Ups
Engineering Field Notes
Administrative Distribution
Professional
Development
Ser-vice-U.S.
is
an
administrative document
publication
for the guidance
of employees of the
This
Management
Data
Retrieval
was
that
developed
Forest
and its
Department of Agriculture its contractors
Federal and State Government Agencies.
The text
cooperating
in
the personal opinions
the publication represents
of
the
authors.
This
information has not been approved for
respective
recom-mended
instruc-tions
and must not be construed
to the public
distribution
as
approved policy procedures or mandatory
except
by Forest Service Manual references.
or
in-formation
con-venience
The
no
Forest Service-U.S.
names and
by other than
of the
any product
or
Agriculture
own employees. The
use
is
to the
exclusion
of
others
suitable.
This
information
unlimited rights
by private
Please
any comments
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Carroll
M.J. Baggett
P.O. Box
Telephone
that
may
be
the sole property of the Government with
the usage thereof and cannot be copyrighted
or
recommendations
FOREST SERVICE-USDA
D.J.
trade
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Engineering
of
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assumes
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by the United States Government of
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or
its
of
or application of this
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Department
for the interpretation
responsibility
Office
Editor
Editorial
2417-Washington
Assistant
D.C.
20013
Area Code 703-235-8198
about
this
Letter
United
States
From the Chief
Forest
Department of
WO
Service
Agriculture
Reply
to.
Subject
To.
Dale
1320
Technology
Regional
Transfer--Engineering
Foresters
Station
Field
Directors
j
ýH1
2
IBC
Notes
and Area
Director
One of the best tools we have for fostering
transfer
technology
and improving our effectiveness
as resource
is open
managers
communication
with our co-workers.
A good way to achieve
this open
communication
is by using some of the excellent
print media that
within the Forest Service.
are available
One example of effective
use of the print medium is Engineering
Field Notes EFN.
Engineering Field Notes has been helping
and Engineering Technicians
share their professional
Engineers
Service-wide
since 1969 it has given colleagues--who
experiences
have never met--the
to learn from one another
and has
opportunity
ideas and experiences
the
stock
of engineering-related
enlarged
Service-wide.
I
has saved
am certain that the Forest Service
substantial
time and money over the years through
the efforts of
those who have authored
and read EFN articles.
units to continue
to read and feed EFN.
urge all Forest Service
In these belt-tightening
times it is important that we share as
much of our professional
skills experiences and ideas as possible.
Engineering Field Notes has proven to be a good way to do that.
I
R.
MAX PETERSON
CHIEF
UýiS
OrA
ERRATA
Engineering Field Notes would like to give belated
credit to Geophysical Survey Systems Inc. for
furnishing all of the illustrations used in Ground
Penetrating Radar
A Review
for Resource
Managers
Author. Jerry D. Greer Nationwide Forestry
Applications Program Engineering Field Notes Volume
18 September-October 1986.
The credit line was inadvertently
article was published.
omitted
when
the
--Editor
Some Thoughts on
Professionalism
Ted Zeally
Preconstruction
Chief Transportation
Office
Engineering
Washington
CONCEPTS of
PROFESSIONALISM
Engineer
con-cern.
technician--are
For-ests.
As
I
I
associates around the Forest Service
times a feeling of discomfort and
visit with
sense
at
All of
us--foresters engineers
biologists
and many others both professional and
working at a time when we cannot do all that we
National
think should be done to manage
Limitations of personnel and budget preclude
our doing what we perceive to be a professional
With the call for reduced
standards some may
job.
do
not
want a
leaders
feel
that
our
even
our
profes-sional
con-cepts
product.
recently read an article by Samuel P. Huntington
Harvard
a
professor that may help us put our
and
of professionalism in proper perspective
heads
little
hold
our
a
Huntington
higher.
help us
defined professionalism within the bounds of three
expertise responsibility and
concepts
I
corporate-ness.
special-ized
The
Expertise
human
Responsibility
field
of
endeavor.
The
is a practicing
expert
professional
in a social context
and
working
performing a
service
that is essential to the functioning
of
Corporateness
is an expert with
professional
skill
in a significant
and
knowledge
society.
The
members of a profession share a sense of
of themselves
as a
organic unity and consciousness
from
This
collective
sense
has
laymen.
group apart
and training
its origins in the lengthy discipline
the common
competence
necessary for professional
bond of work and the sharing of a unique social
responsibility.
WITHIN
the
SERVICE
FOREST
As you consider your job within the Forest Service
are you not better qualified to perform your job
Whatever
than someone outside our organization
a
1
may be that person is part of
professional organization having a corporate body
of very specialized knowledge
and
skill.
And I hope
we all share the belief that managing
National
Forests for ourselves and
most importantly for
more than 200 million clients
is a significant
human endeavor.
persons specific
job
g
a
our
We may not now be able or required to apply all the
skill and knowledge
that we have developed
over the
The
doctor
that
years.
you visit when you have a
cold may have the skill and knowledge
to remove your
appendix is that doctor less a professional for
giving you only the treatment you need to cure your
cold
Certainly you justifiably could accuse that
doctor of unprofessional
conduct
were he or she to
when
it
Our
remove your appendix
was unnecessary.
inside
and
outside
the
Forest
clients
Service
level
now are only asking us to use an appropriate
of our professional
skill and knowledge
as we do our
Forests.
We are no
part in managing the National
less professional
now than when we were called upon
to exercise different aspects
of our professionalism.
to
Certainly all of us are performing a service
Service
to
is
a
society.
society
key aspect of
When
a
doctor
ceases
to serve
professionalism.
in
that
doctor
is no
society
an acceptable
manner
to
of
authorized
longer
regardless
prior
practice
skill or knowledge.
Our National
Forests are an
important asset and heritage to manage and protect
for citizens.
Many of us are called upon to serve
in difficult
and even
areas and under uncomfortable
conditions.
We
are
motivated
by values
dangerous
and ethics somewhat peculiar to our professional
organization.
And do not we all belong to that corporate body
called the Forest Service
Forest Service employees
fit
the
last
of
certainly
Huntingtons criteria
would classify us as a
corporateness.
Huntington
bureaucratic profession one that renders
We do not
service
to society as a whole.
serve society fully by practicing
our individual
We provide the greatest
professions
independently.
service to society as we act corporately and
col-lective
col-lectively.
our-ATTITUDES
OU R OWN
comes down to our own attitudes about
and the jobs we have.
If we recognize
and
expertise responsibility
corporateness
It
all
selves
2
our
we
can
profes-sional
the
see that we continue
to provide
service that has so long been the hallmark of
the Forest Service.
If we approach
our tasks
then we shall remain in spite of the
task we may be called upon to do today
particular
readily
profes-sionally
professional.
3
RTIP Update
Ted Zeally
Chief Transportation
Preconstruction
Office Engineering
Washington
RTIP 5 CLEARING
GRUBBING
Issue
method
Engineer
is selecting the
lowest cost slash disposal
consistent with management
needs and Issue 2
is selecting minimum clearing
limits consistent with
needs.
management
1
Action Items 5-1-1 5-1-3 and 5-2-1
5-2-3 dealt
with selecting the lowest cost slash disposal options
and
clearing limits consistent with management
needs.
In April 1986 the Washington
Office sent a 7700
letter to Regions
outlining systematic methods to
make such selections.
Art Marty and Jack Weissling
subsequently
published articles covering these
in
topics
Engineering Field Notes.
empha-sized
The
Roads Productivity
Team also
Improvement
these issues in their report to the Chief in
October 1986.
The final PIT Report should be sent
to the field early in 1987.
