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Survey on the Benefits of EQ Mitigation

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This is a follow-up email to the one I posted in early March in regard 
to the mailing I sent out on the Benefits of EQ Mitigation to members of 
SEAOC.  They were due on April 15th (Tax Day!), and I did not get a great 
response rate.

So, I'm sending along my survey via this listserve, in hopes of receiving 
some more responses.  Before reading further, though, let me clarify a 
few things (from comments I've received on completed surveys).

First, I realize that the use of "expert opinion" to estimate damage to
structures from earthquakes is a controversial subject; I know engineers
strive to be as precise as possible (I'm one of them).  But, I would like
your opinion anyway - based on the limited information I give you. 
Additionally, the use of MMI was to be consistent with the ATC-13
guidelines only.  I'm not necessarily in favor of this scale.  Finally,
the separation of the two mitigation techniques is done to try to estimate
their effects separately (obviously), as well as together.  I admit that
some may disagree with this questionnaire approach. 

I'd like to thank those who've filled out the survey thus far, and thank 
others - in advance - for taking the time to fill it out.  Feel free to 
forward this survey along to anyone who has the experience to complete it.

Thanks!

Patricia
--
Patricia Grossi
Dept. of Systems Engineering
University of Pennsylvania
220 S. 33rd Street / 293 Towne Building
Philadelphia, PA 19104-6315 
pgrossi(--nospam--at)seas.upenn.edu
_______________________________________________________________________


To:		Earthquake Engineering Professionals

From:		Patricia Grossi
		Dr. Howard Kunreuther

Re: 		Survey on the Benefits of Earthquake Mitigation Measures for
		Residential Structures

Date:		March 6, 1998


Currently, faculty and students at the Wharton School of the University of
Pennsylvania are performing a research program entitled Managing
Catastrophic Risks.  The objectives of this research include determining
ways in which the public and private sectors can manage catastrophic
risks from natural hazards.  In the first part of our study, we are
studying the impact of alternative mitigation strategies on reducing
losses from future natural disasters. 

Our group is working closely with both the public sector, including
representatives of the Institute for Building and Home Safety (IBHS) and
the Federal Emergency Management Agency (FEMA), and three private industry
firms: Applied Insurance Research, EQEC AT, and Risk Management Solutions,
Inc.  Specifically, we are looking at the cities of Oakland and Long
Beach, California for earthquake hazard and Miami, Florida for hurricane
hazard. 

As you know, there is considerable room for judgment concerning damage to
structures during a significant earthquake event.  Due to lack of
post-earthquake damage data, expert opinion has been used to understand
this phenomenon.  The enclosed survey is in tended for earthquake
engineering professionals, and we hope to obtain some expert opinion on
the expected benefits of certain earthquake mitigation techniques for
pre-1940 wood frame housing. 

Wharton will only use the information you provide for research purposes. 
We will keep track of responses only in case a re-mailing is necessary to
obtain statistically significant results.  All responses will be
confidential and anonymous.  Furthermore, if you wish, we will share the
results of our study with you.  Just fill in your contact information at
the end of the survey. 

Enclosed please find your survey.  We would appreciate it if you took the
time to fill out this questionnaire (which should only take fifteen
minutes) and return it in the enclosed prepaid envelope by April 15, 1998. 

If you have any questions, please feel free to contact me by phone
(215-898-0026) or by email (pgrossi(--nospam--at)seas.upenn.edu). 


Thank you.




Enclosure  
________________________________________________________________________

Evaluating the Benefits of Earthquake Mitigation Measures for Residential
Structures

Your age: <25 yrs. 25-35 yrs. 35-45 yrs. 45-55 yrs. 55-65 yrs. >65 yrs. 

Yrs in practice: <5 yrs. 5-10 yrs. 10-15 yrs. 15-20 yrs. 20-25 yrs. >25 yrs. 

