Keeping Mapping Data Current on Long Duration Projects

James H. Anspach, P.G.

Project Manager (2003-2008) Utility Mapping

Alaska Way Viaduct Project, Seattle, WA

Project DetailsAbout 110,000 vehicles use the viaduct each day. The viaduct is 2.1 miles long. The existing structure has an overall width of 51 feet (near Madison Street).

Original Mapping Scope of Work

All utilities at QL B when possible

Access every structure Direct Connections Depths of all pipes,

cables, conduits Sizes of all pipes,

cables, conduits Description of utility

endpoints

Entered every basement

Conductor inserted into every empty conduit

Pipe & Cable Locators, GPR, Elastic Wave, Magnetic, Terrain Conductivity all used

Every cable/conduit tracked down, accounted for, and marked

Results

• 8+ miles of city streets averaging 20+ conductors = 1,000,000 feet of utilities +/-

• 7 year effort as areas of interest expanded due to geotechnical and utility issues

• Entered over 1000 communication and electric vaults and documented contents

Problem: How to keep utility data current

Extensive construction by City for IT conduits, security cameras.

Numerous building projects changing/adding service connections

Normal improvements with 8+ miles of City streets

Extensive communication work near stadiums

Advance utility relocation work taking place

Procedures on a yearly basis

• Walk entire project limits with existing utility mapping in hand– Check every utility pole for new risers and/or

new appurtenances/attachments

– Look for “new” street patches (on first update, sketched all patches on plans for future comparison)

– Look for ongoing long-duration construction projects

• Aquarium, Art Museum, Stadium district, new roads

Procedures on a yearly basis

Research Permits issued by the City within previous year If it appeared as if work could involve any

utility work (new, abandoned, removed, replaced), re-designate area.

Ask all utility owners (including different City Departments) for any new records within the past year Re-designate areas where utility changes

from records Research all one-call tickets within project

limits for previous year If appeared to be utility related, re-

designate area

ISSUE: How do you communicate any changes to the mapping to the 200+ persons

using that data?

• AutoCADD file with area of any changes “clouded” (outline and translucent mask)

• New utilities in bold thick line style• Note (text box) with call-out arrow• Accompanying WORD text document• Second AutoCADD file with all changes

“accepted” in normal line codes, colors, and with call-outs and clouds removed.

Level of effort Depended upon amount of changes, but on average:

40 hours for reviewing One-Call tickets for applicability in the office

40 hours for walking project with plans in hand 40 hours for researching new permits 80-120 crew hours for designating, surveying any changes 60 hours CADD and professional review and engineer’s

“seal” of final results About 5% of initial effort

If not done annually, quality suffers and percentage of time increases.