peru has emitted a technical standard for bamboo construction:

Norma técnica de Construcción con Bambú del Ministerio de Vivienda, Saneamiento y Construcción [ E.100 BAMBÚ ].

http://www3.vivienda.gob.pe/dnc/archivos/normas/DS_%20011_2012_%20NormaBambu.pdf

In 1972, the United Nations published a stencilled booklet: The Use of Bamboo and Reeds in Building

Construction. ST/SOA/113, which is now available in paper copy from the UNESCO library.

The authors have drawn on Bamboo as a Building Material by F.A. McClure, published by the United States Department of Agriculture.

1589 no 8A

Transport of some culms of bamboo Guadua (50-60 pesos/culm). Equals to USD 0.75 - 0.80)

The cost of an open cut bamboo plank, 3.2 m long and 30 cm wide is also 50 – 60 pesos.

In 1981, 1000 Colombian pesos = 14 USD or Euro. 60,000 pesos = USD 851.

http://www.basta.jabagalea.fr/tutorielbambou/manual-de-construccion-con-bambu-o.h.lopez.pdf

http://www.basta.jabagalea.fr/tutorielbambou/manual-de-construccion-con-bambu-o.h.lopez.pdf

http://arquitecturayciudad.com/blog/aprende-a-disenar-y-construir-en-bambu/

http://arquitecturayciudad.com/blog/aprende-a-disenar-y-construir-en-bambu/

http://www3.vivienda.gob.pe/dnc/archivos/normas/DS_%20011_2012_%20NormaBambu.pdf


1589 no 6A

Bahareque. Deteriorated houses.

Opens structure of culms of bamboo, with horizontal strips of bamboo, filled in with clay soil.

The vertical bamboos are either split culms of large diameter, small diameter culms or timber. In the photo, it can be noticed that the exterior had a lime wash as exterior finish. When the mud soil plastered

bamboo has no maintenance, deterioration will be the result. When the bamboo strips have no

preservation, they also may deteriorate due to insects. Lack of roof overhang will also increase deterioration. In the new houses, no clay soil was used, but cement-lime plaster instead.

1589 no 7A

Guadua boniga. Deteriorated house

A classical, mix of 100 kg consist of 40% clay containing soil and 60% of horse dung with chopped

grass (by volume) + 2 - 3 kg Portland cement.

Traditional houses in Latin America commonly use ‘bahareque’ as lightweight interior and exterior

wall construction material. This ‘bahareque’ consists of woven or plaited strips of bamboo, finished with mud plaster, eventually stabilized with lime. For inside walls clay and lime plaster finish is used.

For exterior walls lime and cement plaster is used and painted with lime wash.

Drawing source:

http://db.world-housing.net/building/141/

The two photos show two working methods. The top photo the more traditional open strip

structure with mud infill. The drawing right

gives the design.

The bottom photo shows full bamboo planks

and plastered with a mud-lime mix. Poor

adherence to the planks and rain causes damage to the surface.

In both cases a larger roof overhang is required and annual maintenance. However,

most houses of untreated bamboo are

abandoned after 30 – 40 years.

Two types of wall structures exist: two face plastered hollow walls, and solid filled-in walls. The filled-

in walls are not used in Manizales as this will substantially increase the building mass. The hollow walls provide some thermal insulation due to the standing air in between them.

The following document gives details about bamboo construction techniques for social housing, inclusive foundation design, seismic design, culm and floor diaphragm design, timber floor and roof

design: https://sheltercluster.org/sites/default/files/docs/norma_andina_sin_portada.pdf

http://db.world-housing.net/building/141/

https://sheltercluster.org/sites/default/files/docs/norma_andina_sin_portada.pdf


The roof overhang provides some protection of the plaster, but there are no gutters. On the lower photo

the quality of the wall surface is getting worse going down. By having sufficient roof overhang and installing roof gutters, less damage to the walls will occur.

In general, the roof overhang of the new bamboo houses is larger on the street and rear side, than in

between them, because the houses are being built close to each other or even fully connected.

When the houses are being built as terraced (connected) house it is recommended to fill the bamboo

wall solid to reduce sound transmissions.

The practical life time of most bamboo houses is between 30 to 50 years. When the children leave the

parental house, they built their own house and eventually the parental house is written off.


The settlement upgrading process by CRAMSA in

Manizales comprised of the following elements: Rainwater and sewerage capture of the upper

city and piped draining down the hills to the

rivers following the models of Bucaramanga.

The option of developing the black water or sewerage cleaning by UASB (Upflow Anaerobic

Sludge Blanket) system following the example

of Cali and following the developments in Bucaramanga.

Removal of squatters from unstable grounds and

slope stabilisation. Creation of pathways over the sewerage systems

and connecting the dwellings to these sewerage

systems.

