[CEUS-earthquake-hazards] The balance
Arthur D Frankel
afrankel at usgs.gov
Fri Jan 11 23:11:09 GMT 2008
Joe,
Here are the details of the calculations for a deep, stiff-soil site
(assume NEHRP site class D or S2 soil) in downtown Memphis at 35.15
degrees N, 90.05 degrees W:
1) For new Memphis code: Here I am using the procedure described in the
Amendment to Section 1615.1 in the Joint Building Code of Memphis and
Shelby County, effective Jan. 1, 2006.
Start with the 1996 hazard map value for 1.0 sec spectral acceleration
(S.A.) with 10% probability of exceedance in 50 years= 0.067g (BC,
firm-rock site condition). I am using 1.0 sec S.A., since the nominal
natural period of a typical 10 story building is about 1.0 sec.
Multiply by NEHRP site amplification factor of 2.4 for a D site (with an
input firm-rock, 1.0 sec S.A. value of 0.067g; table 1615.1.2 in 2000 IBC)
, you get 0.16g
2) For SBC (previous code used in Memphis), the rock-site value for 1.0
sec S.A. is 0.24g, based on the seismic zone map in SBC (Figure 1607.1.5A
in SBC 1999) and formula 1607.4.1.1 in SBC 1999.
For an S2 site class, you multiply by 1.2 (table 1607.3.1) to get 0.29g
So, according to these calculations for this site, the new code for
Memphis requires 0.16g spectral acceleration at 1.0 sec, whereas SBC as
used in Memphis until 2006 requires 0.29g.
Here I have not included the R (response modification) factors for
particular building types that are used to reduce the force levels in both
the SBC and the new Memphis code (which uses the R factors in the IBC).
These R factors are very similar between Table 1607.3.3 in the SBC and
Table 1617.6 in the IBC for most building types. Thus, these factors
will not affect the comparison for most building types.
I have had a structural engineer check my results and he concurred with
them.
Let me know if you disagree with these calculations.
-Art
Art Frankel
U.S. Geological Survey
MS 966, Box 25046
DFC
Denver, CO 80225
phone: 303-273-8556
fax: 303-273-8600
email: afrankel at usgs.gov
"Joe Tomasello" <JT at ReavesFirm.com>
01/11/2008 12:58 PM
To
"'Arthur D Frankel'" <afrankel at usgs.gov>
cc
<ceus-earthquake-hazards at geohazards.cr.usgs.gov>, "'Seth Stein'"
<seth at earth.northwestern.edu>
Subject
RE: [CEUS-earthquake-hazards] The balance
To all:
In response to Arts comments:
Local policy makers in Memphis were fully aware of both sides of the
argument.
We?ve reviewed a 10 story eccentrically braced system centered in Shelby
County and we came to different conclusions, base shear with 99SBC was
less than 03IBC amended with 10%PE (applied force was greater in 99 SBC
compared to 03 IBC). Can you share your calculations with us?
In my opinion, the code amendments adopted by local policy makers
efficiently address Memphian?s seismic safety concerns.
Joseph Tomasello, PE
5880 Ridge Bend Rd.
Memphis, TN 38120
From: Arthur D Frankel [mailto:afrankel at usgs.gov]
Sent: Thursday, January 10, 2008 5:53 PM
To: Joe Tomasello
Cc: ceus-earthquake-hazards at geohazards.cr.usgs.gov;
ceus-earthquake-hazards-bounces at geohazards.cr.usgs.gov; 'Seth Stein'
Subject: Re: [CEUS-earthquake-hazards] The balance
Joe,
Due to your efforts with Seth Stein, the building code in Memphis now
allows for non-essential 10-story buildings to be built to a force level
45% lower than that stipulated in the Standard Building Code that was used
in Memphis up through 2005. This newly allowed design level is
substantially lower than the median ground motions expected for a repeat
of the 1811-12 earthquakes and lower than the intensities reported in
Memphis for the 1843 Marked Tree, Arkansas earthquake (magnitude 6).
So you succeeded in lowering seismic building codes in Memphis. Perhaps
you would like to make this fact clear to the people living in Memphis and
see what their views on this are.
-Art
Art Frankel
U.S. Geological Survey
MS 966, Box 25046
DFC
Denver, CO 80225
phone: 303-273-8556
fax: 303-273-8600
email: afrankel at usgs.gov
"Joe Tomasello" <JT at ReavesFirm.com>
Sent by: ceus-earthquake-hazards-bounces at geohazards.cr.usgs.gov
01/09/2008 12:51 PM
To
<ceus-earthquake-hazards at geohazards.cr.usgs.gov>
cc
'Seth Stein' <seth at earth.northwestern.edu>
Subject
[CEUS-earthquake-hazards] The balance
Buddy:
I?d like to offer the following for your e-mail discussion group:
Natural disasters such as earthquakes create complex situations for policy
makers. The difficulty lies in the balance between the costs of mitigation
and the actual risk. Failing this, policy makers could find themselves
dealing with unintended consequences such as those experienced by the
hospital industry in California. If it?s worth the expense in any one
region it would be California; but looking at the hospital industry in
California we don?t see it.
Earthquake risks in California are, to some degree, statistically
predictable; being a near certainty that a moderate to strong earthquake
will occur somewhere on the west coast during a single generation of the
built environment. California attempted to balance public safety with
mandated seismic mitigation in a knee jerk reaction to the 1994 Northridge
earthquake California?s Legislature passed Senate Bill 1953 (SB 1953). The
bill was an unfunded mandate to retrofit, rebuild, or close; a free lunch
for California taxpayer. However, over the past decade the consequences of
the mandate caused a once sound hospital system transform into one of the
nation?s foremost financial basket cases.