Your employer:	______	Structural Engineering Consulting or Design Firm
		______	Government (City, State, Federal) 
		______	University 
		______	Self-employed
		______	Other	___________________________________________

Please rate your experience with post-earthquake investigation of
residential wood frame construction:
	No Experience		 				Extensive
	at all	 						Experience
	0     1	     2     3	4     5     6     7     8     9     10 

In considering how to mitigate a structure to reduce the damage incurred
during an earthquake, there is a need to relate the cost of the mitigation
technique to its expected benefits.  According to the ATC-13 guidelines,
the mean damage factors (MDF or ex pected ratio of dollar loss to
replacement value) caused by ground shaking for a residential wood frame
building of standard construction for a given Modified Mercalli Intensity
are given below.  (For example, a MDF of 25 is defined as an expected
dollar loss of $32,500 for a structure that is worth $130,000.) Consider a
2,200 square-foot wood frame residential building in the city of Oakland,
CA.  It is a pre-1940 two-story structure with a market value of $130,000. 
It has 24" unbraced cripple walls an d it is inadequately bolted to its
foundation.  Do you agree with the values given in the ATC-13 guidelines? 
If not, please indicate your estimate for the mean damage factors for
ground shaking only (i.e. no collateral hazards such as ground failure,
fault rupture, inundation, or fire following). How do you feel about this
estimate? 

	MDF			Not Confident			Very
MMI	ATC-13	YOUR ESTIMATE	at all				Confident
VI	0.8	__________	0   1	2   3	4   5	6   7	8   9	10
VII	1.5	__________	0   1	2   3	4   5	6   7	8   9	10
VIII	4.7	__________	0   1	2   3	4   5	6   7	8   9	10
IX	9.2	__________	0   1	2   3	4   5	6   7	8   9	10
X	19.8	__________	0   1	2   3	4   5	6   7	8   9	10
XI	24.4	__________	0   1	2   3	4   5	6   7	8   9	10
XII	37.3	__________	0   1	2   3	4   5	6   7	8   9	10

What do you believe are the determining factors in the evaluation of this
MDF? 
				Not Important			Very	 
 				at all				Important
Square footage of structure	0   1	2   3	4   5	6   7	8   9	10
Age of structure		0   1	2   3	4   5	6   7	8   9	10
Number of stories of structure	0   1	2   3	4   5	6   7	8   9	10
Value of structure		0   1	2   3	4   5	6   7	8   9	10
Height of cripple wall		0   1	2   3	4   5	6   7	8   9	10
Inadequate bolting to foundation0   1	2   3	4   5	6   7	8   9	10
Any other factors?  
________________________________0   1	2   3	4   5	6   7	8   9	10
________________________________0   1	2   3	4   5	6   7	8   9	10

Consider the same 2,200 square-foot pre-1940 two-story wood frame
residential building in the city of Oakland, CA, with a market value of
$130,000.  One way to reinforce the structure is to brace its cripple
wall.  Please estimate how much the mean damage factors (MDF) would be
reduced with this type of retrofit for an earthquake with the following
Modified Mercalli Intensities.  How do you feel about this estimate? 

	% REDUCTION IN MDF	Not Confident			Very
MMI	AFTER MITIGATION	at all				Confident
VI	__________		0   1	2   3	4   5	6   7	8   9	10
VII	__________		0   1	2   3	4   5	6   7	8   9	10
VIII	__________		0   1	2   3	4   5	6   7	8   9	10
IX	__________		0   1	2   3	4   5	6   7	8   9	10
X	__________		0   1	2   3	4   5	6   7	8   9	10
XI	__________		0   1	2   3	4   5	6   7	8   9	10
XII	__________		0   1	2   3	4   5	6   7	8   9	10


Consider the same 2,200 square-foot pre-1940 two-story wood frame
residential building in the city of Oakland, CA, with a market value of
$130,000.  Another way to reinforce it is to bolt the structure to its
foundation.  Please estimate how much the mean damage factors (MDF) would
be reduced with this type of retrofit for an earthquake with the following
Modified Mercalli Intensities.  How do you feel about this estimate? 

	% REDUCTION IN MDF	Not Confident			Very
MMI	AFTER MITIGATION	at all				Confident
VI	__________		0   1	2   3	4   5	6   7	8   9	10
VII	__________		0   1	2   3	4   5	6   7	8   9	10
VIII	__________		0   1	2   3	4   5	6   7	8   9	10
IX	__________		0   1	2   3	4   5	6   7	8   9	10
X	__________		0   1	2   3	4   5	6   7	8   9	10
XI	__________		0   1	2   3	4   5	6   7	8   9	10
XII	__________		0   1	2   3	4   5	6   7	8   9	10


Now, consider a combination of these two mitigation techniques: bracing
the structure's cripple wall and bolting the structure to its foundation.
This is a "multi-level" approach to reduce the potential damage from an
earthquake.  Please estimate how much the mean damage factors (MDF) would
be reduced with this type of retrofit for an earthquake with the following
Modified Mercalli Intensities.  How do you feel about this estimate? 