Design and development of new, high quality lightweight bamboo houses along the pathways.

The photo on the right gives an impression of the size of the stepped pathways that were developed. Along

the pathways new houses have been constructed.

1589 no 26A

New houses with corrugated galvanised roof sheets

and roof gutters to capture the rain water. The

walkway shows an open gutter along the steps for draining surface water. The sewerage is built into

(below) the steps.

These houses were built by the CRAMSA. The exterior finishing is with cement-lime plaster and

white lime finish. The constructions served as

training ground for local builders and showcases for other inhabitants who need to be moved and resettled

in relation to the soil management.

The new houses are only one or two floors with a

balcony. With the house on the right-hand side of the

photo, the owner has finished the lower storey with

an additional room, having a shuttered window.

The houses have adequate roof overhang and gutters

on the street side to protect the outside of the plastered walls from the rain.

These lightweight houses have obtained a permit, and are connected to water supply and sewerage.

The Annexe to this paper includes black and white photo’s of the development of the prototype house

and the construction of this terraced housing block.


The gutter from the corrugated roof ends above the

concrete steps of the footpath.

This roof gutter is made of bamboo.

The round cover is an inspection manhole for the sewerage system.

The drink water piping runs alongside the footpath.

On the left, between the footpath and the houses

small platforms have been created.

The legalisation of the plots and the houses will

imply that the houses will get metered electricity

and water supply.

1589 no 25A

Rear side of the new terraced

houses that were recently built by CRAMSA (see the Annexe).

The staircases are from timber.

All roofs have gutters.

Photo of the floor structure from below. Sewerage piping of waste

water connected to the toilet and

kitchen.

The support structure is from

bamboo, but the flooring is from

common timber planks when the owner has sufficient finances.

With inadequate finances the

owner can use bamboo mats.

The clusters of support posts are

constructed on small concrete foundations. This way they are not

into contact with the soil, which

will improve their life time.

In the design of the houses, two

important environmental aspects needed to be taken into account:


A: The annual rainfall in the area, the main cause of erosion of non-stabilized soil.

B: The seismic activity of the region. Seismic forces may easily cause land slides of waterlogged slopes and non-stabilized slopes.

Rain fall in the district of

Caldas.

The city of Pereira lies on the south west of Manizales. The

amount of rainfall here is about

2 m per year.

http://2.bp.blogspot.com/_XUaySiA3q20/SFuo0PpMsQI/AAAAAAAAAmI/5k87M-5nSus/s1600-h/caldas-PRECIPIT.gif

Seismicity of Colombia.

Manizales and Pereira are located in the red

zone at 5 degrees north.

The red zone has a possible seismic strength of maximum PGA = 0.25g

Peak Ground Acceleration.

Lightweight and elastic structures such as

bamboo and timber houses are little affected

by seismic forces, but cracks in the plasterwork will easily occur during a

earthquake.

However, the stabilisation of slopes and soils are very important.

http://www.unperiodico.unal.edu.co/dper/article/nueva-falla-geologica-altera-mapa-de-amenaza-sismica-en-colombia.html

The reforestation of the slopes with bamboo will reduce water logging in the soil and absorb the moisture. Bamboo will also provide construction material and material for user goods and artwork.

http://2.bp.blogspot.com/_XUaySiA3q20/SFuo0PpMsQI/AAAAAAAAAmI/5k87M-5nSus/s1600-h/caldas-PRECIPIT.gif

http://www.unperiodico.unal.edu.co/dper/article/nueva-falla-geologica-altera-mapa-de-amenaza-sismica-en-colombia.html


Tangential and

radial split bamboo has excellent

properties for

making a large

variety of household products

such as baskets.

These photos were taken in South

Asia.

The local production of bamboo on the slopes for soil stabilisation will

therefore also allow employment development.

In India and China, a very large number of bamboo articles for daily use are available, including artworks and furniture.

-------------------------------------------------------------------------------------

The following black and white drawing and photos are from a report by the Manizales projects architect

D. Castro.

Design principle 2-3 floors. Houses under completion.

The overall balloon frame of a bamboo house with two floors.

Several floor supports come together on one foundation point.

In some cases, the lowest space is used for housing as well. Floor finish is from stiff and flat timber planks, but when the

house owner does not have sufficient finances, the more flexible

bamboo mats are used.

In this house on the left, the bottom section is closed off,

being often used for storage and cattle or chickens. The

house has a roof of Spanish tiles. This is rather heavy but less warm than the commonly used corrugated metal

roofing sheets. The latter requires good thermal

insulation under the roof sheets.

A few years later small fibre cement roofing tiles came

on the market. The use of bamboo tile roofing (laid the

Spanish way) was not used.


