Chile Quake Collapses Adobe Homes

The part of the headline about yesterday's earthquake in Chile that immediately caught my eye was that the earthquake had collapsed some adobe homes. This is a recurring theme, like trailer homes and tornadoes.

A quick search of adobe and earthquakes yielded this little gem: http://www.world-housing.net/wp-content/uploads/2011/06/Adobe_Tutorial.pdf

As you labor with each glob or block when building your mud homes, please consider the probability of all that weight crashing down on your loved ones and design and build accordingly.

Thanks, I appreciate the link.

This is a sad, yet germane reminder that "cobb" and related clay architecture IS NOT the "simple deal," that so many make is seem to be. The events in Chili are a grim reminder of this, and one that in the next few decades we may see visited upon us as well with so many "natural build" DIYers falling in love with "clay architecture."

I to love this medium, yet do not support or condone the use of it without structural armatures being designed into the matrix of the building. Even traditional Pueblos that I have helped restore on Hopi, Dine, and Pueblo reservations have architecture elements that reinforce the design.

Here is a link to a friend and colleague who addresses the wonders of timber, stone and clay architecture for tectonically active locations. It can be done, is appropriate, but MUST be facilitated correctly.

http://www.conservationtech.com/index.html

http://www.traditional-is-modern.net/index.htm

http://www.ewpa.com/Archive/2012/july/Paper_130.pdf

http://etd.lib.metu.edu.tr/upload/12605023/index.pdf


Regards,

j

Yes. Most of the Spanish Missions built in California have either been demolished, or severely damaged by earthquakes.
The Spanish had centuries of experience from the Moorish period building large adobe structures.
La Alhambra is a classic example that still stands today.

However, methods that were suitable in North Africa and Spain were not suitable in California's quake regions.

Did you read about the landslide and other cement and timber houses being destroyed.
I know that here in Boston, the house that they have are not build to withstand landslides or tsunami or even LITTLE 8.2 earthquake.
So I think it might be let about the houses being adobe and more about it just being a strong earthquake with over 9 aftershock

S Bengi, you are comparing apples to oranges. The issue is mud homes and earthquake survivability, though landslides and tsunamis are often associated with earthquakes.

All traditional construction materials and methods need to be adapted to modern seismic standards. Modern materials and methods can also fail catastrophically in earthquakes when shortcuts have been taken in design and construction. The concern with mud construction is the tremendous weight involved. There are things that can be done to keep mud structures from collapsing in strong earthquakes. It takes some of the simplicity out of mud and it may constrain some aesthetic and artistic flexibility, but a creative mind ought to be able to work with it.

Most of the deaths (close to 50,000) in Bam, Iran occurred not in the old mud citadel but in modern adobe-walled homes. The old citadel did collapse, but there were only a few people inside at the time. The interesting thing in the article on Bam was the role termites had in the damage. Apparently, termites like the straw used in adobe and cob, both of which were used at Bam. The recommendation was that any cellulose material used in mud construction should be treated with borates.

Some of the modifications recommended in the article I found look very similar to the what Scott Howard is using in his Regenerative Home.

Hi Folks,

This topic is germane and current to events going on today in permaculture...clay architecture out of context.

John P., clearly pointed out a "foreign vernacular" that did not belong in the "new world," architecturally (and culturally as much of the architecture was also a cultural and religious statements of domination over the indigenous Native cultures.) When any vernacular is taken our of context, there is very often failure...be that a vernacular species of animal/plant or architecture.

I would further expand that John's example also suffered from not being as well designed and built as the originals back in North Africa and the Iberian peninsula.

Hi S Bengi,

I think I understood the gist of your comment (please correct me if I misunderstood.)

You are trying to say that:

"Any type of architecture, mud or modern steel, subjected to very high tectonic event is going to suffer damage."

You are correct, yet the "tiger in the room," in many regions of the world is actually applying what we have learned over the last 5000 years from traditional builders in active tectonic regions. You brought up Boston, and that is on the East Coast with tectonic plates capable of huge events as they just build up pressure over the centuries unlike the West coast the routinely release them. When we get the "big one" in the East, it is going to be catastrophic. I would further point out that even in most cities on the East coast that are adopting "tectonic codes," these still will fall very short of what will work, as the building industry is still more aimed and "profit" over actual applicable "real world" standards.

Hello Andrew P.,

You have brought up some points I must either clarify or perhaps challenge, if you don't mind...

All traditional construction materials and methods need to be adapted to modern seismic standards.

