Guest Blogger – The Benefits of Multi-Hazard Engineering

Hurricane Katrina and the Indian Ocean Tsunami are among the most serious and devastating natural disasters in recent history. They are both known worldwide for the many lives lost and the extreme property damage that resulted. Hurricane Katrina struck the Gulf Coast in 2005, primarily hitting Louisiana, Mississippi, and Alabama. Hurricane Katrina was a Category 3 hurricane when it made landfall and was the costliest hurricane in the history of the United States, causing $81.2 billion in damage. New Orleans was among the cities to be hit the hardest, as protective levees broke and much of the city flooded. Storm surge wave heights exceeded twenty feet and flooded 80% of the city. The Gulf Coast of Mississippi was equally devastated by storm surge and wave action as well as winds. The Indian Ocean, or Boxing Day, Tsunami occurred on December 26, 2004, originating off the northwest coast of Sumatra, Indonesia. Its destructive effects were felt across the Indian Ocean and all the way to the eastern coast of Africa. The tsunami resulted from a magnitude 9.2 subduction earthquake. The waves propagated from the epicenter of the earthquake and caused the most damage in Indonesia, Thailand, Sri Lanka, and India. Wave heights exceeded 10 meters and reached several kilometers inland in Thailand, as shown below by the markers placed along the coast in Phuket. It is estimated that 230,000 people were killed as a result of the tsunami, in part because of the absence of a warning system. The tsunami was especially devastating in small Asian fishing villages that were built along the coast. Not only did these disasters cause immediate destruction, but for some areas much of the devastation remains today, as shown in the image above, taken two years after the Indian Ocean Tsunami.

Hurricane Katrina and the Indian Ocean Tsunami remain pivotal events in my life due to personal experiences with the resulting devastation. I had the opportunity to visit New Orleans after Hurricane Katrina with my Computational Methods class at the University of Notre Dame to study the levee system and its failure. I was also involved in forensic engineering research that used satellite imagery and aerial photography to investigate the causes of damage to structures near the coast in Mississippi. In addition, I participated in a Research Experience for Undergraduates (REU) program, Interdisciplinary Studies in Tsunami Impacts and Mitigation (ISTIM), at the University of Notre Dame during the Summer of 2007. As part of this program, we traveled to Phuket, Thailand to see first-hand the devastation caused by the tsunami and learn how to better design and build structures to prevent future deaths and destruction from similar disasters. While the occurrence of these hazards is beyond our control, novel structural engineering approaches have the ability to reduce their consequences.

It became apparent during these site visits and research experiences that structures in these areas are affected by multiple hazards, leading to unexpected effects. For example, many structures close to the coast in the southeastern United States are not only affected by the strong winds associated with a hurricane but also the damaging effects of storm surge and waves. This can be seen in the images below, taken after Hurricane Katrina, which show complete destruction of homes due storm surge and waves (left) in close proximity to homes that suffered minor wind damage but were elevated from the storm surge (right). In addition, the Indian Ocean Tsunami showed that structures near the coast in strong seismic areas may be affected by both earthquakes and tsunamis. And finally, the 2010 Haiti Earthquake occurred in an area typically affected by hurricanes. Therefore, most structures are not vulnerable to one single hazard and managing hazards individually may not yield the most efficient and effective designs. In addition, the most extreme load conditions, two hazards acting together, may not be considered.

These and similar observations are what generated the relatively new area of multi-hazard engineering. Multi-hazard engineering aims to use available resources most effectively to design safe structures that are able to withstand a range of natural hazards. This approach involves an understanding of all of the hazards that could potentially affect a structure and the use of this knowledge to determine which aspects of the structure may be most vulnerable. Then, robust design features can be incorporated in order to enhance performance when considering individual hazards or the combined loading from several hazards. Post-disaster site visits and satellite imagery are invaluable to the determination of these robust design features. For example, the building shown below is in the region hit by the 2004 Indian Ocean Tsunami. The lower level of the structure bore the brunt of the damage. The walls perpendicular to the wave direction have been completely destroyed. The structure, however, remained standing. After the perpendicular walls were broken, the water was able to flow through the first floor diminishing the overall loads on the structure. Post-disaster photography, such as this, can help in determining better design practices for the future. Breakaway walls on the lower levels of structures in tsunami-prone regions would allow the water to flow through instead of causing a build-up in the pressure and the forces on the ocean-side wall and other foundation components.

