Rima Taher, an expert in the design of low-rise buildings for extreme winds and hurricane, hopes her phone won't ring much this hurricane season. It's already been busy with requests for information about best building design and construction practices to reduce wind pressures on building surfaces.
In the aftermath of the January earthquake in Haiti, Taher, a civil and structural engineer at the NJIT College of Architecture and Design, prepared a document for Architecture for Humanity http://architectureforhumanity.org/about about best building practices for hurricane and earthquake-prone areas. It's posted on the organization's Haiti Reconstruction website and still circulates in Haiti. More recently, she cooperated with wind researchers at Tokyo Polytechnic University, Japan, to develop and translate from French a brochure for UNESCO to help Haitians prepare for the upcoming hurricane season. UNESCO will distribute the brochure in Haiti.
In 2007 Taher's article about the design of low-rise buildings for extreme wind events appeared in the Journal of Architectural Engineering of the American Society of Civil Engineers. Another article on improved building practices for hurricanes appeared in Caribbean Construction Magazine in July of 2009.
"Certain home shapes and roof types can make a big difference," is a common refrain in all her work.
Her recommendations include the following.
Design buildings with square, hexagonal or even octagonal floor plans with roofs of multiple slopes such as a four-sloped hip roof. These roofs perform better under wind forces than the gable roofs with two slopes. Gable roofs are common only because they are cheaper to build. Research and testing demonstrate that a 30-degree roof slope will have the best results.
Wind forces on a roof tend to uplift it. "This explains why roofs blow off during extreme wind events," Taher said. To combat uplift, she advises connecting roofs to walls strongly with nails, not staples. Stapled roofs were banned in Florida after Hurricane Andrew. The use of hurricane clips is recommended. The choice of roofing is important. Different roofing systems perform differently under hurricane conditions. In tile roofs, loose tiles often become wind-borne debris threatening other structures.
Aim for strong connections between the structure and foundation. Structural failure-- one structural element triggering the collapse of another—can be progressive.
Hurricane shutters can protect glazing from wind-borne debris. Various designs are available.
Roof overhangs are subject to wind uplift forces which could trigger a roof failure. In the design of the hurricane-resistant home, the length of these overhangs should be limited to about 20 inches.
The design of the researched cyclonic home includes simple systems to reduce the local wind stresses at the roof's lower edges such as a notched frieze or a horizontal grid. Install the latter at the level of the gutters along the homes' perimeter.
An elevated structure on an open foundation reduces the risk of damage from flooding and storm-driven water. All foundation piles must be strengthened by bracing and should penetrate deep enough into the soil to reduce the risk of scour.
NJIT, New Jersey's science and technology university, at the edge in knowledge, enrolls more than 8,400 students in bachelor's, master's and doctoral degrees in 92 degree programs offered by six colleges: Newark College of Engineering, College of Architecture and Design, College of Science and Liberal Arts, School of Management, Albert Dorman Honors College and College of Computing Sciences. NJIT is renowned for expertise in architecture, applied mathematics, wireless communications and networking, solar physics, advanced engineered particulate materials, nanotechnology, neural engineering and e-learning. In 2009, Princeton Review named NJIT among the nation's top 25 campuses for technology and among the top 150 for best value. U.S. News & World Report's 2008 Annual Guide to America's Best Colleges ranked NJIT in the top tier of national research universities.
ATTENTION EDITORS: To interview Taher, call Sheryl Weinstein at 973-596-3436 or contact Taher directly at 973-340-9095
Sheryl Weinstein | EurekAlert!
Smart buildings through innovative membrane roofs and façades
31.08.2017 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP
Concrete from wood
05.07.2017 | Schweizerischer Nationalfonds SNF
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
13.12.2017 | Health and Medicine
13.12.2017 | Physics and Astronomy
13.12.2017 | Life Sciences