Reconstruction of the main road in the zone

Galan. The flat terrain below is the area for the construction of 48 Guadua bamboo houses for

CRAMSA.

This is the access to the steel bridge. One of the two old steel suspension bridges which crosses the

river has greatly deteriorated. One will be

renovated to allow light vehicles.

Reconstruction of the main road for vehicular

transport, such as for waste collection.

In the new urbanisations, no area is foreseen for

parking of vehicles.

Erosion control channel with a footpath along the

lower side.

It is suggested that these types of channels are

allowed to be used as foundations for the

lightweight bamboo Guadua houses.

From these slopes, sub-terrain water will filter out and be collected in the horizontal gutters. The

slopes have been covered with grass sods. The

vertical gutters avoid soil erosion by the water

running down.

Larger concrete tubes have been supplied for the

further canalization of the rain and waste water towards the river.


The grass sods on the slopes are held in place with timber pegs until the roots

develop.

In this location, someone has destroyed the cover. Walking on the grass or cattle

is not allowed here.

Reconstruction works are on the way for

the canalization of the sewerage.

This old house has a structure in which the support structure is on the outside.

This way the occupants have a flat inside

wall surface.

In later developments the outside

bahareque facing can be made, with a durable lime-cement plaster, creating an

insulating cavity wall.

This house however, stands directly in the soil, causing speeded up deterioration

of the bamboo support structure by the

rain.

Canalization works for the down drains. These have alternation horizontal and inclined

sections. Where the horizontal section end and

the inclined section starts, the canals are covered. This is to avoid that the speeding

horizontal water jets out of the channel.

Inspection hole in the road under construction.

The side of the footpath has been constructed

already.

From the inspection hole the channel

continues towards the river (last photo). In this

channel flow barriers are constructed to reduce the speed of the water going downhill.


Water filtration hole for domestic

water supply. Women collecting a bucket of water from this water

source.

With increased population density in the higher sides of the slopes, this

water will be contaminated.

This will be especially the case when house owners are not connected to

the sewerage system but have built

pit latrines on-site.

Regularisation of the settlements

after the soil stabilisation will allow

the development of sewerage systems, paved walkways and water

supply.

Lower section of

Manizales with older

houses.

This area has a mixture of

legal housing along the

road and invasions in the higher slopes.

Most houses here are also of bamboo and appear to

be in different stages of

development.

END OF THE SECTION ON MANIZALES.

The next section is a copy from a photo report from CRAMSA.


ANNEXE. Reproductions of black and white photographs of the construction of the June 1980

prototype house and the first block of the terraced houses from colour photo 26A.

View from the hill above. The prototype house was built on nine concrete foundation blocks.

The design is a three-storey balloon frame house, with inside and outside bamboo mats (plastered).

The floors in the prototype house are made from planks, which are more flat and stiff than the traditional bamboo planks. The wall

panelling is made from flattened bamboo culms and tied with

galvanised wire to the vertical support culms, both on the outside and the inside of the building.

The bamboo is used as structural element, enclosure, finishing, furniture, utensils and decorations.

The cement coating on the matting is different from the traditional bahareque structure on bamboo

strips. When the cement-lime plaster is properly adhered to the bamboo, it is more durable, hygienic and has a neat appearance. A good-looking house design is important for stimulating replication.

The exterior cement plastering receives a final and white lime coating.

The roof overhang provides shade and prevents the rain affecting the walls.


The outside is plastered from the top down, then lime washed and the scaffolding bamboos removed.

The roof overhang on the sides of the buildings are smaller since other buildings will be situated here.

The working method of settlement

improvement is abased on re-

settlement in the same zone, without eradication of the

population. Urban upgrading and

improvement of the housing.

Once the prototype house was completed, a line of terraced houses was built as a continuation.

In this case the line of houses were built first, and later the pathway construction with the sewerage, water supply, steps and open gutters were constructed. Photo’s are made from both sides.


Several houses were constructed with one habitable floor, others with two. Later some owners filled in the lower storey to make an additional room or storage space. Roofing is from CGI sheets.

On the rear side of the buildings timber stairs were made to allow movement between floors.

The difference in roof overhang between street or valley side and those between the houses is noticeable here. The roof gutters were not yet added in this building phase.

The improved traditional bamboo building method and sewerage control allowed lightweight houses on strongly sloped terrain without increasing the risk of landslides due to rain or earthquakes.

*********End File***********

Colombia, Manizales Photo Report of 1981 · 2017-12-30 · de-construccion-con-bambu-o.h.lopez.pdf...

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Transcript of Colombia, Manizales Photo Report of 1981 · 2017-12-30 · de-construccion-con-bambu-o.h.lopez.pdf...