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RE: I Agree with Fred ![Subject Prev][Subject Next][Thread Prev][Thread Next]
- To: <seaoc(--nospam--at)seaoc.org>
- Subject: RE: I Agree with Fred !
- From: "Dennis S. Wish" <wish(--nospam--at)cwia.com>
- Date: Thu, 28 May 1998 21:04:25 -0700
Bill Allen has suggested I provide a few figures in lieu (no pun) of my promise to stay off this topic. Shortly after Northridge, a seminar was held to discuss the findings of a Ad-hoc committee's joint task force of SEAOC and the City of Los Angeles for Wood Framed Construction. One segment of the seminar was entitled "Wood-Framed Multi-Unit Residential" and was presented by Ben Schmidt SE. The purpose of the Task Force findings were to make recommendations for action. Schmidt studied a 125 unit apartment building damaged in the Northridge earthquake. His report includes a survey of the damage as well as supporting calculations to verify the modes of failure. In a letter to Prof. Wilfred Iwan of Cal Tech, Paul Fratessa and Frank McClure of the Seismic Safety Commission, Ben Schmidt stated "We can all agree that 90% of all buildings constructed in California are wood frame. The Northridge Earthquake again exposed, to knowledgeable Structural Engineers, the poor performance and loss of occupancy of an unreasonable number of housing units.." He pointed to economic concerns and some life safety issues. Item #3 in Bens report state: " Pages 1 through 17 describe a study currently underway by this office for Nabih Youssef for the Owners of a large number of existing Apartment Complexes 10 to 20 years old, in Orange County. A cursory review of the plans and filed observation showed that some life safety problems are evident. Namely, the apartment units with tuck-under parking that are laterally stayed only with drywall or stucco along the center-line of the building, similar in configuration to the failed Northridge Meadows Buildings.".. In conclusion, Ben stated "If the Seismic Safety Commission does not face the above issues and work toward solutions, then the Commission will have negated its reason for being. The Commission must face the fact that over 30% of all existing wood frame structures in California are grossly deficient." In the same seminar, James Russell CE presented "Unstiffened Cripple Walls / Flatland Dwellings" in which he concludes "Presently the total number of buildings within the City of Los Angeles is included in the scope of the proposed residential strengthening provisions is unknown, but could exceed 100,000. Based on the field investigation observations of the subcommittee, the most vulnerable buildings (not including hillside homes) are those using horizontal wood siding or stucco as the cripple wall bracing materials and those without sill plate anchorage. Locating and inventorying buildings with these characteristics would be necessary to determine the true scale of a mandatory retrofit program." The city of Los Angeles, in response to the new state disclosure act (AB200) instituted voluntary measures consisting of a prescriptive method meant for homeowners who wished to improve their properties. Since the program was voluntary, Russell suggested a "different set of issues and incentives must be explored." These included: "Encouraging insurance companies to offer reduced rates for earthquake insurance..." Most of us know that the Insurance companies backed out of California earthquake coverage and most of us are now covered by a State run program. He also stated "Encourage residential mortgage lenders to require, in conjunction with existing state disclosure law (AB200), an evaluation of structural weaknesses and required retrofitting to a specific standard at the time of sale or refinancing." The last suggestion was to "Encourage both state and federal income tax deductions or credits for owner occupied properties and accelerated tax depreciation of retrofit costs for non-owner occupied properties...". Rather than continue, I suggest those of you interested in reviewing the seminar notes contact SEAOSC at their email address seaosc(--nospam--at)aol.com. As of this time, the most productive retrofit program has, as John suggested in his post, originated with insurance carriers who refused to provide Earthquake coverage until a positive evaluation was reported by a qualified engineer or architect. The majority of Insurance carriers have stropped offering earthquake coverage as of about a year or two ago (if you know of any offering new policies, please let me know). The private coverage has been replaced by a State run policy (similar to the one which failed in the very early 90's). It is my understanding that the current plan is a much more stable program. However, I do not know if they have followed the more stringent requirements of the private carriers. Also, as of this time, I know of no program (and maybe Fred Turner can shed some light on this) that offers any incentive for voluntary compliance such as a reduction of deductibles. One suggestion for the reduction in earthquake