I really have a hard time with that, as most "modern standards," barely meet the minimum of "traditional standards," as you would find in the Hindu Kush or places like Japan which have events every day, and large ones several times a year. These regions, and their traditional building cultures have forgotten more than most modern "earthquake PE" have even begun to learn...Yet, we are to follow modern standards? Not a very good idea.

The concern with mud construction is the tremendous weight involved.

Sorry, this is what many "experts PE" focus on, yet this is not the real issue at all. It ties into the premiss of risk management of preserved risk vs. actual risk. It is the lack of lateral stability, and proper flexibility in the structure. You can build traditional clay, stone and timber architecture that is way more tectonically stable than steel, and I have seen little RC (reinforced concrete) that will even last a fraction of the time in these regions that traditional ones have and do.

There are things that can be done to keep mud structures from collapsing in strong earthquakes. It takes some of the simplicity out of mud and it may constrain some aesthetic and artistic flexibility, but a creative mind ought to be able to work with it.

100% AGREE

This has been one of the biggest "swallow hard and breath," points for me to deal with here at Permies, and in the rapidly growing "natural build movement." All these folks being told they can "just do it," "its easy," or any other altruistic emotional embodiment that is getting put out there about architecture...especially CLAY! I would conservatively say that more than 30% of the modern natural clay architecture I see is very wanting in good design and implementation, and many of these "experts" teaching and facilitating rely probably shouldn't. (apologies to all for sounding so bloody arrogant...I am just very concerned that most of them can't answer the most basic of questions and give fluid and dynamic responses to the one they think they can about architecture and its design.)

Most of the deaths (close to 50,000) in Bam, Iran occurred not in the old mud citadel but in modern adobe-walled homes.

I must add...like Haiti, China, etc...also RC augmented, and modified traditional clay building suffered worse.. Concrete DOES NOT far well in tectonic zones compared to more ancient and traditional modalities.

I strongly encourage all reading this thread and thinking of building with clay...look at the links I provided above and ask as many questions of me as you would like...I will do my very best to respond.

Jay, the concern with the weight of mud construction is not in engineering a stable structure but in the damage done if that structure fails.

Given a two foot wide wall of mud, four or eight inches of fired brick or stone, hay bales, a timber frame infilled with brick, tile, light clay straw or wattle and daub, a conventional two by four wall, which one would most rather have their child sleeping next to in the event of an earthquake?

RC is in its infancy when compared to traditional methods. Every failure brings about new standards that await the next and greater challenge. I see buildings built in the '60's and '70's, many of them strikingly beautiful, having to be torn down or significantly rebuilt (uglified) in order to meet new seismic standards. When our freeway system was being rebuilt here prior to the 2001 Olympics, I noticed that the old concrete columns were given steel jackets but the new ones were not. I was told that the old ones needed it, but the new ones were built to improved formulas that gave better flexibility.

The primary weakness in RC is not in the design but in how well the design is followed. Use of out of spec material and workmanship are a problem with all methods.

Traditional vernacular architecture does not always improve and adapt after catastrophic failure. It depends on the culture. Often, people will rebuild the same high-risk structures that killed their families because it is expedient and it is the way it has always been done.

If one must, or chooses to, build with mud, and I might be inclined to do so myself, use the best methods available to date. There has been a lot of research and testing done that can be applied to building mud structures, much of it is not particularly expensive or complex.

Handmade and owner built does not have to equate to shoddy or unsophisticated (which often can be applied to what "professionals" do). Mud homes can be built to survive powerful earthquakes but it takes some thought and skill. Mud construction, good mud construction, is not simple. Study it, then practice until you get it right, then build a home. Notice, I did not say not to do it. Just do it correctly.

Jay, the concern with the weight of mud construction is not in engineering a stable structure but in the damage done if that structure fails.

Agreed, yet no more so than steel, brick, and RC, which built to current modern standards as many are, they fair less well in tectonic zones than does originally build vernaculars in earth, stone, and timber.

Given a two foot wide wall of mud, four or eight inches of fired brick or stone, hay bales, a timber frame infilled with brick, tile, light clay straw or wattle and daub, a conventional two by four wall, which one would most rather have their child sleeping next to in the event of an earthquake?

In real world application of architecture I always advise folks to look to the vernacular of a regions, which inevitably is the most enduring for a given biome, whether you are talking of Anasazi Cliff dwellings, Koti Bannel of the Hindu Kush, or Minka in Japan subjected to enormous tectonic events of both wind and earthquake. With that said, I want my Son, who sleeps near a timber and log wall now, (and the children of my clients...and their great, great, great, etc, etc, grandchildren) to be living in the most succinctly designed, german, and sustainable natural building possible. 2x architecture has in general been give a viable economic life span or 20 to 30 years before requiring some form of major intervention as they are being built and designed today.

