Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NJIT professor says certain home shapes and roofs hold up best in hurricane

20.06.2007
Certain home shapes and roof types can better resist high winds and hurricanes, according to a researcher at New Jersey Institute of Technology (NJIT).

Civil engineer Rima Taher, PhD, special lecturer in the New Jersey School of Architecture at NJIT, spent two years examining the findings of research centers that have studied the best designs and construction materials and methods needed to withstand extreme wind events and hurricanes.

“Although I’d like to say that there is a simple and economical solution for housing that won’t fail or collapse in the perfect storm, such information does not yet exist,” said Taher. “However, it is obvious that thanks to the work of wind engineers and researchers that changes to home design and construction can make buildings safer for people, while saving government and industry billions of dollars annually.”

“Design of Low-Rise Buildings for Extreme Wind Events” (Journal of Architectural Engineering, March, 2007) by Taher highlighted such research findings. Wind researchers at the Center for Building Science and Technology (CSTB) in France, researched and tested reduced-scale home models at its wind tunnel facilities, and developed a prototype of a “cyclonic” or hurricane-resistant dwelling. Taher cooperated with the CSTB wind researchers, working on the structural aspect of the home’s design.

That design eventually became an elevated structure of a square plan form on an open foundation. The home had a hip roof and was equipped with a central shaft with aerodynamic features designed to reduce wind forces during an extreme wind event. Wind tunnel tests at CSTB showed that such a home would be far more efficient under high winds and hurricane conditions than a typical structure. CSTB is working with a builder to construct a prototype of such a home on Réunion in the West Indian Ocean.

From this work and other studies Taher recommends the following construction considerations for homeowners in hurricane-prone regions.

A home with a square floor plan (or better a hexagonal or octagonal plan) with a multiple-panel roof (4 or more panels) was found to have reduced wind loads.

Roofs with multiple slopes such as a hip roof (4 slopes) perform better under wind forces than gable roofs (2 slopes). Gable roofs are generally more common because they are cheaper to build. A 30-degree roof slope has the best results.

Wind forces on a roof tend to be uplift forces. This explains why roofs are often blown off during an extreme wind event. Connecting roofs to walls matters. Stapled roofs were banned following Hurricane Andrew in Florida in 1993.

Strong connections between the structure and its foundation and connections between walls are good. Structural failure is often progressive where the failure of one structural element triggers the failure of another, leading to a total collapse. Connections are generally vulnerable but can be inexpensively strengthened.

Certain areas of a building such as the ridge of a roof, corners and eaves are normally subject to higher wind pressures. In the cyclonic home design, CSTB researchers proposed some aerodynamic features to alleviate these local pressures such as introducing a central shaft which would function by creating a connection between the internal space and the roof ridge considered to be the location of the largest depression. This connection helps balance pressures leading to a significant reduction in the roof’s wind loads.

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 20 inches.

The design of the 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 to be installed at the level of the gutters along the perimeter of the home.

An elevated structure on an open foundation reduces the risk of damage from flooding and storm-driven water.

Sheryl Weinstein | EurekAlert!
Further information:
http://www.njit.edu

More articles from Architecture and Construction:

nachricht Concrete from wood
05.07.2017 | Schweizerischer Nationalfonds SNF

nachricht Modular storage tank for tight spaces
16.03.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

All articles from Architecture and Construction >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Gold shines through properties of nano biosensors

17.08.2017 | Physics and Astronomy

Greenland ice flow likely to speed up: New data assert glaciers move over sediment, which gets more slippery as it gets wetter

17.08.2017 | Earth Sciences

Mars 2020 mission to use smart methods to seek signs of past life

17.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>