As in California, policy makers in the New Madrid Seismic Zone are led to
believe that earthquake mitigation costs are small, having little effect
on the built environment. California?s mitigation program entails
retrofitting all acute care hospitals or re-building nearly 70 million
square feet. The pace of construction is limited to approximately 1.5
million to 2 million square feet per year due in large part to the ability
of regulatory agencies to keep up. Furthermore it takes upward of 10 years
to design and build a new hospital. ?The lengthy process for review and
approval of hospital construction and retrofitting projects is far too
long. Economic growth is being thwarted; jobs are being lost; and patient
safety is being compromised.?[i] The result is that it will take nearly
30 years to complete all the construction required by SB 1953. [ii] The
extended deadline is 2013.
The size and scope of most of these projects are very large and expensive.
Compliance could cost California hospitals as much as $110 billion
dollars. The original estimate assumed that the number of patients and
the number of beds would generally remain the same. However, modern
design standards are most effective with facilities 35% to 60% larger[iii]
. Thus, the scope of each construction project will increase as will the
overall cost; perhaps as much as 20%. [iv] In California construction
costs are rising at an annual rate of more than 14 percent above the
Consumer Price Index resulting in construction costs more than 40 percent
higher for comparable facilities in other states.[v] In my view this
increase is likely to continue do to regulatory oversight, the limited
number of qualified contractors, as well as the annual inflation of
material costs. In California, a fully furnished and equipped acute care
facility (labor and materials) costs $1,000 per square foot. Since the SB
1953 mandates affect for-profit, non-profit and publicly owned
organizations most all projects will be financed. Depending on the terms
of the loan the cost in current dollars for an acute care facility the
square foot cost can exceed $2,800; comparatively normal office
construction in Tennessee is roughly a third the cost per square foot.
Looking at FEMA?s annualized earthquake losses[vi] we find the
relationship of Cost vs. Benefit even more lopsided. FEMA reports that
California will experience a loss of approximately $3,167.5/$Million of
infrastructure each year as a result of earthquakes. Looking at the same
50 year period, California can expect to lose approximately 15.8% of the
present value of hospitals. Thus, California?s acute care infrastructure,
worth approximately $48 Billion [my estimate - C. Duane Dauner, President
and Chief Executive Officer, California Healthcare Association, Statement
?Heath Care Scene in California,? May 10, 2001, suggested 24 Billion.],
should expect a loss of approximately $7.6 Billion due to earthquake. We
find that California is spending $110 Billion to offset a loss of $7.6
Billion; a cost benefit relationship greater than 14. Over the past 10
years, we?ve asked FEMA for a Cost vs. Benefit analysis for the New Madrid
Seismic Zone. So far we haven?t seen anything that would come close to
suggesting that the public would benefit spending limited resources.
There are a more subtle negative consequences resulting from forcing acute
care facilities to close because they don?t meet mandated requirements.
California is experiencing a critical closure of hospitals with the
closure of over 50 hospitals in the 10 year period between 1995 and 2005.
More than 3,000 acute care beds have been removed from service between
2001 and 2005. In the five year period prior (1995 to 1999) 23 hospitals
closed. Unfunded mandated seismic requirements are creating a stampede for
funding, usually in the form of bonds. The median credit ratio of
California hospitals had nosed dived to the junk-bond status. The money
needed to retro fit California hospitals is drying up. [vii] ?Nobody can
bear the burden [of SB 1953 unfunded mandate]?[viii] Here in the New
Madrid Seismic Zone we?re told that the cost is minimal.
?Seismic upgrades are important. But mandating them during the worst
economic time in the history of California hospitals is like ordering a
homeowner to fix a dilapidated porch on a house that's on fire. Right
idea. Wrong time.?[ix] How many doctors and nurses could have been hired
in lieu of spending the money on hospital infrastructure? Just how many
lives will be saved? How many lives will be lost because of the loss of
acute care facilities? Who pays, the bottomless pocket of the taxpayer?
Each of the 35 million people in California will need to pay $3,143 (per
capita state and local taxes were roughly $1,600 in 1996). Are the people
of California going to be willing to forfeit three times their current tax
burden?
If the benefits (reduction of earthquake related economic loss or lives
lost) don?t outweigh the costs in California, how can they be justified in
the New Madrid Seismic Zone?
Joseph Tomasello, PE
5880 Ridge Bend Rd.
Memphis, TN 38120
Phone:
(901) 761-2016 office
(901) 821-4968 direct
(901) 412-8217 mobile
[i] California Heathcare Association Statement on the Hospital
Construction Plan Review and Area Compliance Process before the California
Performance Review Commission, U.C. Riverside, August 13, 2004.
[ii] Ibid., 4
[iii] Ibid., 41
[iv] Ibid., 8
[v] Ibid., 30
[vi] FEMA 366 Hazus 99 Estimated Annualized Earthquake Losses for the
United States, February 2001, 16
[vii] California HealthCare Foundation, The Financial Health of California
Hospitals, June 2007, 2-13
[viii] Ibid., (interviews with key unnamed health care leaders), B-6
[ix] The Press Democrat, Another hospital falls, what killed Sutter
Medical Center ? and what will it mean to families like mine, January 14,
2007_______________________________________________
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