So I would be more than fine with any of those natural systems (when done properly) over a 2x wall.

RC is in its infancy when compared to traditional methods.

I agree RC is in its infancy, and probably will never make it to even its "teens" at the rate it is going. For one, we relearn new facts each year about "lime architecture" (which concrete is part of) that reflects just how much "reinventing of the wheel" we have done since the Industrial Revolution (IR) in the area of concrete...most of it much poorer in quality than we had 2000 years ago. (Remember the Roman Parthenon is still the largest unreinforced concrete structure in the world, and much larger than many RC structures that are a faction of its age and failing fast. We have even learned (learning) that many of these ancient amalgamations may not even be OPC as we think of it today, nor even a "natural cement," but more like a geopolymer in its use and design. We haven't even begun to understand and improve upon the pozzolanic reactions that our forbears had perfected, so I don't really see RC getting much farther before we figure out that it is not, "environmentally sustainable" the way industry has been doing it over the last 80 years, and that without a huge fossil fuel bill, giant carbon footprint allowances, major political involvement by lobbying interest on the behalf of the concrete industry, and subsidies with contracts, this industry would die rapidly.

The primary weakness in RC is not in the design but in how well the design is followed. Use of out of spec material and workmanship are a problem with all methods.

I assure you there are many, many more weaknesses than just "design, with OPC used in RC today. I avoid the stuff wherever I am able to, and would much rather use stone, earth, and timber for all domestic and even many commercial architecture projects.

Traditional vernacular architecture does not always improve and adapt after catastrophic failure. It depends on the culture. Often, people will rebuild the same high-risk structures that killed their families because it is expedient and it is the way it has always been done.

I am not sure what you are basing this one, if you have actually built in these vernacular systems, or traveled to the regions of the worlds that I have reference (I have done bother) but that statement is somewhere between simply false and obtuse. In impoverished regions that have been stripped of resources by the "first world nations," and dominated by Anglo European Culture for the last 1000 years there are no doubt issues. Nevertheless, wherever these cultures have been left to their own devises, almost the complete opposite or your statement is true. We do not have a single example of modern architecture built in the last 60 years that are enduring as well than just a fraction of most vernacular structures on the globe, and there is little doubt that these examples of modernity will last anywhere near there life spans of the vernacular without major intervention. The senescence of current trends in modern architecture is anything but sustainable or enduring, nor are they planned to be so. The "first world" architectural systems are like the rest of society...consume and through away. I study this subject in great depth, and not to bore the other readers, could go on for some time relating and reference countless examples without even opening once to my files or activity researching what I write about on this subject. I would suggest you really read and study the links I provided in the begining of the post as Professor Langenbach's work is extensive, and his knowledge being consulted by many governments on this very subject.

....much of it is not particularly expensive or complex.

I don't disagree with this per se, as I worn folks all the time how labor intensive this can be, yet will also point our that the complexity is only depended on the cultural knowledge and actual real world experience with this medium. Rembmer the majority of the world still builds in earth, stone and timber...In that way most "first worlders" are very much amateurs at best.

Handmade and owner built does not have to equate to shoddy or unsophisticated (which often can be applied to what "professionals" do). Mud homes can be built to survive powerful earthquakes but it takes some thought and skill. Mud construction, good mud construction, is not simple. Study it, then practice until you get it right, then build a home. Notice, I did not say not to do it. Just do it correctly.

Could not agree more...but lets call it "Clay" or "Earth" architectures as that is what the vernacular in most languages translates to, as "mub" is a pejorative, and not accurate description of most...Clay- Slip Clay Straw/Chip-Cob (Cobb-Clom)-Tabya-Adobe-Bousillage-Colombage-bajareque-土壁 (Doheki), 土塀 (Dobei) etc, etc, etc,...formulas and matrixes used in earth architecture.

Regards,

j

[Jay, I am not alone in my observations, nor do I consider them false or obtuse. I do not share your condemnation of RC or your embrace of traditional methods over modern, I do not ascribe superiority to either, so we agree to disagree. I won't burden the forum with discussion of it.]

I found this document, NOTES ON THE SEISMIC ADEQUACY OF VERNACULAR BUILDINGS. It comes from the engineering side and wades pretty deep into architectural philosophy (just skip to the relevant parts, if your eyes start glazing over). I like it because it highlights vernacular bamboo wattle and daub (and daubless) architecture in Ecuador and Colombia. The examples I have experience with were daubless to let the tropical breeze through, though there are some beautiful homes in the older sections of Guayaquil that were daubed, plastered and painted. Because the city has burned down a few times, most notably about 120 years ago, use of bamboo panels in the city is discouraged and is usually only found in invasion areas. It is still used extensively in rural areas, even in the residences of wealthy haciendas. Most construction now is with the globally dominant RC post and beam with light masonry infill (they make great solar ovens with their small windows and tin roofs).

