Applying Subsurface Utility Engineering to Highway and Road Projects

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Applying Subsurface Utility Engineeringto
Highway and Road Projects
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Existing Underground Utilities are the Veins and
Arteries of our Cities and Roads

• And yet, we know very little about where they are

Communication Gas / Propane Petroleum Sewerage Dra
inage Power Steam Water
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WHY?
We keep adding and changing utilities

• Expansion
• Modernization
• Changing Utility Technology
• Changing Facility Missions

We dont keep good records

• Referenced to changed topo features
• No centralized records storage
• No standard format
• No responsibility

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Where do we get Utility Info?

• Old Project Plans (As-Designed)
• Old Project Plans (Red-Lined)

• Utility Records (As-Designed)
• Utility Records (As-Built)

• Maintenance Records
• Repair Records

• Visual Observation
• Field Survey

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The Engineer uses these sources to compile a
utility composite that overlays the new design
Nowadays, we frequently digitize this data into a
CADD or GIS System
This can result in even more errors
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The Engineer ends up with utility data of unknown
reliability
I think the gas line is here, but Im not really
sure. It might be in conflict with this proposed
piling.
This makes it extremely difficult to manage the
risks that are created by existing underground
utilities
I guess well let the contractor worry about that
!
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What are these Risks?
Utility Damages Affecting the Safety
of Construction crews, or the Public
The Telecommunications and other industries
recognize this
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There are a lot of other risks too

• Redesign costs
• Higher construction bids
• Change orders
• Extra work orders
• Construction Claims
• Higher insurance costs
• Higher financing costs

• Project delays
• Detours

TIME

• Bad publicity

Intangibles
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Fortunately, theres a way to handle this risk

• SUBSURFACE UTILITY ENGINEERING

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S.U.E. Combines Traditional Engineering
Practices, such as ..
Utility Records Research
Relocation Cost Estimates
Utility Design/Relocation Design
Plotting of Utilities from Records
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with New Technologies
Utility Designating via Surface Geophysical
Methods
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Utility Locating Via Non-Destructive Vacuum
Exposure
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The Most Significant Advancement is the Utility
Quality Level Attribute
Quality Level Attributes are attached to plotted
utilities
They indicate how utility data was developed
Reliability and Accountability are defined
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Quality Level D
The least reliable utility data

• Plotted on plans from records.
• Sometimes a field visit - to look for utility
  indications on the site - is made.
• Sometimes verbal recollections are plotted.

This level of effort is great for Project
Planning purposes, utility inventories, and
very preliminary utility relocation cost estimates
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Quality Level C
The traditional utility depiction

• Surface Appurtenances are surveyed and accurately
  plotted on a current site plan
• Utility data from records (QL D) are correlated
  to the appurtenances

Problems with records interpretations still
exist e.g. schematics, no appurtenances
depicted, utilities not straight between
appurtenances, no records exist, and so on.
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Quality Level B
A significant upgrade in quality

• Surface Geophysical Methods used to search for
  and trace existing utilities.
• Designated utilities are then surveyed and
  plotted on site plan.

Non-recorded utilities found. Utilities routes
between appurtenances are imaged. Typically
used in early preliminary design for construction
footprint decisions.
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Quality Level A
A guarantee in 3-D

• Utilities exposed via non-destructive air-vacuum
  means
• Exposed utilities are then surveyed and plotted
  on site plan Elevations, Size, Condition,
  Materials, Precise Horizontal Positions are
  measured and documented

Typically used in final design stages. Allows
small adjustments in design for big savings in
construction
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QL A and QL B upgrades have been successful in
reducing risk on tens of thousands of highway and
road projects.This is a tried and
trueprocess
Used extensively by Eastern State
DOTs Municipalities
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SUE has an Outstanding Record
Under recent contracts with various departments
of transportation including the Texas DOT, New
Jersey DOT, North Carolina DOT, Virginia DOT,
Pennsylvania DOT, Delaware DOT, Ohio DOT,
Georgia DOT, Florida DOT, Arizona DOT, and the
Maryland State Highway Administration, This
represents tens of thousands of separate
projects, some of which involved over 200,000
feet of utilities (Quality Level B) and 850 test
holes (Quality Level A).
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Yet, SUE has not been used as a professional
standard practice in some areas for many reasons.

• No concerted local or regional effort to educate
  project owners or engineers of benefits
• Lack of interest by state DOTs
• Development of SUE has been primarily on the east
  coast
• Few national providers
• Combined construction values in some areas lower
  than in others
• Lack of a well defined standard of care created
  little incentive for changing the status-quo

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These Impediments to SUE are rapidly disappearing
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There are now national standards under
developmentAmerican Society of Civil Engineer /
American National Standards InstitutesNational
Standard Activity
This will redefine the standard of care for
utility mapping by the engineering profession
Standard Guidelines for the Collection and
Depiction of Existing Subsurface Utility Data
With an anticipated publish date of December 2001
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A January 2000 FHWA / Purdue University study
(Publication No. FHWA-IF-00-014) states the
following A savings of 4.62 for every 1.00
spent on SUE was quantified from a total of 71
projects. These projects had a combined
construction value in excess of 1 billion. The
costs of obtaining Quality Level B (QL B) and
Quality Level A (QL A) data on these 71
projects were less than 0.5 percent of the total
construction costs, and it resulted in a
construction savings of 1.9 percent over
traditional Quality Level C (QL C) and/or Quality
Level D (QL D) data. .62 for every 1.00 spent
on SUE
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One individual project had a 206.00 to 1.00
return on investment (North Carolina DOT). Only 3
of 71 projects had a negative return on
investment. The simple conclusion of this study
is that SUE is a viable technologic practice that
reduces project costs related to the risks
associated with existing subsurface utilities
and, when used in a systematic manner, will
result in significant quantifiable and
qualitative benefits.
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And theres more!SUE is recognized as aBEST
PRACTICEby

• AASHTO
• Federal Highway Administration
• Associated General Contractors
• Office of Pipeline Safety
• National Transportation Safety Board
• Network Reliability Council
• Many state DOTs

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SUE offers a One-Stop Shop for all of a projects
utility needs
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A SUE Provider has the Diverse Experienced
Staff necessary for these services
Field SUE Specialists Field SUE
Technicians Survey Party Chiefs
Highway Designers Utility Design Experts Utility
Accommodation Policy Experts
Professional Engineers Professional
Surveyors Professional Geologists
Records Researchers CADD Technicians Utility
Engineers
Equipment Repair Techs Air/Vacuum
Fabrication Vehicle Maintenance
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Subsurface Utility Engineering offers tremendous
value for your projects, too
With a mix of field and office activities
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Field survey of utility appurtenances,
designating, and locating data
Utility designating via surface geophysical
techniques
Utility locating via non-destructive vacuum
exposure
Utility mapping using quality level attributes
Utility Conflict avoidance advice and design
Utility design and relocation design
Utility relocation coordination
Relocation cost estimates
Utility records research
Utility easement plats
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Slide show and pictures courtesy of So-Deep, Inc.