Action
Items 5-1-2 and 5-2-2 required the revision
Standards
FSH 7109.52 to
Activity Evaluation
include evaluation
criteria covering the systematic
selection of low-cost slash disposal options and
A proposal was developed
clearing limit widths.
and
submitted to the Regions
for comment in May
1986.
Based on field input the final draft
was changed to include the systematic
of all road design standards in the
activity
evaluation
standards for Preconstruction.
The
amendment
to FSH 7109.52 was signed by NFS in
November
1986.
of
revi-sion
selec-tion
4
Buffalo Pass Turnkey
Jerry Lancaster
Contract Officers
Representative
Steamboat
Zone
Forest
Routt National
INTRODUCTION
Wayne Hamilton
Zone Engineer
Steamboat
Zone
Routt National
Forest
Engineering Zone of
February 1985 the Steamboat
Forest was given the opportunity
the Routt National
to prepare and administer what we think is the first
Turnkey road construction project in the Forest
Service.
In
con-structed
Turnkey
is one that is designed
project
The
and inspected by the contractor.
contractor completes. each phase of the project and
submits the work for approval by the Forest
The contractor submits inspection reports and
test results to the Forest Service Engineer and the
Forest Service performs compliance
testing and
A
Ser-vice.
inspection
BACKGROUND
as
necessary.
The Buffalo Pass Road was chosen for this project
This road
because of its heavy recreation use.
provides access to several lakes and campgrounds
and it serves as a major access point to the Mount
Zirkel Wilderness
Area.
At its beginning at the
of
the
of
Steamboat
Colorado the road
edge
city
It was a
to several homes.
provides access
14
road with a surface width of approximately
and
the
road
had
severe
drainage
problems.
feet
All of the fine aggregate material had washed away
from the surface leaving
large rocks protruding
the
subgrade.
through
single-lane
REQUIREMENTS
Under the contract
the existing road was widened
to
a 26-foot-wide
subgrade plus necessary curve
widening and 8 inches of compacted gravel was
This project was one of the Routts most
applied.
difficult
road construction
jobs because of its use
Several thousand cubic
and nature of construction.
yards of rock required drilling and blasting see
Much of the drilling and blasting
figures 1 and 2.
had to be done adjacent to existing homes along the
5
c
Figure 1.--Typical
4
rock
section
during
early stages
of
construction.
I
Fr
Figure
2.--Typical
rock
6
section
during
final
shaping
of
subgrade.
roadway.
Existing driveways had to be maintained
lines had to be replaced and
power and telephone
traffic delays could not exceed 1 hour at a time.
BIDDING
PROCESS
Unlike other road construction
projects which have
The
several bid items this project had only one
of
and
Construction
Design Construction Staking
The Method of Measurement
was
3.0 miles of road.
Lump Sum.
The Engineers Estimate onthis job was $464000.
There were five bidders with bids ranging from
The job was awarded to
$420000 to $539000.
from Grand Junction Colorado
Richmond Construction
for $420000.
After five change orders the final
amount turned out to be $428113.
contract
DESIGN
The contractor was required to submit a resume for
The
the engineering firm he planned to use.
engineering firm had to have had a minimum of 5
years of. road design experience including at least
two design projects in mountainous terrain.
The
design criteria and warrants were specified in
the
and the
contract
design was submitted at various
When the design
stages for Forest Service approval.
done
in the field
a plans-in-hand
was
was complete
before approval.
This plans-in-hand
step is
because once the plans are completed and
approved all design changes will result in cost
It is also very important to include
adjustments.
the prime contractor not just the designer during
the
review process to make the prime contractor
aware of any changes in the design.
crit-ical
The engineering firm for this project asked for and
received our survey notes and visited the project
before bidding.
They plotted up a cross section
feet
in the common material and every
every 1000
500 feet in the rock.
They then offered preliminary
and
an engineering
quantities
quote for the design
construction
staking and construction
inspection to
the prospective
bidders provided that the bidder
would lock them in at their quote.
The successful
bidder was the only bidder to agree to this and
thus was the only bidder to have access to these
This information was the
preliminary quantities.
bid.
key to the successful
7
CONSTRUCTION
Construction
staking was accomplished
by the same
engineering firm after the approval of the design.
We recommend that the staking be done after the
preliminary approval but before the final approval
of the plans.
This step allows physical review of
the
stakes before acceptance
of the design.
QUALITY CONTROL
The
contract
required quality control by the
This involved
sampling and testing and road
A quality control plan was required
inspection.
that included authorities responsibilities and
and qualifications
of inspecting and
experience
The contractor had to submit the
testing personnel.
It was the
plan 5 days before beginning work.
contractors responsibility to maintain and keep
and tests
current all records of inspections
All documents were provided to the
performed.
for review.
Contracting Officers Representative
CONSTRUCTION
All work was performed
and 1986.
The job was
CONCLUSION
Turnkey concept is ideal from the standpoint
staffing for the valleys in workload and still
It
also is a
being able to cover the peaks.
reasonable
solution to an emergency job--one in
which the construction
must be completed in a short
The job can be offered as a
period of time.
Turnkey and thus eliminate 2 years of
time savings.
engineering time--a significant
A significant
cost savings was not apparent
on this
job however we believe that contractors will
submit lower bids on difficult projects if they can
tailor the design
to their available
equipment and
manpower.
STAKING
contrac-tor.
during the summers of 1985
on July 30 1986.
accepted
The
of
preconstruc-tion
For more information contact Jerry Lancaster
Wayne Hamilton at 8-303-879-1722.
8
or
Valle Vidal Global Positioning
GPS Demonstration Project
System
Dennis J. Mouland
Land Surveyor
Regional
Southwestern
Region
INTRODUCTION
In 1982 the Pennzoil
100000
Corporation donated
Forest in northern New
acres to the Carson National
Mexico.
Initial surveying and engineering work was
done to provide maps legal descriptions easements
It was discovered
that the
and road construction.
area was very poorly covered by the national
The adjoining Questa Ranger
reference system.
These factors
District also was poorly covered.
various
on the Valle
limited
operations
greatly
Vidal unit especially
in mapping and survey
geo-detic
opera-tions.
In fiscal year 1986 the Washington
Office provided
Land Line Location funds for Global Positioning
3
demonstration projects.
System
Region
obtained $25000 and decided to conduct
a geodetic
control densification
project in the area of the
Valle Vidal Unit.
The total project area included
1200 square miles. Within that area
approximately
five
stations were known
existing
triangulation
only
GPS
at
PROJECT
PREPARATION
the
time.
obstruc-tions
mountain-tops
Because of the limitations with the GPS receivers
from trees and other
regarding interference
the project
below 20 feet above the horizon
All stations were close to
site was a good choice.
or above the
tree line and were never near any
All stations would be set on
objects.
be required.
or ridges where no clearing would
man-made
The project site is in rugged mountainous country
with elevations ranging from 8000 feet to more than
The average
elevation for the new
13000 feet.
stations was 10500 feet.
All stations were
In May
1986 a crew went
only by helicopter.
in for 3 days and toured the entire project area to
select new station locations and verify existing
monumentation.
acces-sible
9
Actual monumentation of the new stations was delayed
until July when most snow cover was gone.
Stations
were set using precast concrete
monuments placed into
fresh cement in excavated
Three stations
holes.
fell on bedrock
and were marked by brass
conveniently
disks epoxied to the rock.
were written to acquire the actual
Specifications
GPS
services.
a
Although
price was a major factor
set of evaluation
criteria was established
to make
sure firms had appropriate
GPS
experience.
is a relatively new technology
and very few
engineering or surveying firms have ever tried it.
sur-veying
equip-ment
The
criteria
in
required the firm to have experience
in
GPS experience
geodetic computations equipment
that had been across the NGS test range
and
that could
be handled by two persons if walking
was required.