Hi Andrew, PLEASE! don't go, or take offense if I seemed overly challenging...

ANY good academic discussion on a subject like this requires there be engaged individuals with interest, and knowledge that may have "some," counter view points. Discussing, and engaging in those differences can lead to new insights in both parties (if they are truly engaged in learning and understanding.) When I engage in a conversation like this as an academic, teacher-facilitator, or as business person dealing with a client; I present information, and my interpretation of it. I support that interpretation with evidence from reliable sources, including direct empirical evidence, AND VERY IMPORTANT, conversation-debate with intelligent people, like you often find on Permies. If, I am unable to sufficiently support a position (or facet there of) on a topic, (i.e. my interpretation) and/or concept, then I learn and change...or...I change others and they learn. The real truth is both parties typically grow, and gain wealth of spirit and knowledge by such exchanges, as does the audience, and other around them.

I do believe some of your position is flatly lacking complete depth, and is obtuse... ...that doesn't make me "right," or "wrong"... Sorry, if my choice of words offended, as I meant 'obtuse" in the true academic way (imperceptive-uncomprehending,) not as a slander at all...I also need to learn as a writer and teacher that certain words have an undesirable effect, and I do use that one both ways, and should only use it in the latter...apologies for that.

I very much enjoyed Professor Gutierrez's paper when it originally was presented for review for those that could not attend the conference. If memory serves it did get challenged in some ways by other academics like Professor Langenback, yet overall, Professor Gutierrez work then, and since is more in support of indigenous vernacular architecture than against, he just holds the position that it must be done well, and in some regions requires additional augmentation in strengthening...I could not agree more with that part of his position.

So for the sake of learning, and expanding both of us in understanding "germane architecture," let us (and/or other readers) highlight specific elements, and dissect-investigate those. With that said, since you presented Prof. Gutierrez's paper, take that as a syllabus and outline where you believe vernacular architecture is inferior to modern, as I contend (when vernacular is done in context to standard-NOT-augmented, neglected, or poorly done, as is so often the case in many comparisons like this one) it more than exceeds the contemporaries of modernity in durability, resistance to events of duress, sustainability and practicality for a given region, and its people.

Regards,

j

Hello Jay,

I know this thread has been dormant for a while, but I wanted a clarification.

I to love this medium, yet do not support or condone the use of it without structural armatures being designed into the matrix of the building. Even traditional Pueblos that I have helped restore on Hopi, Dine, and Pueblo reservations have architecture elements that reinforce the design.

Do you mean, in seismically active areas, or everywhere? In other words, do you only see clay as an infill material?

What kind of reinforcement do the southwest traditional adobe structures have?

If I might chime in for a quick comment, there really isn't such a thing as a geologically inactive area, though some are more active than others, so I would caution to be careful everywhere.

One of the first deaths from Wednesday's quake in Chile was a women crushed to death by a collapsed adobe wall at a restaurant.

Andrew Parker : Yes ! Well said, and much (Regional) Seismic Activity/History has been lost or ignored.

Also after past Seismic Activities it seems that well-intended and politically inspired bandaid solutions get plastered onto the

existing / remaining structures with inadequate regard for scientific Lessens learned .

The entire Urban area of San Francisco is a patchwork of Historic and period and modern Urban/Suburban construction -

Much of it setting on Fill dumped into the San Francisco Bay Basin ! *

The Fact that these loose soils will "LIQUIFY " during most severe earthquakes is barely considered in preparedness plans

that are Focused on much more regional solutions.

Part of the problem here is that scientists and "urban planners '' rarely look back for clues - be leaving that ''Modern Science ''

is the superior teacher.

So when discussing "Vernacular'' Building types we must remember that some locations for buildings like flood basins, and

old dumps, and regions with Karst-type rock formations (sinkholes) should be avoided

{ Don't get me started on Ocean-front properties, flood insurance, or preparations ( read lack of planning ) in Lahore and Tsunami

Regions }

For the good of the crafts ! Big AL

* as is much of Boston Mass - a famous early 1800s Earthquake near Madrid Mo. was powerful enough to cause parts of the Mississippi

to ''Flow Backward" and caused church bells to spontaneously ring in Boston and New York ( mostly lost history ) A.L.

I see cob as primarily an infill material,  weather it's cob alone or mixed with some insulating material. Of the 20 or so cob buildings that I've visited, I expect one or two,  to survive a quake.