POST-INDIAN OCEAN DAMAGE IN ACEH, SUMATRA, INDONESIA (DEPARTMENT OF DEFENSE PHOTO—MICHAEL L. BAK)

Designing low income urban housing comes with its own set of unique challenges without consideration of the multiple hazards with which the structures may be faced. A multi-hazard approach, however, can readily be incorporated into the design stages in order to ensure that the resources that are available are being used to most effectively resist the hazards. It is envisaged that a strong, multi-faceted structural system promises to mitigate damage from many hazards. Structural engineers have the unique ability to positively influence society in an important way by improving the resiliency of structures to hazards, allowing people all over the world to have access to safe structures in which to live and work, Shelters For All!

– Megan McCullough, Civil Engineering Graduate Student, NatHaz Modeling Laboratory, Department of Civil Engineering and Geological Sciences, University of Notre Dame

Guest Blogger: Protecting Coastal Villages in the Developing World

On December 26th, 2004 the Indian Ocean tsunami caused devastation in fourteen countries including Indonesia, Sri Lanka, India, and Thailand.  Nearly two and half years later in the summer of 2007 I was doing research on sustainable structural design to resist natural hazards through a National Science Foundation program at the University of Notre Dame, which ended with a field study in Thailand.  Little did I know that this trip would be an eye-opening experience that would forever change my life.

I didn’t realize the need for sustainable housing in the developing world until I witnessed it first hand.  I was shocked to see that two years after the horrific event, communities in Phuket and Khoa Lak, Thailand were still in shambles.  Walls had been ripped out of houses leaving only the structural frames.  The remains of buildings were filled with debris of all sorts, and structural beams were bent and deformed beyond repair.  (See photos below).

Photo by Mary Beth Oshnack

Photo by Mary Beth Oshnack

Photo by Mary Beth Oshnack

While it was encouraging that reconstruction had begun in some villages, (see more photos) it saddened me to see buildings being constructed in the exact same areas where others were destroyed. Were these new structures destined to be subject to the same fate as their predecessors in the wake of another disaster?  For larger commercial structures like hotels, developers are willing to build closer to the shoreline and therefore risk being inundated in order to promote tourism and enable the guests to enjoy the natural beauty of the ocean.  It helps that these hotel chains can afford to rebuild after a structure is lost. But what is the solution for fishing communities who have to be near the sea to sustain their source of livelihood?  Can we provide shelters to help them live safely in the event of a natural disaster?

Photo by Mary Beth Oshnack

My trip to Thailand encouraged me to continue my research on tsunami inundation.  While as a graduate student at Oregon State University, I found that small seawalls cause a skyward deflection of incoming tsunami waves that dissipates energy, reducing the force on landward structures.  More on this research can be found here.

Discovering the degree to which a design concept like small seawalls could help entire communities in the wake of a disaster was a really rewarding experience for me.  I used my knowledge, experience, and passion for the subject to help find a solution to a problem that I genuinely cared about. And now I’m asking you to do the same! Let’s find a way to make affordable yet durable housing available in areas where materials are scare and challenges like growing populations and the threat of natural disasters are eminent.  Let’s find shelters for all!

– Mary Beth Oshnack, Senior Engineer in Training, GAI Consultants Inc. (Pittsburgh, PA)

Guest Blogger – A REAL Picture of Brazil’s Favelas

Image

It’s easy for us gringos to glamorize the favelas, which are the slums of Brazil.  They are portrayed in films and photos nestled on scenic hills with breathtaking views overlooking the beaches and abundant natural beauty that the country offers.  Despite the fortunate favelas where this is true, the reality is that the overwhelming majority of favelas bear no resemblance to the photo above or the famous Rio de Janeiro locations portrayed in films.  The photo below is a more accurate depiction of the current state of living environments that are made available to low-income Brazilians.