Seven firms submitted quotations
on
the project
and four were found to be technically
The highest scoring firm also submitted
acceptable.
the
lowest quotation.
There was very little dollar
difference among the acceptable
firms.
No
two firms proposed to use the same models of
The contractor was allowed to use any
equipment.
number of units and use any field operation desired
Geodetic Survey NGS
as long
as the National
were met.
The final product was to be
and
and
elevations on
state-plane coordinates
all of the new stations.
GPS 4th order accuracy was
The Forest Service would provide the
required.
helicopter.
stan-dards
geo-detic
struc-ture
The
successful
contractor was Sunrise International
who proposed to use the ISTAC 2002
codeless
receivers four units.
The payment
allowed for a mobilization-demobilization
fee
to be paid and
a per-point
price for ties to existing
stations and setting of new station positions.
Prices were as follows
of
Mesa
Arizona
Item
1
Mobilization/Demobilization
Item
2
Ties
Item
3
New
Project
to
Existing
Stations
Stations
Lump
sum
$4000
$4000
5
ea.
530
2650
18
ea.
530
9540
$16190
Total
10
TECHNOLOGY
TRANSFER
in the area
obtaining geodetic positions
Although
the main emphasis
was the purpose of the project
was on exposing the Land Surveyors of the Region to
GPS.
All land survey personnel with one exception
This included
from the Region were able to attend.
all surveyors and all technicians including
The Region tried to make this a
people.
major training and exposure opportunity for all.
The chief design engineer for Motorolas GPS
was invited to provide formal training on the
GPS
basics of GPS.
He also brought their 14-pound
which
used
to
several
other
land
was
receiver
try
of GPS technology.
surveying applications
non-permanent
divi-sion
A private
land
surveyor the Region 3 Director of
and the helicopter
Lands and Minerals
support
the
total number of participants
personnel brought
The training and then the
to 35.
real hands-on use
of two different models of GPS equipment proved to
transfer.
be a fantastic
example of technology
PUBLICITY
TOO
ACTUAL PROJECT
A television news crew from CBS in Albuquerque
spent
2
and we got some very good
days with the project
They did a special segment
publicity as a result.
entitled High Tech in the Heavens which aired a
The Albuquerque Journal is planning
few days later.
article
in
the
near future describing the project
an
and the technology.
after months of logistical preparations
the project was conducted
in September
1986.
The
of
because
a special helicopter
project
required use
of the high altitudes
and
the weights involved.
The
weather was a major factor
and
the first 3 days saw
constant changes in plans because of low clouds and
On the afternoon of the third day a sudden
rain.
snowstorm entered the area and two people were
stranded on top of a 12500-foot peak.
They had to
hike out before nightfall and a rescue party was
sent in to locate them and get them back to the
lodge.
Finally
Another problem that came up was the battery power
The cold seemed to affect the
on the ISTAC units.
batteries charging ability and the generator at
the base area may have contributed
to additional
Even with these
problems of voltage irregularities.
situations the project was successfully carried
out with only one of the new stations never being
That station was at 13000 feet and was
occupied.
never out of the clouds long enough to occupy and
make observations.
11
There was no phone service at the base area so all
data reduction
had to be done by the contractor
after returning home.
The Forest Service received
final data 3 weeks later which revealed that the
times
results far exceeded the plan.
Observation
55
90
a
from
minutes
to
minutes
and
ranged
produced
much higher quality of accuracy
in
the
first
mostly
and second order area.
Moving one of the satellites
did not bother the ISTAC
during the project
because it does not use the transmitted codes
for data reduction.
equip-ment
CONCLUSION
The
success both as a
project was a resounding
and
as
a
real-life geodetic
training opportunity
GPS
We
that
does
work in any kind
project.
proved
of weather
that the logistical problems can be
dealt with and the future of surveying will include
GPS as a major source of data.
The ISTAC equipment
the
weight was at times
performed well although
The battery problem caused some difficulty
awkward.
and could be prevented
in the future with more
and forethought.
plan-ning
on this project were about
the helicopter
time for
and
GPS--an
overall
reconnaissance
monumentation
More than half of the
cost of $2500 per point.
total cost was helicopter-related.
Total
expenditures
$45000 including
all
plan-ning
The
Region is grateful
We are convinced
a
big part in our
play
new and different
with GPS technology.
GPS.
12
for the opportunity to try
that this new technology
will
future. We are already
Forest Service applications
Engineering Systems Guidelines
Standards
Jerry D. Bowser
Office Staff Engineer
Washington
System Operations Analysis
Development
INTRODUCTION
During the period of May 6 through 8 1986 Regional
Engineering Systems representatives and Washington
Office Engineering Systems staff assembled
in
Arlington Virginia for an Engineering Systems
worked on some
National Workshop.
Participants
software development
and maintenance
guides that
should have national utility.
SOFTWARE
DEVELOPMENT
These guidelines should assist programmers and
new programs.
systems managers who are developing
whenever they seem
They should be followed
to the
type of program under consideration.
Direct benefits of the guidelines will be lower
costs more easily understood programs better
maintained programs and greater flexibility if
future enhancements
or changes
are needed.
GUIDELINES
appro-priate
1
Try to trap common errors and give the user
understandable
Avoid leading error
responses.
to
the
operating
trapping
system default
codes.
For example error 44A could be
replaced with
problem has occurred with the
of
space manager please refer to page
a
2
3
4
manual.
_
Use variable names that are as meaningful to
the user as possible without
being excessively
long for example use total instead of
tl.
menu structure for programs that will
primarily by inexperienced computer
Provide alternate methods for
users allowing them to bypass the more
time-consuming menu-driven sections.
Provide
be used
users.
experi-enced
Maintain a menu hierarchy to
order of any current process
next logical process.
13
reflect the logical
and possibly the
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
references
to the users manual at
times
within
the program to assist
opportune
those with additional questions.
Provide
Display date system name and revision number
on the main menu.
Label subsequent menus with
identification of their location within the
program.
Avoid using menus that contain more than
selection items they are less efficient
the end user.
eight
for
Provide meaningful prompts
levels within the program.
at
and
help
keys
all
Provide a mechanism that allows the end user to
make a file selection from a catalog rather
than requiring the user to type a file name.
func-tions
Standardize the programming of special
keys where possible for example on the
CEO template use Fll for cancel/exit
F8 for
delete character and so on.
Follow the concept
all levels.
of
modular
programming
at
Use
full-screen editing techniques
when data
and
when
are
a single
inputs
required
prompts
is
response
expected.
Use device drivers
data output.
to
facilitate
transportable
Use
code-generating
Use
system software as much as possible
PRESENT
on the Data General.
programs
where
appropriate.
example
remarks
Integrate descriptive
define process internally.
into
Include authors name and contact
within the code.
Write auto
within the
copy
and
auto
load
code.
Design all data structures to
with future expansions and/or
14
code
for
to
information
capabilities
be
help
compatible
enhancements.
SOFTWARE
MAINTENANCE
IMPLEMENTATION
STANDARDS
The Maintenance
and Confidence Level for all
be public information.
should
engineering programs
These descriptions are an indication of what the
user can expect when operating a certain piece of
The following
software.
are definitions
useful to
the level descriptions
understanding
1
2
Maintenance
Levels
Level
Documentation.
History
organized manner.
Clean
Code
Code.
that
structured modular.
file source code
is well
documented
Maintenance
Level 1.
Level 1 programs are fully
maintained.
