Photos from Anna Lang–unengineered construction

A set of images showing low-rise, un-engineered construction:

Some Observations on Typical Housing Construction

California structural engineer Craig Cole is currently (2/15/10) in Haiti, and has offered observations on typical housing construction, and the current housing situation.

Photos of typical housing construction can be viewed by clicking here: Typical Haiti House Construction.pdf

Observations on the housing situation can be viewed here: Haiti Housing Issues some observations.pdf

Haiti’s Poor Construction Materials

Click the following link to view the full article:
http://www.ireport.com/docs/DOC-405042?ref=email

Eduardo Fierro presentation at UC Berkeley, January 26, 2010 on his reconnaissance trip

R. Clarke: Observations from Quick Damage Assessment Visit

Richard Clarke, Lecturer at the University of West Indies was a member of the CARICOM (CARIbbean COMmunity (a group of the English-speaking islands of the Caribbean including Jamaica, Trinidad, Barbados, etc) group that was asked to go a few days after the earthquake.  His function was to assess existing non-collapsed buildings for possible use as temporary medical facilities. Based on his very preliminary survey, he offered some observations on construction practices:

1.       A prevalent form of earthquake-resisting structural system used in Haiti, especially for housing, is a particular system used extensively in Europe and is called “confined masonry”.  (also view www.confinedmasonry.org).   In Haiti the blocks are mainly of concrete vertical cell units 6” thick (and 8” high x 16” long).  I do not recall seeing rebar larger than ½”in the debris of any of the housing structures.  The typical Haitian house has a concrete roof, probably for hurricane resistance.

2.       Interestingly, in many instances of multi-story construction, flat-slab reinforced concrete is the gravity load system.  It is also common to find that the floor slabs are of “concrete composite” construction.  That is, blocks are used as fillers and permanent formwork, but space is left on either side to facilitate the placement of the rebar.  The concrete is then placed with a topping.  I am not sure if fabric reinforcement is placed in the topping, or its thickness.

3.       The confined masonry has reinforced concrete columns integrated with the blocks and sometimes these are extended upwards thus acting like columns supporting the concrete flat-slab floor.  It seems that collapse was frequently due to shear failure of these columns, which are generally quite small (no more than 10”x10”).  Punching shear failure of the floor due to inadequate rebar and/or shear strength of the flat-slab is also probably another failure mode.

4.       It also seems that for the RC framed buildings, the strong-column-weak-beam capacity design rule was not followed since the columns seem too small.

5.       Many structures did not collapse and given the existence of engineers in Haiti, I expect that in the final analysis, the main cause of collapse will not be primarily due to lack of knowledge, but rather the lack of the input by a professional engineer in the design and construction of the collapsed structure.  This will be understandable given the extensive poverty which will promote the use of substandard materials, and irregular structures.

Photos from his visit are available for viewing at http://profile.imageshack.us/user/rpclarke

Poor construction in Haiti before the earthquake (from Miami Herald)

The lack of enforcement of laws and bureaucratic bickering have Haitians living, working and studying on virtual quicksand foundations.

Read more here: http://www.miamiherald.com/582/story/1435690.html

Fierro part 4 20100118

Fierro photos, part 3 20100117

Fierro photos, general, bldgs w/heavy damage

Recent construction (est. 5 years old). Collapse at 1st-2nd floors; light concrete frame with masonry infill.

Landslides common on slopes around Port-au-Prince; many rubble or unreinforced masonry retaining walls failed.

Partial collapse of unreinforced rubble stone retaining wall.

Downed utility pole due to landslide; power lines and transformer down with oil and PCBs leaking on roadway.

Overview of devastation of hillside shanties. Landslides may have contributed to collapses near center of photo; construction at upper right on wider terraces appears intact.

Presidential Palace in Port-au-Prince. Much of first floor still intact with windows unbroken; complete collapse above first floor.

Presidential Palace. Building E-shaped in plan; very light reinforcing evident in failed columns near entry.

Recent construction (est. 5 years old). Collapse at 1st-2nd floors; light concrete frame with masonry infill.