 

 

Like most of the slums around the world, the favelas are occupied by the individuals and families who are the unfortunate byproducts of their country’s failure to provide affordable housing options for its people.  This major lack of proper infrastructure forces people to move to squatting areas.  In this situation, it doesn’t matter what the education or income level of the residents are, if people are forced to build their own homes with no guidance or codes, it will create a living environment that is unfit and unnecessary by today’s standard of living.  This practice essentially wipes away hundreds of years of living environment improvements that have been continuously updated throughout the years.

The birth of the favelas began when mass immigration from Europe created a housing shortage in the city centers.  In order to combat this problem, the government enacted programs to push out the lower income residents to designated spaces at the city’s edges.  Once there, the government took an “out of sight, out of mind” approach to overseeing the development of these communities.  Without any building code enforcement and without basic proper sanitary infrastructure provided by the government, it was inevitable that these communities would spiral out of control to form a sub-standard living environment.  Fast forward 3-7 decades later, and these problems are still being unaddressed, as most favelas have no government representation and are provided with little to no municipal assistance.  In some favelas in the large cities, it is not uncommon for the residents to be dependent on drug lords to provide the most basic services.

Due to the explanations given above and combined with overcrowding, environmental and sanitary issues are of extreme importance in the favelas.  Individual housing units lack plumbing systems, water supply, and proper electricity connections.  Waste collection is also insufficient or in some cases non-existent.  Communal washing areas consist of tubs and buckets of cold water.  Electricity is stolen from any possible source which leads to the extremely unsafe practice of linking hundreds of housing units to one power source in a very crude and haphazard manner.  Even the basic system of mail delivery is virtually impossible.  The majority of building materials used in favela living spaces is that of previously discarded items that were collected and used in makeshift construction, which can include metal sheathing used for roofing and walls.

You can be the one to develop a better housing strategy for those in need in Brazil — visit sheltersforall.org.

– Jeff Loftus, Structural Engineer, B.S. Lehigh University 2007, M.E. University of Southern California 2010

 

Focus on What’s Important – Haiti Photos, January 14, 2010

Photo from National Geographic

Today we’re going to look back at the images of Haiti immediately after the magnitude 7 earthquake that struck nearly 2 years ago.

Photo from the National Geographic

Photo from National Geographic

There is a real need for sustainable, safe housing. You can be the one to change the future of places like Haiti. Join the challenge at sheltersforall.org.

Guest Blogger – Choose Your Own Adventure: The Role of Choice in Housing

Photo by Dustin Mix

I was talking to a friend a few days ago about the book series from grade school called Choose Your Own Adventure. If you don’t remember or aren’t familiar with these books, they were the type where you read a chapter and at the end, based on what you had gathered to that point, would be faced with making a decision on the protagonist’s next action. Based on your choice, you’d be directed to another section of the book and repeat the process until the story was resolved. Books had multiple endings based on the decisions you made, ranging from finding treasure to being defeated by “evil” forces. For us control freaks, these books were addicting. No longer was reading a book a passive, purely observational exercise, but now I could have some sort of influence on the story. I would read these books intensely, combing for the slightest of hints in each chapter as to what decision I should make next and obsessing over getting to the best possible ending. The satisfaction of getting to that ending was such a different feeling than reading a traditional fictional book. The power of transferring the choice of how the story would end from the author to the reader was liberating, addicting, and at times even frustrating. But the ability to direct the story was what drew me in.