An appointed
person takes care of the
and operation.
These programs
program maintenance
are fully documented
the code is
and a
users guide is available.
Whenever
the user
encounters
a problem
in the program
the user can
call the person in charge of maintenance
for the
This person
program to get the problem corrected.
will tell users what they are doing wrong how to
get around the problem or will fix the program to
correct the-problem.
In any case
the problem is
corrected withinl to 3 days from the time the users
clean
call.
An example of level 1 maintenance
is how
been maintained for the past years.
RDS
has
main-tained
Maintenance
Level 2.
Level 2 programs are
time permits.
An appointed
person
maintains the program this is often the person who
the program.
These programs may or may
developed
not be documented
and the
code is not likely to be
clean.
A users guide is available.
Users can
call the person in charge of maintenance
whenever
a problem.
This person may tell the
encountering
user what he or she is doing wrong or how to get
around the problem.
However if the problem
requires a program fix the maintenance
person will
only work on the program error as time permits.
as
An
would
example of level 2 maintenance
developed
by a Region
employee and then
for all Regions
by that employee.
be
a program
maintained
Maintenance
Level 3.
Level 3 programs are not
usually maintaine
However an appointed person
keeps the programs operational whenever hardware or
system software change.
These programs may or may
15
avail-able.
not
documented
and
the code is not likely to be
A users guide may or may not be
Users are expected to use the program as is.
In case of a problem users must try to figure a
solution out themselves from the users guide
if
one is available.
be
j
clean.
An
is a program
example of level 3 maintenance
picked up from another agency or a program developed
or Forest that the Region
or Forest does
by a Region
not have the time to maintain for everyone else.
main-tained
Maintenance
Level
Level
programs are not
to keep the
appointed
Should
hardware
program operational.
or system
software changes make these programs inoperable the
These programs
programs are likely to be abandoned.
may or may not be documented and the code is not
A users guide may or may not
likely to be clean.
be available.
Users are expected to use the
as is.
In case of a problem users must try
to figure out a solution on their own.
at
all.
4.
one
No
4
is
pro-grams
An
is a level 3
example of a level 4 maintenance
to keep the
program when the person appointed
program operational leaves and no one else can be
found to take over the program.
Levels
Confidence
the time.
Level 1.
These programs work
contain
few if any known
They
nearly all
problems.
Confidence
Level
2.
These programs work most of the
contain
a
number of known problems that
They
bypassed
by adjusting the way the program is
or by adjusting the data.
time.
can be
used
Confidence Level
users usually can
These problems work however
some problems.
expect to encounter
3.
Confidence
Level 4.
These programs have numerous
Users
should
be extra cautious
about
bout
problems.
using them and should question results they give.
g
Confidence
16
3
PAIRWISE A New Decisionmaking
Tool
Available to Forest Service Engineers
Robert J. Hrubes
Sciences Staff
Management
Pacific
Southwest
Forest
Range Experiment Station
PREFACE
office
described in a recent Washington
Making Sound Facility Development
Decisions EM-7310-2 and in a forthcoming PSW
Experiment Station publication.
PAIRWISE
is
publication
Office
PAIR WISE also was mentioned in the Washington
on facilities planning.
presentation
slide/tape
This presentation released September 1986
currently
Contact
is being routed to all units for viewing.
Facilities Engineer for details.
your Regional
fre-quently
and planning decisions
Engineering management
involve the analysis and selection of a
preferred alternative from among a set of several.
Alternatives
usually represent proposed courses of
action.
Prospective alternatives or courses of
and
their expected performance
action
are examined
compared to a set of goals or objectives relevant to
the particular problem being addressed.
Goals and
criteria.
objectives are represented by evaluation
The preferred alternative is the alternative judged
with respect
to present the best overall performance
to all criteria.
When
as is usually the
case a problem involves
several alternatives and evaluation
criteria the
task quickly becomes very complex and
decisionmaking
The number of comparative
burdensome.
judgments
rises exponentially
required by the decisionmaker
with the number of alternatives and evaluation
criteria.
Unfortunately.a common response of
for ad hoc
decisionmakers
is to opt
informal and
With such procedures
procedures.
noncomprehensive
the chance for making an inappropriate and poorly
documented decision
is significant.
17
PAIRWISE
was designed to improve the quality of
decisions
in multiple-alternative multiple-criteria
The method breaks down complex problems
problems.
into a structured and manageable
set of pairwise
comparisons.
Using proven and tested procedures
found in the operations
research literature on
takes the results of these
decisionmaking PAIRWISE
comparisons and produces an overall ranking of the
alternatives.
The decisionmakers judgmental path
and
to this final ranking
is highly traceable
not present in many other
documentable--qualities
methods.
avail-able
Of
equal
importance
to
Forest
Service
Engineers
The model is structured
PAIRWISEs ease of use.
an interactive
menu-driven
computer program
is
as
is
for use on the Data General.
Once PAIRWISE
installed at a local computer facility PAIRWISE
is
The user is prompted to
easily accessed and used.
provide the comparative
judgments necessary to arrive
at a final ranking.
The model can factor in the
judgments of one or more decisionmakers.
of PAIRWISE
also is straightforward
and
the program simply is imported to any
Forest Service Data General computer facility using
Procedures
commands.
for acquiring
simple
PAIRWISE
for your computer facility are listed below.
Installa-tion
uncom-plicated
IS
If
to
or
you have any comments or questions address them
Robert Hrubes at FTS-449-3306
or DG R.HRUBESS27A
to George Lippert
FTS 235-8020 or DG.
G.
LippertW01B.
INSTALLING
PAIRWISE
The PAIRWISE
via IS from
programs can be retrieved
the PSW computer installation.
We recommend
that
the programs be installed in either a staff or public
IS
class of potential users
drawer depending
on the
for the software.
Contact your IS information manager for your staff
and request that he or she create a drawer and folder
in ISs staff or public area with the following
designations
Drawer LIBRARY
Folder
This drawer
for maximum
7100PAIRWISE
and folder
size.
18
should
have
2000 blocks
1
2
3
4
MENU
From IS MAIN
NL.
press
select
From UTILITY FUNCTIONS
select
and FCCC Access and press NL.
In
the
table
Retrieval
1.
IS Retrieval
Utility information
information
enter the following
Location
of
For Host
Name
NL.
Select
file to
level
2.
be
Staff
Name
For Staff
NL.
press
NL.
For File
press
NL.
Location
Select
Name
Name
type
For Drawer
press NL.
For Folder Name
and press NL.
For File
press NL.
type
Name
and
and
press
press
to
PROGRAMS
and
PAIRWISE.DMP
put
the
appropriately
Name
Y
type PAIRWISE_EXPORT
type
in which
level
and press
type MaSS
For Drawer Name
and press NL.
For Folder
retrieved.
type S27A
NL.
b
6.
and
Access select
From Retrieval
and FCCC
retrieval and press NL.
a
5
Utilities
3.
file.
and press NL.
type LIBRARY
type
and
and
7100_PAIRWISE
type PAIRWISE.DMP
and
After the retrieval request has been completed
the drawer
return to IS MAIN MENU and access
and folder where PAIRWISE.DMP
was stored.
You need edit permission for the PAIRWISE
drawer to perform the remaining steps in this
set of instructions.
19
6
7
If
USING PAIRWISE
FIRST TIME
for
command
previous command was executed
PAIRWISE..DMP can be deleted. Enter
PAIRWISE.DMP
in the
IS command
line and
the
press NL.
Edit file PAIRWISE.CLI to include in the
SEA CLI command
the full pathname of the
directory where the PAIRWISE.PR
file resides
for example
the
IS
success-fully
DEL
8
inthe
Enter LOAD/V/R
PAIRWISE.DMP
line and press NL.