	% REDUCTION IN MDF	Not Confident			Very
MMI	AFTER MITIGATION	at all				Confident
VI	__________		0   1	2   3	4   5	6   7	8   9	10
VII	__________		0   1	2   3	4   5	6   7	8   9	10
VIII	__________		0   1	2   3	4   5	6   7	8   9	10
IX	__________		0   1	2   3	4   5	6   7	8   9	10
X	__________		0   1	2   3	4   5	6   7	8   9	10
XI	__________		0   1	2   3	4   5	6   7	8   9	10
XII	__________		0   1	2   3	4   5	6   7	8   9	10


Finally, consider the TOTAL number of residential wood frame buildings in
the city of Oakland, CA, which is approximately 90,000 (including both
pre-1940 and post-1940 structures).  Please estimate the number of these
structures that are damaged requiring more than $1,000 to fix for an
earthquake with the following Modified Mercalli Intensities.  How do you
feel about this estimate?
	 
	NUMBER OF STRUCTURES	Not Confident			Very
MMI	DAMAGED (OUT OF 90,000)	at all				Confident
VI	__________		0   1	2   3	4   5	6   7	8   9	10
VII	__________		0   1	2   3	4   5	6   7	8   9	10
VIII	__________		0   1	2   3	4   5	6   7	8   9	10
IX	__________		0   1	2   3	4   5	6   7	8   9	10
X	__________		0   1	2   3	4   5	6   7 	8   9	10
XI	__________		0   1	2   3	4   5	6   7	8   9	10
XII	__________		0   1	2   3	4   5	6   7	8   9	10

COMMENTS:
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________


Thank you!  Please return this questionnaire in the enclosed prepaid
envelope by April 15, 1998. 

OPTIONAL:	

	Name:		_______________________________________________
	Address:	_______________________________________________
			_______________________________________________
			_______________________________________________
	Phone Number:	_______________________________________________
	Fax Number:	_______________________________________________
	Email Address:	_______________________________________________


The Modified Mercalli scale ranges from VI to XII (from Earthquakes,
Volcanoes, and Tsunamis: An Anatomy of Hazards by Karl V. Steinbrugge): 

VI 	Felt by all; many frightened and run outdoors.  Some heavy furniture
	moved; a few instances of fallen plaster or damaged chimneys.  Damage
	slight.  
VII 	Everybody runs outdoors.  Damage negligible in buildings of
	good design and construction' slight to moderate in well-built ordinary
	structures; considerable in poorly built or badly designed structures;
	some chimneys broken.  Noticed by persons driving motor cars. 
VIII 	Damage slight in specially designed structures; considerable in ordinary
	substantial buildings with partial collapse; great in poorly built
	structures.  Panel walls thrown out of frame structures. Fall of
	chimney, factory stacks, columns, monuments, and walls.  Heavy
	furniture overturned.  Sand and mud ejected in small amounts. 
	Changes in well water.  Disturbs persons driving motor cars.  
IX	Damage considerable in specially designed structures; well-designed 
	frame structures thrown out of plumb; damage great in substantial 
	buildings, with partial collapse.  Buildings shifted off foundations. 
	Ground cracked conspicuously.  Underground pipes broken. 
X 	Some well-built wood structures destroyed; most masonry and frame 
	structures destroyed with foundations; ground badly cracked.  Rails 
	bent. Landslides considerable from river banks and steep slopes. 
	Shifted sand and mud. Water splashed (slopped) over banks. 
XI 	Few, if any, (masonry) structures remain standing.  Bridges 
	destroyed. Broad fissures in ground. Underground pipe lines completely 
	out of service. Earth slumps and land slips in soft ground.  Rails bent 
	greatly. 
XII 	Damage total.  Waves seen on ground surfaces.  Lines of sight and 
	level are distorted.  Objects thrown upward into the air.