coverage that Fred Turner pointed out in his response to john Nichols earlier today might be that retrofit homes do perform better. The cost of potential damage in large metropolitan areas where the value of homes has peaked is expected to be less than the deductible from a moderate earthquake. This has caused many homeowners to reevaluate their coverage based upon expected loss compared to deductibles. In my area, the cost of land is so low even with the 10% deductible, it is worth carrying coverage on the low, and middle income homes. The average low income and lower middle income home in the Coachella Valley is under $100,000.00 - most loser to $80,000.00. since the majority of the cost of real-estate is in the structure rather than the land cost, it is more cost effective to insure these homes. We still have much work to do on making the public aware who is qualified to evaluate performance. I believe that the most homebuyers believe that this is covered in their mandatory home inspection services. It is not. Finally in a recent letter I received from Jay Crandell for the National Association of Home Builders, he suggested that I consider the following ways to help: "Dennis: If you would send me your complete address, I can add you to our research coordination group. As a research coordination group (RCG) member you will receive an annual program update including the research agenda, research summaries, etc. You will also be expected to constructively criticize the research plan/agenda using a one-page fax-back survey form. The next mailing should go out within a couple of months. Your other avenue is to become an associate member of the local homebuilder association affiliate with NAHB. This will link you in to NAHB's national meeting schedule and you could actively participate in meetings of the Housing Affordability Through Design Efficiency Program (as a non-voting member). However, your greatest contributions would be in your constructive input to the research agenda as an RCG member. There are about 90 RCG individuals, coast-to-coast in all walks -- public sector, private, engineers, architects, academicians, builders, etc. We are also in the process of starting a new organization to better link engineers, architects, and builders in a more productive exchange of needs and services. If you would like, I can include you on this mail list when it is Kicked-off. Jay" I would assume that this offer is open to any interested engineers. Those of you who are interested might contact Jay Crandell at jcrandell(--nospam--at)nahbrc.org. You might also seek out the following publications recommended by John Rose which I believe are being used as a beginning by NAHB: "For those who want to obtain Wood Frame Construction Manual (WFCM) for residential construction, contact: American Forest & Paper Assn./American Wood Council (AF&PA/AWC) 1111 19th St. (Suite 800) Washington, DC 20036 Tel. 202-463-2700 or FAX 202-463-2791 e-mail: awcinfo(--nospam--at)afandpa.ccmail.compuserve.com or Internet web site: http//www.awc.org John Rose/APA, Tacoma, WA" And, with this said, I will leave those of you followers of Fred Turner to the "better listserve where all the really serious discussions amongst SE's are taking place.":>) Dennis Wish PE -----Original Message----- From: John Nichols [mailto:cejn(--nospam--at)engmail.newcastle.edu.au] Sent: Thursday, May 28, 1998 5:07 PM To: seaoc(--nospam--at)seaoc.org Subject: RE: I Agree with Fred ! >> >Square foot for square foot, by far the more difficult to review. Load >path? Huh? A 10,000 s.f. house will normally take 10 times as long to >review as a 10,000 office/retail/educational structure. > >Of course in these parts, there isn't much money to be made in SFR's for >engineers. Conventional framing is used for the most part and an engineer >just comes in to analyse the odd beams, girders and columns. > >Ted Partrick, PE >Plan Review, Greensboro, NC > My point when I started the Tangshen thread is that it is the NC's that need that level of detail. When your buildings are tested it will be in one big blast not a series like Ca where there are enough small quakes (and they are small quakes relatively speaking with rapid east west attentuation.) to weed out the real lemons. It is not the building one is interested in it is purely to save lives. Unless the building details in the east and mid west have improved since I lived in Mo I would suggest that the cliche applicable is walking time bomb. The LAMB project of Abrams would suggest that the Feds may just be aware of this problem. The Rutherford and Chekene report on Memphis should be required reading for all structural engineers. I might say brilliant, but whomever wrote the report had a more than reasonable idea of what they were doing. Maybe some one from that firm follows the list. That is the other problem with hind sight its 20 : 20 Any way I have really enjoyed this debate. john nichols
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- RE: I Agree with Fred !
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