STAFFENGLIBRARY7100_PAIRWISE.
Contact your IS information manager and
pathname of the directory that contains
programs in your installation.
obtain the
PAIRWISE
the
We recommend that you invoke IS from your personal
information area.
Therefore it is necessary to
create an IS drawer and folder with appropriate
attributes to hold the files created by PAIRWISE.
Log on to IS and execute the following
steps
1
2
.
4
5
6
7
8
From IS MAIN
press NL.
From FILING
and
MENU
FUNCTIONS
2.
Filing and
select
1.
Drawers
press NL.
From. the DRAWERS
and press NL.
Type
select
in
the
and
press
For
NL.
Change
submenu
name of
the
select
drawer
NL.
Attributes
3.
Create
7100 PAIRWISE
type Y and
press
Change maximum size type Y and press
maximum size of
Type in the appropriate
drawer press NL and press the EXECUTE
function key Fl.
Each PAIRWISE
problem can
take up to 100 blocks
on the amount
depending
of information it contains.
For
NL.
the
For Change
press NL.
other user
For Change
press NL.
drawer
20
access
type N and
searchlist type
Y
and
9
10
From the
and
submenu
press
select
12
13
the
EXECUTE
From the
19
PAIRWISE.
select
Continue
3.
function
key
Fl
and
twice.
function key F1l
Press the CANCEL/EXIT
submenu and
twice to return to the DRAWERS
create a folder that will contain the PAIRWISE
files.
Select size appropriately.
15
18
PAIRWISE
Press
From the DRAWERS
17
INVOKING
From the submenu
press NL.
14
16
Searchlist
to
Type in the full pathname for the PAIRWISE
directory and press NL for example
STAFFENGLIBRARY7100
11
Add
1.
NL.
and
and
press NL.
FOLDERS
press NL.
Type in the
press NL.
For Change
name
folder
submenu
select
1.
Folders
submenu
select
3.
Create
of
the
folder
size type
Y
PAIRWISE
and
and
press
NL.
Type in the appropriate
press NL and press the
key Fl.
size for this folder
EXECUTE function
Press SHIFT/.CONTROL/F1
to return to
MENU and follow the instructions in
PAIRWISE.
MAIN
Invoking
IS
you invoke PAIRWISE you should create a
and folder in your personal information
Follow the instructions in the previous
area.
In subsequent PAIRWISE
sessions execute
section.
the following
steps
Before
drawer
1
2
3
From IS MAIN MENU select
Information and press NL.
From the Level
and press NL.
Type in the
press NL.
submenu
name of
21
the
1.
Access
select
PAIRWISE
4.
Personal
drawer
and
4
5
6
Type in the
press NL.
Enter
name of
PAIRWISE
in
the
the
IS
PAIRWISE
command
folder
and
line and
NL.
After exiting PAIRWISE press
function key to return to the
press
the
CANCEL/EXIT
IS MAIN MENU.
the
following
you failed to access PAIRWISE
instructions above contact the IS information
The PAIRWISE
manager for your staff.
programs are
he directory you named in
in the
probably not available
the
searchlist for your PAIRWISE
drawer.
If
A few variations over the scheme outlined above are
You could for instance have your
possible.
PAIRWISE
files in the staff information area or
Whatever
is the
access other users files.
situation make sure you have edit permission for
the IS drawer you access.
All files created under PAIRWISE
in the
IS folder.
These
objects
files
PRINTING
PAIRWISE
a
REPORT
will show
are
the
as
types
of
Problem ID.PRW
Contains
Problem ID.PRW.BU
Contains PAIRWISE
data before
the last editing session.
You can delete any of this
file without
loss of
essential data.
Problem ID.WRD
Contains PAIRWISE
Report.
These files have to be
imported into CEO before the
They
report can be printed.
can be deleted without
loss
information.
of essential
$PAIRWISE.DEFAULT
Contains PAIRWISE
default
information for a particular
This file can be
user.
deleted without
loss of
essential information.
PAIRWISE
data.
docu-ment.
The
PAIRWISE
a report file
print function generates
CEO format.
This file must be imported into
CEO and can be treated as any other CEO
The report file already includes headers and
footers and can be printed immediately after
in
a
22
Follow the following
instructions
importing.
transfer the report file into CEO
1
2
3
4
5
6
7
8
9
Access
in
PAIRWISE
according
PAIRWISE.
the
to
to
instructions
Invoking
Print
ID.
a
PAIRWISE
report for
selected
a
Problem
Exit PAIRWISE.
Enter
CEO
in
the
IS
command
line and
NL.
From CEOs MAIN
press NL.
MENU
select
From Filing Functions
press NL.
For Filename
press
the
appropriate
7.
Filing and
Import
enter
Problem ID.WRD
entries
in Filing Menu
NL.
Fill out
select
S.
drawer
folder
press
and
and
with
and document
Enter the summary information for the new
document and return to CEOs Main Menu.
23
the
names.
Heart Bar Hybrid Photovoltaic
System
Audie Nishida
Civil Engineer
San Bernardino
Forest
Robert Ota
Civil Engineer
San Bernardino
National
Forest
National
Joe Olson
Civil Engineer
Regional Office
5
Region
INTRODUCTION
sys-tems
hybrid
Region
photo-voltaic-generator
remote stations where
systems
Two
5
Forests
have
installed
at
commercial electricity is not available.
The
are at Heart Bar Station on the San Bernardino
Station on the Los
National Forest and at Nacimiento
This article is a report on
Padres National Forest.
the Heart Bar installation.
HYBRID SYSTEMS
A hybrid system combines
a
photovoltaic
generation
engine-driven
system with a conventional
generator
resulting in a system with some very desirable
the generator can be smaller than it
would be without
the photovoltaics
if the battery
bank is sized to carry short-term peak loads and
if it were
the
it runs far fewer
hours than it would
sole source of power.
When the generator does run
Because
it does so efficiently at near-fu.ll load.
the generator
few hours the time
runs comparatively
is longer
or overhaul
period between replacement
than with a conventional
Because routine
system.
repairs can be scheduled for periods when sunny
weather is expected
a backup
generator is not
normally required and the generator is available
when the photovoltaic
system is being serviced or
is inoperative
for any reason.
char-acteristics
run-ning
A hybrid system makes electricity available 24 hours
a day without
the inefficiency of a generator
the constant
under light load and without
noise of a generator.
A hybrid system does however
have some very
The initial cost is very high
serious drawbacks.
25
bat-teries
because of the high costs of photovoltaic
panels and
is that the
batteries.
Another disadvantage
must be replaced approximately
every 5 years.
and changing very
Photovoltaic
is new
technology
are fully up
rapidly.
Few designers or contractors
to
to date so the time from inception of a project
usually is much longer
completion of construction
system.
than for a conventional
HEART BAR
STATION
year-round.
Heart Bar station is located in a remote site and
consists of an office
barracks and two residences.
The station is intended to be occupied and used
A 17.5-kilowatt diesel-fueled
generator
previously provided the electricity to the station.
The generator was acquired as military surplus and
and costly repairs.
required constant maintenance
administration
Contract preparation
and contract
Audie
were provided by Robert Ota and
Nishida Civil
Forest.
The
Engineers on the San Bernardino National
contract
was awarded to Henry Radio of Los Angeles
Work began in summer 1985 and
at a cost of $38054.
consisted
The contract
was completed in May 1986.
of furnishing and installing a complete
photovoltaic
with a 10-kilowatt
system to be used in conjunction
The
Onan generator installed by the Forest Service.