Hello Gilbert,

I will try and give you as short/concise a response as possible.

I have been following along on your other post as you discuss this mater in depth with Terry.

Simply put, as a professional builder in traditional and vernacular forms (with or without PE assistance) I will not build structural earth or masonry structures of any type that do not have a traditional armature framework of wood. The only exception to this is the work I perform/consult on in Historical Restoration.

Can....Clay- Slip Clay Straw/Chip-Cob (Cobb-Clom)-Tabya-Adobe-Bousillage-Colombage-taipa-bajareque-木舞 (Komai = lath)-土壁 (Doheki=daub), 土塀 (Dobei=earth wall)...be design and built to withstand tectonic seismic events and climate events YES!!!

Rarely (in my view) is this the case by DIYers, or novice to this vernacular and historical system, and even with good solid understanding and traditional understanding these buildings are weaker than other vernacular forms...even in the same areas...

The risk is simply not worth it to me professionally, when it is seldom difficult to attain the necessary materials to create a stronger and more durable system while still following traditional vernacular (or natural design parameters.)

Regards,

j

I just skimmed through this discussion, briefly, read some of the reports that should come to the same conclusions. Lets get down to the nuts and bolts of problem with adobe/COB or concrete stand alone construction.

1. The accelerated force is not the same everywhere, that is why we in the USA and other parts of the world have seismic zones. Design requirements to resist will vary. There is nothing being "ignored" here. For the most part, CA and the SW states are VERY strict!....many see as being ridiculously over-kill and I'd have to agree on some of that. I read about it on Architect forums. In US zones A-B there is little concern and rightly so, no need to over design and the high cost of highly resistive structures could put builders out of business.

2. Weight is not the issue in causing failure, distribution of weight and CG location is. Weight as in heavy bond beams/roofs/upper walls causes the biggest moment arm to the ground forces and bending moments resulting in high shear failure from slower acceleration than the ground, again a weight distribution problem. The reaction is to put the structure in bending which causes tensile cracks on the surface or internally, and compression on the opposing surfaces. The cracks then propagate and can cause ultimate failure of the building. Most often it starts at the roof where the bending loads are highest due to weight by improper designs, collapsing the roof objects that cause injury, secondarily the upper walls fail. The same effect happens in tornadoes that incorporates concrete walls and wood or metal roofs not tied down well although a different reaction.

3. Shock isolation is another issue, most of CA has been rebuilt to isolate structure. Strawbale has isolation attributes.

4. In severe S_ZONES, an alternate redundant continuous load path is needed. This becomes the primary load carrying structure that acts to resist in plane and out-of-plane(bending) or shear loads. A continuous structural grid of the foundation, walls, bond beam, reacts the acceleration forces in 3 dimensions and provides the most robust loads paths. The COB or brick becomes secondary structure not "in-fill"...it's load carrying capability s/b used to reduce the primary structure sizing and weight ideally of higher strength-to-weight ratio especially at the upper portions of the building.

5. Core samples s/b analyzed in a lab prior to build and the mix ratios inspected at the build to assure quality and consistent density for uniform loading.

Here is a video on adobe brick earthquake resistant construction There is another video I cant seem to find but it was the same idea except there was a buttress every 3 meters or so.

I would also like to point out that the shape (of the home), indoor lay out (spacing of of indoor walls) , amount of openings in a wall run as a ratio of those openings to the entire walls length, how far from the corners those openings are, wall height to width ratio's and wall lengths to buttressing are all factors in building an earthen home that I very seldom hear anyone talk about when building earthquake resistant homes out of said material, let alone builders actually implementing said techniques.

I cringe when I see a window or door way within 5 feet of a corner wall or a 30 foot wall length with half of it being a huge glass wall and the rest adobe brick. http://inhabitat.com/minimalist-adobe-brick-home-is-a-box-within-a-box/new-9-3/ obviously, but I guess not so obvious to the designer, architect, or builder, the right corner wall will be the first place to fail in a tectonic event. http://lesteves.wikispaces.com/An+authentic+adobe+brick+home another failure waiting to happen not mention the walls height to width ratio is VERY questionable but would guess it is inadequate. http://dogsinvalpariso.blogspot.com/

It was built using the “bookshelf” technique – placing small rectangular adobe bricks (6 million of them) vertically leaving a space between, and putting plaster only on the upper and lower parts. This provided enough give to absorb centuries of shocks.

in the second or so pick this building technique prevents wall collapse by having each brick "isolated?" which allows them to move in tectonic events without the wall falling? It was also built in a pyramid form which has added to its earthquake durability.