In many ways, the urban housing problem in developing countries is a result of a disregard for the theme of Choose Your Own Adventure books. Across the globe, people are born into circumstances that set them up for a life riddled with a lack of choice. Whether it is choice hindered by economics, education, geography, discrimination, or a host of other factors, the world’s poorest often have been at the mercy of decisions and institutions in which they have no voice. Solving the problem of substandard housing in urban slums across the globe is a complicated and dynamic undertaking. However, the basis for any such solution should be the provision of choice; an act of empowerment. Human beings have no inherent desire to live in the squalor and inhumane conditions that define slums. Given the ability to choose between a safe or dangerous home, people will choose safety. Given the ability to choose between sanitary waste systems or an open latrine, people will choose sanitation. Given the ability to protect their families or be exposed to the elements, people will choose protection. The choice to live in a safe and clean environment and to provide shelter for one’s family is human instinct. Having that choice, having the power over the state of one’s situation, is at the core of what it means to have dignity. This dignity, inherent to existing as a human being, is to have access to the things it takes to survive in this world, however dynamic those things may be.

Photo By Dustin Mix

“Housing the world’s poor” is an often used phrase in the discussion of urban slums. If the urban slum problem is going to be addressed, the phrase needs to be more of a result than an action. Empowerment and choice is where the solution lies. Shaping and crafting an environment in which people have the choice and power to influence their living conditions is the most critical engineering task the world faces in addressing this problem. The problem is much bigger and more complex than simply providing a roof to live under. Housing is an indicator of so much more than just the availability of building materials or construction expertise. Housing is a measure and outward illustration of quality of life. The goal of improving the living conditions of the 1 billion people that are currently living in substandard conditions will manifest itself through that indicator.

Photo by Dustin Mix

Choose Your Own Adventure books didn’t always turn out the way I wanted. But as frustrating as it was to admit, I was always responsible for how I got to each ending, through the choices I had made. There won’t always be happy endings, but building systems that allow people the chance to reach a favorable ending is an adventure we all should choose.

Dustin Mix, Structural Engineering Graduate Student at the University of Notre Dame

Contemporary Earth Construction

Earthen House in Thailand - Photo by Amanda Kovattana

A recent article from The Built and Human Environment Review suggests there are misconceptions about the usefulness of earth housing.

The authors outline the primary problem: unsustainable and unaffordable materials – “A house is composed of several materials such as brick, cement, timber, window frames and several other building materials and the use of bricks as a standard building material began in the early 1900s in most of the African countries. Brick, cement, sand and timber are the major construction materials in Africa up to date which is unaffordable nowadays and an appropriate building material and construction technique needs to devise to solve the urban housing crisis (Zami, 2010)” (p. 86).

The authors suggest taking a closer look at earth construction, outlining examples from Africa and the Middle East. However, before construction takes place, a proper examination of the soil is required – “The identification process involves various tests, which need the use of a laboratory. Apart from the laboratory identification process, local knowledge of the soil and traditional skills are necessary” (p. 87).

The authors then outline some contemporary uses of earth construction in Zimbabwe, Sudan, Kenya, South Africa, Angola, and Mali.

They conclude, “Earth is affordable and available and would be appropriate in the case of low cost house construction in many African countries…  The only challenge that prevents earth becoming the preferred choice of building material amongst the professionals, politicians, decision makers and the clients is acceptability. An awareness and understanding by people to environmental issues such as air pollution, deforestation, land degradation and energy conservation would help them change their attitudes and views towards earth building. The flexibility and simplicity in technology incorporated in earth building affords adaptability and easy transfer of knowledge between different stakeholders in the building industry. Individuals and community as a whole can easily participate in building their own homes in affordable ways.”

What do you think – is earth housing the future of the urban housing crisis? Submit your proposal at sheltersforall.org.

Kenya Railways Update Leads to New Housing

File Photo from the Business Daily Africa

In Kenya, an update to the railway system provides for the relocation of thousands of people to protect their safety. Because of the location of the train — only a few meters from the nearby dwellings — the trains must slow to a creeping speed to protect the people living nearby.

The Kenya Railways upgrade includes the creation of 3,129 single-roomed houses, 1490 of which will include a kitchen, sleeping area, and toilet on the upper floor and trading stalls below. The units will be connected to water and power.

Check out the article here. If you have another great idea for sustainable urban housing, consider submitting the proposal for a chance at over $15,000 (USD) in prizes at http://sheltersforall.org/.