18-foot
a 12Forest Service also constructed
by
wood-frame building to house all photovoltaic
and the
generator figures 1 and 2.
equip-ment
opera-tion
schematic diagram in figure 3 shows the
When the sun shines
of the Heart Bar system.
make up the
on 40 Arco Solar M53 panels which
photovoltaic
array number 1 on the diagram each
panel produces a nominal 43 watts peak at
17 volts.
A Photron PP-20-LC Photovoltaic
Source Combiner number 4 on the diagram combines
into a nominal 1680 watts peak at a
the output
The electricity then is routed
nominal 48 volts.
to the
batteries
through a Photron Source Center
The source center serves as an interconnection
as well
components
center for all direct current
and overcurrent
as a main DC disconnect
protection
device.
It
also allows for simplified photovoltaic
array testing and isolation of failed modules within
The
approxi-mately
5
7.
the
DC
array.
lead-antimony
7
Energy is stored in 24
batteries
Battery
Engineering.
26
2-volt
heavy-duty
manufactured
by Industrial
The batteries store enough
Figure 1.--Heart Bar building exterior
showing photovoltaic
panels on roof.
unaccept-able
energy for approximately
drawdown.
8
2
days use without
The 48-volt direct current arriving at a Westec
W500-48
volts
inverter
is converted
to 120/240
for use in the
alternating current
administrative
site.
AC
3
The control enclosure
contains several components
that monitor the system and provide appropriate
indicators
a Photron BVR-50
responses to various
Photron
a
a
Battery Voltage Regulator
Photron Gen Wizard and a generator exercise timer.
Brain
27
h
h
n
..
R
l
Figure
on
2.-
Building
interior.
Batteries
on
left
generator
right.
The
Photron battery voltage regulator regulates the
voltage supplied to the batteries and disconnects
the photovoltaic
panels when the batteries are fully
It
also disconnects
the batteries from the
charged.
photovoltaic
panels when no output is available from
the panels
for example at night thus preventing
battery discharge through the array that would
otherwise occur.
indi-cating
The
PhotronBrain
When the
senses battery voltage.
voltage drops to a critical level
that charging is needed
a signal is sent to
the
Photron Gen Wizard which converts the Brains
two-wire system to the Onan generators three-wire
This happens
start system and starts the generator.
during prolonged
cloudy weather or whenever the
daily output of the photovoltaic
array cannot keep
The
up with the daily consumption of electricity.
brain also stops the generator when the batteries
have been fully charged.
battery
The
exercise timer automatically starts and
for an hour or so every week.
generator
28
runs the
------------------2
DOý00 O
O
CO7OC_CCý70Cý0
I
_-n-tr-o-l
I
Control
Control
L1
cl
48
VDC
48
VDC
O
5
48
x
ti
48
VDC
VDC
g
olf
120/240
VAC
120/240
120/240
Ol
P.V.
O1
Generator
O3
Control
Figure
Array
Enclosure
PV
Source
Controller
DC
Source
Center
3.--Heart Bar photovoltaic
VAC
VAC
O6
Battery
O1
Batteries
O
Charger
Inverter
Transfer
system schematic
Switch
diagram.
The generator is an Onan 10-kilowatt model fueled by
It charges the batteries
liquefied petroleum gas.
which is
by means of a Photron Gencharger
similar to many large commercial battery chargers.
6
9.
automati-cally
The generator also is connected
to the Photron
Tranzac
transfer switch
This switch
transfers loads directly to the generator
whenever it is running and returns the loads to
29
the
batteries and inverter as soon as the generator
The switch also can be used in a manual
stops.
A hybrid
voltaic
size.
because
mode.
photo-array
system
At
of
ideally is
a
balance
between
size battery bank size and generator
Heart Bar this balance was compromised
The
the amount of money available.
battery bank is large enough to provide 2 days
storage for current needs but there are only enough
photovoltaic
panels to provide 8.6 kilowatthours of
the total 10.4 kilowatthours
of current daily
Additional panels could be added to
increase the systems daily output with no
but for now there is a
to other components
in
the
shortfall
photovoltaic
slight
panels output.
It
is not yet known
exactly how much generator time
will be needed a preliminary estimate is an average
of a half-hour per day.
con-sumption.
modifi-cations
ECONOMIC
ANALYSIS
The system was constructed.
under the Federal
Photovoltaic
Utilization Program which was intended
to demonstrate
the technical feasibility of
but not necessarily economic
feasibility.
No economic
before
construction.
made
was
analysis
The accompanying
was made after
analysis figure
results
with
rather
surprising
construction
the high initial costs of the photovoltaic
system and the current low costs of diesel fuel and
photo-voltaics
consid-ering
4
liquefied
petroleum
The
gas.
total present worth of the conventional
system
just slightly less than that of the photovoltaic
The photovoltaic
system.
system cannot be justified
the
basis
of
but perhaps it
on
economics
strictly
because of its other
might still be appropriate
advantages such as less noise and 24.-hour-per-day
availability of electricity.
is
30
Analysis of
Economic
Life
project
of
Present
Worth
Bar
System Versus
Hybrid
Generator-Only
System
25
Rate
Discount
Heart
years
percent
7
prescribed
as
PWF
Factors
for
fuels
energy-related projects.
determined by Department of
for
as
Energy
November
1985.
Maintenance
costs
for both
and
hybrid
and
are therefore
approximately equal
not
included
in
this
estimated
are
to
be
comparison.
System
Hybrid
Construction
Cost
Cost
generator-only systems
of
10
kW
of
PY
System
8400
4500
$38054
$
$
Contract
First Cost
Total
Replace
Force Account
Building
Generator
of
batteries
every
years
installation
5
$4224 materials
$51000
$4700
$420
Present
Year
5
10
15
20
Total
Cost
PWF
Worth
$4700
$4700
$4700
$4700
0.7130
0.3624
0.2584
$3351
$2389
$1703
$1214
of
replacement
Present
0.5083
Worth
battery
replacement or
generator will need
project
say at year 12.
major overhaul
The
$4500
Fuel
x
0.444
PWF
is
estimated
Cost
2.75
of
Total
Life
Construct
of
Cycle
of
Cost
to
an
of
average
a
half-hour
hr/yr
x
$0.72/gal
$362/year
$362
liquefied petroleum gas
of
Hybrid System
building to house
generator
per
day
the
year-round.
rounded
to
x
$5700
15.88
nearest
$1000
$67000
$6500
$5000
generator
10
every
years
Present
Worth
Cost
PWF
10
20
Total
$5000
$5000
0.5083
$2542
0.2584
$1 292
of Generator 4eplacement
Worth
Present
Value
at
year
$5000/2
25
-$500
Cost
12 kW
8 hr/day
Present
Life
x
365
Worth
Cycle
days/yr
of
Cost
diesel
of
analysis
1.2
x
gal/hr
to 900
AM
1.2 gal/hr
fuel
fuel
and
consumption
500
System
generator-only system
made
PM
to
to
nearest
is
after construction.
31
1000
PM
$3048/yr
$0.87/gal
x 16.77
x
$3048
Generator-only
life
cost
of the
cycle
of the
hybrid
system.
4.--Economic
$3800
0.1842
x
diesel
generator
600 AM
Estimated
use
Figure
run
12kW
PW
that
of
$2000
Year
Salvage
The
life
System
generator
Replace
183
x
Worth
Generator-Only
Total
the
during
LPG
gal/hr
Present
Fuel
once
Costs
Generator
Cost
$8700
daily
$51100
$1000
approximately
$66000
2
percent
less
than
Hume Lake Dam-First
Concrete M u ltiarch Dam in the United
Rehabilitation of
States
Darrel
Special
Sequoia
Region
INTRODUCTION
HISTORY
Cherry
Project Engineer
National
Forest
B.
