Here's an article that speaks to the point of construction type for hurricane resistance.
Original Message:
Sent: 10-14-2018 13:03
From: Raul Hinojosa
Subject: Hurricane Michael – Hope the Last One of the 2018 Hurricane Season
Well said @Ramses Sanchez . I've grown and raised in the Caribbean as well like you (Dominican Republic), and despite being a third world country it is clear that Reinforced Concrete is the way to go. Personally the Eye of Hurricane George CAT 4 almost CAT 5 pass by my town and absolutely nothing happen to my house.
I understand the lobbism of the wood industry in the U.S. but seems like we as engineers are looking for an excuse to make wood construction better instead of cut to the chase and use concrete for everything, not only the foundation but walls, floors and more importantly the ROOF.
The technology is there to analyze and design any type of concrete construction and the materials as well. Now it is doable and aesthetic is not a problem, because you can do concrete roofs any shape, pitch, form, in fact the more folded the better. A monolithic structure is the solution. I have been doing hundreds of those concrete roofs and concrete shell structures structural designs in the U.S. for various residences and affordable housing as well and it is possible and the ROI is very fast, sometimes less than 5 years and after that it's all savings. Really there is not an excuse, it is up to us to move ahead and lead by example, the solutions are out there waving at us since a long time ago.
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Raul Hinojosa Ing., M.ASCE
Structural Engineer
Miami/Orlando FL
Original Message:
Sent: 10-13-2018 08:50
From: Ramses Sanchez
Subject: Hurricane Michael – Hope the Last One of the 2018 Hurricane Season
In my lifetime I had lived through five major hurricanes since the 60's, including Andrews (1992) when living and working in South Florida. The 90's was a specially active decade in Hurricanes for Florida, and I remember discussing with friends and colleagues the house construction systems, specially in a time when great homes communities were being developed.
Being a Caribbean native (D.R.), I knew for experience, and then as a practicing structural engineer, that houses built with wood, and mostly, roofs made out of weak nailed trusses with equally nailed plywood diaphragms did not have a chance against a CAT-3 or above hurricane. Sometimes even a CAT-2 could do great damage. I remember clearly Andrews devastation in Homestead (South of Miami), I lived at what it seemed to be at the time the "north street border" of the biggest destruction, in the only three (3) story concrete condo of the area. We went harmless. Everything else around was flatted.
My major surprise was when they started re-building exactly the same way the obliterated houses were built before. And again, and again and again, to these days. Back in the time I recall that after a lot of of discussions, meetings, and "studies" for a Construction Code reform, the greatest results were throwing in a few extra steel plates and bolts. And forbidding the use of the infamous staples frequently used also for... attaching roof diaphragms!!
I still don't understand (well, I have a pretty close idea) why they insists on this construction method. Same for the central states where they suffer tornadoes, sometimes worst, because they form suddenly without much time for preventive measures like hurricanes, that can be tracked for days, even weeks. It's hard for me to think on economics reasons in a country like U.S.
In my country, where I actually live and practice, upon returning many years ago already, nobody even considers or whatsoever building a house (or anything important for that matter) with structural wood. At the most you can have small secondary, constructions -open, most of them- like gazebos, canopies, architectural decorative attachments, or backyard shacks for home leisure. But always conscious that in face of a hurricane those structures will fly.
It is my opinion that the State of Florida should have a serious discussion about home building codes. Wood studs second floor exterior load bearing walls, wood trusses/rafters and nailed (or worst, stapled) plywood diaphragms will have little or no chance at all against 90+ MPH sustained winds. No matter what our nice and elegant computer (or hand, if you like) calculations say. RC, CMU, steel and rigid diaphragms are the best materials at hand (so far, of course) to protect lives and homes, specially in places like Florida where there is no seismic threat, and wind it's their only concern.
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Ramses Sanchez Aff.M.ASCE
Structural Engineer
Santo Domingo, Dominican Republic
Original Message:
Sent: 10-11-2018 13:25
From: Dilip Barua
Subject: Hurricane Michael – Hope the Last One of the 2018 Hurricane Season
Just within about 3 weeks time – a different experience and perspective – not only in the locations of landfall, but also in the characteristics of two different hurricanes. While the September 13th Hurricane Florence was like a nasty sluggish monster – yesterday's Hurricane Michael was like a heroic monster in its wind power and storm surge. The former showed the power of relentless rainfall poured by a weak crawling storm. The latter is an example of the power of very high sustained wind speed of a fast-moving hurricane – let us say, in its grandeur like the utterance of Julius Caesar: Veni Vidi Vici.
We can describe both the storms in all different attractive terms in an attempt to make a serious subject lighter – but the misery of the affected people, damages and destruction are very real and painful. We feel their pain deeply and our thoughts and prayers are for the victims. Fortunately for the Florida Panhandle region however, the piling of storm surge by the landfalling (October 10th, 13:30 ET) Hurricane Michael came about 2 hours before the high tide (at about 15:10 ET at Apalachicola). This time-difference has likely abated the peak surge somewhat – yet strong enough to cause extensive coastal flooding with the surge force uplifting and carrying boats, homes, cars and debris like toys.
We will know more about the trail of destructions inflicted by Hurricane Michael in its trajectory in the coming days. It will be interesting – and we invite all to share insights and experiences of this latest monster near the end of hurricane season.
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Dr. Dilip Barua, Ph.D, P.Eng, M. ASCE
Vancouver, BC, Canada
Website: https://widecanvas.weebly.com
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