Recent construction; close-up of inadequate reinforcing in columns at top floor.

Collapsed corner building; structures on either side intact.

Collapsed corner building; close-up of smooth hairpin reinforcing bar.

Collapsed corner building; undersized smooth bars.

5-story confined masonry building; collapse due to soft 1st story, short columns at 2nd story, and perhaps inadequate splices of column bars.

5-story bldg; close-up of 2nd and 3rd floor beam-column joints without shear reinforcement (2nd flr joint and much of 2nd floor column intact with shear crack indicating top of masonry infill; appears all column bars spliced at 3rd floor joint).

Close-up at joint. Note smooth column bars, deformed beam bars and no hoops.

4-story unfinished concrete building collapse; leaning on adjacent structure. Failure due to open front, undersized columns, heavy slabs, and inadequate reinforcing.

4-story collapse; close-up of corner “column” at 2nd and 3rd floors.

4-story collapse; close-up 3rd story beam-column joint showing small, smooth bars and no hoops. Appears column bars may be lapped in the joint (see tie wires).

Collapsed 2- or 3-story reinforced concrete building.

Unreinforced masonry building with mix of brick, concrete block and rubble stone. Appears 2nd story collapsed.

Front view of collapsed Port-au-Prince Cathedral; towers collapsed. Remains of steel framing evident at base of left tower.

Cathedral collapse; many columns and wall sections still standing but roof completely collapsed. Note steel framing in wreckage and unusual reinforcing in dangling columns.

Cathedral collapse; dangling column.

Cathedral collapse; close-up of flat bars (est. 1/16″x1″) used to tie longitudinal steel together. Wikipedia says cathedral built between 1884-1914; dedicated in 1928.

Street scene showing collapse of downslope buildings at left; buildings at right all intact.

Unreinforced masonry building with mix of brick and rubble stone. Front wall still standing but daylight visible through window at left indicates roof collapsed.

Concrete and masonry at 1st floor with wood framing and corrugated metal panel siding above. Building still standing in spite of collapse of front and side wall and missing floor. This structure independent from concrete and masonry building at right.

2nd floor column damage; columns restrained by concrete handrail (short columns) and one damaged by pounding from stairway of adjacent building.

Close-up of short column failure. Bars undersized, smooth, and no sign of hoops. Suspect use of beach sands in concrete may contribute to corrosion.

Building abandoned prior to earthquake; large expanse of roof currently unsupported but hanging on somehow.

Landslides common on slopes around Port-au-Prince; many rubble or unreinforced masonry retaining walls failed.

Colombage Construction

Information provided by EERI member Randolph Langenbach.

This photo found on Facebook (and presumably taken by) Gwenn Goodale Mangine within 24 hours of the earthquake clearly shows a building with its upper story constructed of “colombage” (the French word for “half-timber” or known in Turkey as “hımış” and in Kashmir as “dhajji dewari”) construction. The lower floor appears to be unreinforced stone masonry. The infill in the timber framed upper story is rubble stone. It is damaged – but it successfully resisted collapse, not unlike similar construction in the damage districts of the 1999 Marmara earthquakes in Turkey, and the 2005 Kashmir earthquake in Pakistan and India. Since colombage is a common French construction, found particularly in Normandy – it will be important in any reconnaissance of the Haiti earthquake to include its manifestations in Port au Prince. It will be valuable to see if other examples exist to examine how well the buildings fared in the earthquake, and if any did collapse – and, if so, why. Since this is a pre-modern form of confined masonry construction, a study of it may be able to contribute to EERI’s confined masonry project, and RC confined masonry may also be considered as suitable for reconstructions in Haiti. It may also be a valuable alternative to the badly constructed cinderblock and reinforced concrete frame construction that has done so badly in the earthquake. In a country like Haiti, it is important to promulgate forms of construction that both are (1) derived from indigenous construction methods that can thus be easily understood by the general population, and (2) can be constructed by relatively untrained (and often illiterate) owner-builders with little engineering, quality control, or regulatory oversight.