5
For-est.
Com-pany
Hume Lake Dam built in 1908 was the first concrete
multiarch dam in the United States.
The lake is the
most heavily used lake on the Sequoia
National
Recreation the primary use serves a large
of people. The dam needed renovation
population
to
preserve its life and structural integrity so that
the
lake and recreational
uses could continue.
dam originally designed and constructed by John
Eastwood in 1908 for the Hume-Bennet Lumber
was used for the harvest of the giant sequoia
redwood trees.
It is now considered
the
last remnant
of that era.
The sawmill constructed
directly below
the dam used the
lake as the millpond.
A
flume floated the sawed boards to
V-shaped
Sanger California the nearest railhead.
The
S.
67-mile-long
87-acre lake has a 1411 acre-feet capacity.
dam is 51 feet high and 677 feet long including
the wing walls.
It has 12 arches each having
a
The dam had three
50-footspan and 13 buttresses.
outlets--a 24-inch outlet at the lowest point in
arch 6 for draining the lake a 12-inch outlet about
10 feet higher
in elevation in arch 5 to supply
water to the mill and flume and a 12-inch outlet in
arch 4 to supply water to the mill and flume.
The
main spillway comprised twelve 5-foot by 8-foot
windows in arches 5 6 and 7 with flashboards
for
raising and lowering the lake level water also
could flow over the top of arches 4 5 6 7 8 and
9.
It took 114 days to construct
the dam which
cost $46000.
The
The
Figure 1 shows the dam and part of the constructed
mill just after completion in 1908.
Figures 2 and
show plan and elevation views and typical cross
sections
of the dam.
33
3
Figure 1.--Completed dam
in
1908.
In 1917 the sawmill burned down and was not rebuilt
in its original location.
In 1935
because of
declining logging industry the area became National
Forest land.
1949 INSPECTIONS
deteriora-tion
inspections found serious
concrete around the window spillways.
As a result sometime in the 1940s the windows were
plugged with concrete leaving only a shallow
over the top of arches 4 5 6 7 8 and 9 for
a depth of 1 foot
before water flows over the entire
length of the dam.
spill-way
Subsequent
of
dam
the
pro-gressive
1949
the inspections
also indicated some
foundation leakage in arches 9 10 11 and
12.
Leakage through the dam itself also was
Water overflowing
arches
increasing.
2 3 and
12 was eroding the foundation
on the backside
of the
In
1
dam.
34
12
East
Wing
10
11
39_
8
01
9
6
7
4
so
Wall
3
2
0c
West
PLAN
5300
E1.
ma
2
West
Wing
5299
El.
No
3
4
E1.
7
6
Wing
5300
East
5300
El.
12
E1.
10
1
8
g
E1
5299
4
5
5300
3
2
Wall
West
Elevation
Figure 2.--Plan
and
elevation
views
of
Walt
Wing
Downstream
6
7
Wall
1
Wall
Elevation Looking
East
9
Wing
Looking.
Wing
Wa11
Upstream
dam.
In 1954 because
of these findings
a contract
was
awarded to Ted Schwartz for $64905 to repair the
dam.
The work consisted of the following
items
1
2
3
4
5
Foundation
Placing
steel on
inches of gunite with
upstream face.
the
reinforcing
Placing a 2-foot concrete
high parapet
top of arches 1 10 11 and 12..
Plugging the
concrete.
Repairing the
arches 5 and
Figure
before
1978 INSPECTIONS
6
grouting.
4
shows
the
12-inch
outlet
in
arch
outlet
valves
and trash
4
wall on
with
racks
in
6.
sample of the condition
guniting process in 1954.
a
of
the
dam
Special-ist.
In
dam
1
1978 under
the National
Dam Safety Program
was again inspected by a Regional Office
The following were inspections
concerns
Questionable
spillway capacity.
35
the
21
El
5299
2
13
6
.
1
16.
3
115.9
19.7
20.4
4
1j
Variable
To
24
50
\
0.45
1
1
24
1
\\ýýg
\ 0.64
0.40
0.64
111\
\\
0.56
\
1
Approx.
Typical
Buttress
Looking
Typical
Upstream
At
Max.
Ground
Line
Arch and Buttress
Section Arches 4 to
25
E
25
Rsý
rr
Plan
Arch
Figure
3.--Typical
sections
of
2g.5
-- ------
Typical
and
Buttress
of
the
dam.
36
I
8
1
Figure
2
3
4
5
4.--Arch
l
before
Inoperable
24-inch
Foundation
seepage.
Questionable
activity.
application
gunite
valve
capacity
Recommendations
for
a
to
in
in
1954.
arch
6.
withstand
Phase
I
and
seismic
II
investigation.
The Army Corps of Engineers
conducted
the Phase I
and found that the maximum probable
investigation
flood MPF would overtop the spillway crest of
dam by 5.5 feet for a 4Z-hour period and by 2 feet
during a flood equal to half the MPF.
1979theForest
Leeds Hill and
awarded an A
E contract
for $42493 to make a
Phase II investigation
and safety evaluation
of Hume
Lake Dam.
The contract
included a study an
and a pseudostatic
analysis to evaluate the
structural safety of the dam.
In
to
Service
Jewett
Inc.
investi-gation
37
The results of the pseudostatic
analysis indicated
that portions of the dam could be overstressed when
were acting parallel to
the
earthquake accelerations
Tensile
stresses also could
the axis of the dam.
develop between the buttresses and foundation which
or
conditions could overturn
under earthquake
the buttresses.
col-lapse
Cate-gory
crit-ica
into
The contractor divided
the recommendations
three categories
Category I those measures that
to its
would restore the dam and its appurtenances
original condition and structural integrity
II work that would increase the structural
strength of the dam to enable it to withstand
loadings and Category III those
earthquake
but were not
measures that should be considered
recommendations
are
Individual
remedial
mandatory.
the
limitations
because
of
listed below.
However
seismic
of the pseudostatic
analysis in predicting
was
loadings additional dynamic analysis
such as a time-history finite element
recom-mended
analysis.
1
Category
a
b
c
d
2
replace the 24-inch outlet to
and to prevent
emergency drawdown
overtopping of the dam.
Repair
enable
or
face of
the downstream
Resurface
concrete
with
and the buttresses
deterioration.
prevent continued
the dam
to
Grout the foundation
at the upstream toe
dam
in
arches
of the
8 9 and 10 and
beneath
buttresses 1 2 10 and 11.
Repair any cracks on the upstream face of
the dam that are visible after the lake is
drained.
Category
a
b
I.
II.
Reinforce the arches
tension stresses.
to
avoid
excessive
side-sway
Reinforce the buttresses to prevent
or collapse
and possible overturning
of the buttresses.
38
3
Category
a
b
c
d
III.
Raise the ends
overflow would
portion
of
the
of the dam to ensure the MPF
be confined
to the center
dam.
Remove all vegetation
and brush
downstream
side of the dam.
Remove
water pools
downstream
face of
Monitor
seepage
at the toe
the dam.
through
the
of
on
the
the
foundation.
Con-sultants
eval-uate
recommendation
of Leeds Hill $ Jewett
contract
was awarded to Converse
for $59869 to conduct
a seismic dynamic
to
were
analysis.
They
perform the analysis
the results and report their findings with
recommendations as to any structural corrections
needed.
Following
another A
the
f
E
Consultants reevaluated Hume Lake Dam by
a series of stress analyses of a
conducting
finite element 3-D FEM model of the
the
static and dynamic
dam.
