Reconstruct with Bamboo
Behavior in earthquakes or hurricanes
In case of a dynamic overload, as it occurs in earthquakes and hurricanes, following reactions can be realized: Statistically steel fails before concrete does and if steel failed long ago and 80 percent of the concrete constructions collapsed, then only 10 percent of the constructions of bamboo and wood would fail, see diagram!
Another advantage of bamboo, which is not taken into account in the statistical consideration before, is the absorption of energy in the joints. At excessive load, about 85 percent of the energy is used for the deformation of the joints, and only 15 percent cause elastic bending of the material.
Bamboo keeps helping after the earthquake, too!
As the forests are in peril in Indonesia, the villagers are poor, Giant Bamboo is the answer all the way around. It is the strongest most flexible material for building in a earthquake zone, it can grow more than a metre a day, new shoots can be started by cuttings, it makes a terrific barrier against wind and possibly, wild pigs and tsunamis (like the mangrove forests).
I have contacted Paul Wandera at Bamboo Kenya (click on title link) to see if I can hook him up with IDEP, Howu-Howu, SAI, and Surfzone Relief.
Bali is a major consumer and user of Bamboo, and IDEP is based there. I am hoping we can get some shipments of cured giant bamboo for building started for the villages, as well as the delivery of cuttings so they can start to grow it. Birdie (see below for more from Paul's site)
Bamboo is many things to many people.
It is apparent that the bamboo can play an important role in the development of the country’s economy and especially the rural economy by generating entrepreneurship and employment. The potential has however not been recognized.
WHO WE ARE
Bamboo Kenya was founded by, Paul Wandera an architectural technician and bamboo enthusiast. We are eager to share what we know, to educate and teach people about bamboo. Bamboo Kenya has visions and ambitions for the broadened use of bamboo in Kenya looking for sustainability and visibility. We want to focus our energy solely upon finding a solution to, environmental concerns regarding the diminishing forest resources in Kenya and to inform people about bamboo as an environmentally renewable non-wood forest resource. Apart from this Bamboo Kenya would like to start informative educational programs on bamboo that will protect tropical forests by promoting and demonstrating the many conservation and development opportunities that bamboo offers. We will strive to promote the use of bamboo and educate others about the greatly misunderstood and underutilized benefits of using and preserving this plant. One of the main ways in which we hope to accomplish this is through our educational and our consultant services and by your continued participation and support.
Bamboo is a survivor it bends but it doesn’t break.
posted by birdieee at Friday, April 15, 2005
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The Role of Technology in Earthquake Hazard Reduction and Land-use Planning
Beth Olsen
A shift in research strategies is occurring. University-based programs are moving from a theoretical and discipline-specific emphasis to an interdisciplinary problem-solving orientation (1). One of the best examples of applied technology using this interdisciplinary approach can be found in projects focussing on the use of salt-treated bamboo as an earthquake-resistant building material (10,11). Bamboo is a genus of plants indigenous to Asia and Africa. It has been used as a building material in these regions since prehistoric times and its use is an integral part of indigenous cultures.
Bamboo is gaining in popularity as an earthquake-mitigating material largely because engineers are beginning to understand its structural properties. Bamboo grows in the greatest abundance in the earth's subtropical and tropical zones. (10) This is where the majority of earthquake hazards occur, most of which are in LDC (1). New research is investigating the use of bamboo in engineering inexpensive, earthquake-resistant structures. The jointed stalks, culms, of the plant are extremely flexible and have superior weight-bearing capacity. (10,11) For example, the compression strength of Guadua angustifolia, a species used in the University of Costa Rica (UCR)’s National Bamboo Project (CRNBP), is 500 kilograms per square centimeter, nearly twice that of concrete (10). Little energy is needed for the production of bamboo, especially when viewed with respect to the bearing capacity of the material (11).
UCR structural engineers (10) in cooperation with the Department of Building and Architecture at Eindhoven University of Technology in the Netherlands (11) designed and constructed 30 low-income housing units in an earthquake-prone region of Costa Rica. They first erected a frame of thick bamboo poles and then draped the structure with a woven mesh of split bamboo covered with mortar. The bamboo provided the support. The mortar provided the strength. In 1994, the structures were at the epicenter of a 6.7-Richter magnitude earthquake. The bamboo structures, the only buildings left standing near the epicenter, survived without so much as a crack. Since the quake, the CRNBP built 670 three-bedroom, 480-square-foot units costing about $4,500 (1997 U.S. dollars) apiece. The project has met with such success that planners now intend to construct 1,000 homes per year. The Indonesian Island of Flores is substituting flexible bamboo structures for thousands of wood and cement-block homes destroyed in a 1992 earthquake. The use of bamboo in larger buildings has been limited by a lack of knowledge in making weight-bearing joints out of hollow tubes. In most bamboo housing, the tubular frames are lashed together with strips of bamboo. Although suitable for small houses, the technique is not stable enough for larger weight-bearing structures. The CRNBP is currently testing new techniques for joint design. Commercial adhesives, straps, and pneumatic nailing can join small boards sawed from bamboo. Bolting plates to the culms or binding them with wires put through small-diameter holes can join hollow bamboo logs. Bamboo can thereby be used in trusses in large buildings such as meeting halls, gymnasiums, and churches, projects that bamboo officials in Costa Rica and elsewhere anticipate will be constructed soon. (10)
With computer-generated models now used extensively to simulate components of an earthquake, the complexity of the problems investigated have increased (1). We need to concentrate on improving our technology-transfer mechanisms. There remains a large gap in communication between researchers and practitioners and between MDC and LDC. As an example, one peer-reviewed article I encountered introduced the reader to the acronyms CPT, SPT, and NCEER without explanation of their meaning. CPT and SPT were eventually defined two pages into the report. NCEER was never defined. (15) This makes the paper very difficult to understand for those outside the specialized field in which the authors are engaged, a clear communication breakdown between these engineers and the practitioners who need the information. I recommend that in the U.S., government-subsidized studies include in their contracts a requirement for the use of the least complex language in written reports. Where jargon serves the purpose of communicating very specific ideas for which there are no equivalent words in common usage, a definition of terms should be required as an appendix. Presently some states, Pennsylvania is one example, have laws in effect that restrict the unnecessary use of complex language in legal contracts. If a lawyer writes a contract of any kind that uses more complex language than is necessary to make a point, the contract is null and void. A similar mechanism could be used to reduce unnecessary jargon in scientific reports. Government reimbursement for a study could be linked to the use of common language in the report. As part of the peer-review process, the scientific community could self-police by rejecting reports that use unnecessarily complex language.
Another recommendation I have is to increase funding for real-situation testing of engineering that has been modeled successfully. Sites where seismic activity is greatest and other conditions are similar to those in the model would be ideal for testing the new concepts. The CRNBP is an excellent example of this strategy.
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