The analyses determined
the
and
the stress
of
the
dam
deformations
response
distributions in the dam under the design Maximum
Credible Earthquake
MCE loadin Richter Magnitude
8.25 at Owens
Valley California.
Converse
three-dimensional
condi-tions.
analyzed the dam assuming full reservoir
The dynamic loads included cross-valley
upstream-downstream and vertical time histories of
motion.
The maximum combined stresses included full
reservoir static loads 10
temperature changes
and dynamic loading these combined stresses did not
exceed the strength of the concrete.
A sample of
the stresses developed
are shown
in figures 5 6
and
7.
that Hume Lake Dam would
They concluded
when subjected to an earthquake
perform adequately
with similar characteristics.
They
F
Converse Consultants recommended
the Category I
remedial corrective
measures as stated by Leeds
Hill $ Jewett.
Since the stresses in the dam did
not exceed the strength of the concrete Category II
corrective measures were not necessary.
fI
39
100
cullll.ýE1111YiýYtJýp-r17
ýýIýT.ý
.nya.
75
0
50
LOCATION
KEY
25
w
w
0
Wce
-25
Z
-50
0
C
-75
-100
0
5
10
20
15
25
30
TIME
Figure
5.--Cantilever
REHABILITATION
in 1984
stress history of
35
40
45
50
55
60
seconds
upstream
element.
The
Corps of Engineers provided consulting services
during the contract
and during
the
development
grouting and shotcreting processes to train Forest
Service inspectors.
A contract
to rehabilitate
the dam was awarded to
Dennis
Seevers.
ALL-CON
The work was performed
during the summer of 1984.
Total construction
cost
was $448152.
The contract
items of work included
were
1
as
follows
Foundation
Grouting.
Grouting was done at the
upstream toe of arches 8 9 10 and ll.
Drilling depth ranged from 10 to 30 feet
Grouting pressures varied from 5 to 20 psi
on the depth of the hole.
depending
40
5245
ýýIfinfTFý.j1t_EFi3T3.TmT
STRESSNegative
5250
KEY
at
22.68
seconds.-.
STRESS
5255
127
.19
each
of
at
the
plus
dynamic
stresses
-1r3
r_IS4
t-67
9197
-36
-3417
-393
Compression
_25
z2o
-t32
-6o
-r222
szt
CANTILEVER
08
Tension
5260
55
-
ý
-3
99
dynamicstresses
-127
_ý
-91
and
of
sum
the
element.LOCATION
$265
-35
107
2
147
20
ý
ARCH
-87
ore
shown
cantileverstresses
-35.14-209-406
-n
694
134
-2T
-9
in
psi
given
Arab
-1
3.
and
All
are
t
2.
static
5285
f5
l07
119
.
_e
-IS
MCE
1.
center
21
117
12
12e
63
49
ez
60
--70
r
31
NOTES
Maimumcredibleearthquake
-
5290
-40
99
101
72
46
173
130
27
170
_34
126
t94
TI
t-49
t-13
43
-t4
Y-62
e2
f
x-90
reservoirelevation5299.0.
-III
t-37
_$295
12
40
tS
-190
III
--30
tM
105
90
104
15
94
47
IS
11
31
19
IS
35
117
-49
61
ee
t
stressvalues
7-F5
73
t7U
50
70
--$3
73
-91
71
6T
e
40
91
14
-60
67
t20
s2
117
74
53
76 -2
46
Positive
-t
5300
13
B
1
S
12
-4
-4
9
S
1
B
13
-60
14
tN
97
103
49 99
SO
53
45
t-9
77 41
32
6.--Static
ITT
downstream
Looking
FACE
UPSTREAM
OF
VIEW
N
-S
ý-95
44
ITS
76
-
I
S
It
17
21 t67
21 e7
-1
Figure
ELEVATIONPROJECTED
Maximum
Stresses
Static
-
Plus Dynamic
Loads
Cantilever
Compression
120
psi
at
12.44
sec.
225
psi
at
22.68
sec.
Cantilever
Tension
406 psi
at
22.68
sec.
168
psi
at
22.68
sec.
Arch
Compression
237
psi
at
22.68
sec.
211
psi
at
22.68
sec.
Arch
Tension
209
psi
at
22.68
sec.
175
psi
at
22.68
sec.
Figure
7.--Maximum stresses
2
3
4
5
6
on
the
dam.
con-crete
Shotcrete.
This consisted of cleaning the
surface on the downstream
face placing
steel wire fabric
and applying
6x6x6 welded
inches of shotcrete.
3
The inlet structure consisted
Inlet Structure.
of a trash
rack with an antivortex plate a
inlet pipe a 36-inch steel
54-inch vertical
pipe through the dam a 36- and a 12-inch ball
valve an electric remote operator for the
36-inch valve and a 22-inch vacuum release
See figure 8 for more details.
pipe with valve.
Upstream
chipped
Crack
out
Repair.
cleaned
Cracks upstream
and shotcreted.
were
milli-meters
Waterproof
144
of a
on the
Membrane.
They sprayed 16
coating
polymer cementitious
upstream face of the dam.
Sika
Seepage Tubes.
They placed small seepage tubes
in known water-bearing
cracks on the downstream
pro-ject
face.
on the
the.biggest problems encountered
was the poor placement and holding ability of
the cofferdam.
The silt and debris in the bottom of
the
lake was worse than expected at the base of the
dam and the earth-filled cofferdam continually
The
leaked and sloughed off into the working area.
cofferdam
eventually failed making the job even
it was
more difficult. Because of this condition
to a
necessary to redesign the inlet structure
vertical inlet pipe.
One
of
42
36
Anti-Vortex Plate
Trash
12
Ball
Valve
Electric
Operator
54ý
8
ý\\
Mud
Level
Cofferdam
Release
Valve
Rack
o
Vacuum
Ball
After
Failure
I
I
9.
12
Pipe
I
._ýo.ý
.
A.
36
12
7/ýýGranito
Figure 8.--Pipe
Side
inlet
structure
View
and
Top
View
valves.
founda-tion
We
also found more weathered
bedrock
in the
than expected.
The weathered
bedrock
located
in arches 1 2 3
4 9 10 11 and 12 resulted in
another contract
with Converse Consultants for
$23238 to check the foundation more fully and
reevaulate
their previous analyses.
We wanted to be
sure the structure was still safe since they had
assumed in their original analysis that the
and concrete
were rigidly connected.
They
that the distributed combined stresses did
not exceed the strength of the concrete
in the dam
and considered
the dam to be safe.
founda-tion
con-cluded
FINAL RESULTS
Based on the recommendations of Converse
Consultants
we are monitoring foundation
seepage in arches 1 2
3 4 9 10 11 and 12 to detect any increased
seepage through the weathered
bedrock.
We also have
surveyed control stations on top of the dam so we
can measure and record any horizontal or vertical
movement
of the dam.
43
Leakage through the dam itself is minimal
seepage tubes are functioning as designed
more weep tubes would have been better.
and
the
although
valve fully open we
Even with the vacuum-release
and dynamic
that
cavitation
still have some concern
is
when
the
36-inch
valve
surges may be taking place
controlled
not
This is being
opening
by
fully open.
the valve fully for any long durations and by
the 36-inch
valve only until a vacuum just
begins to develop approximately 80- to 85-percent
We expected no problem because the 36-inch
open.
valve will be fully open only during emergency
As a
drawdown and then only for a short duration.
of
the
the
interior
precaution we will inspect
the
inlet structure
for a
inlet pipe after operating
few years.
open-ing
44
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