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FHWA Unknown Foundations Summit

Unknown Foundations Synthesis Review
Scott Sabol, consultant and professor at Vermont Technical College

Project Objectives
Report on technologies and methods; business decision making practices related to Ufs suggest areas for research and development

Analogy: Scott Sabol bought a house, but didn't know about septic tank. Found builders, didn't know. Called S-tank cleaner (technology), tried chase pipes. Another technology. Business decision was "is it worth ignoring – the tank was worked in the past": – Final decision was to use the most expensive technology to find it.

These are thought processes: what are technologies, ramifications, who to talk to.

Key aspects:
Define problem
Collect info
Serve as channel for those who have worked on or are working on problem
Present findings in useful format of various audiences: executives, operations.

Project schedule
Start September 15, 2005
End September 14, 2006

Kick off meeting with FHWA
Characterize UF population
Literature review
Contact bridge owners,
Draft report

How many bridges
How many on each roadway type
Why unknown: admin efforts needed?; tech effort needed?
Impact of UF

What is unknown? Material, structure, dimensions, other

Accessibility info for UFs

Literature search
Domestic & foreign
Transportation industry
Other industries—defense, mining/oil, telecom, other

What to review?
Mix of technologies and business practices related to
Soil, rock, water table characteristics,
Foundation types and geometrics
Foundation conditions
Costs of technologies/practices
Ease of use and reliability of tech/practices
Problems, advantages, disadvantages

Owner/Other Info
"Are you excited about UF issue" are you concerned about this or not
What is being done and why: technologies; experiences; who do work[contract out?];
How long will it take; how well is this working and how do you know?

If nothing be done, why not?
Outcomes of inaction? Is there a failure in the next year? Those outcomes?

Write the report
Format similar to NCHRP
Themes—where are we; where want to be; how to get there
Target audiences—bridge/geotech/hydraulic engineers; transportation execs

Preliminary findings/thinking
Technologies (NCHRP 21-05 + others—sonic echo

Lit Search
Are there hidden nuggets, ie a hidden state memo.
Looking at both easy to find and hard to find stuff.

Prelim findings—Biz practices
Risk based management
Decision tree analyses
Panel-based systems e.g. NCDOT
Knowledge based expert systems
Era-based soil-type/foundation assumptions. We do tend to build same way for same soil, Therefore similarities exist. If know eras of construction and what was done, then might know some facts about foundation. Every time state DOT digs up bridge need to check if info is correct. Need catalog findings and compare to existing data. Not just foundation but how do we know if info is good. If we start digging up foundations in poor state then that means others are in bad state. Also consider, cost of human life, need to determine this value or what it's worth.

Interesting Finding
Relatively "new" bridges continue to show up as UF in NBI
Record-keeping or record-transfer issue?—is it just an admin problem

Next project steps Get info from multi sources
Got info to share?—need to develop compendium of what info is out there.

Contact info Scott Sabol, PO Box 167, Randolph Center, VT 05061
802-728-1272; ssabol@vtc.edu

Audience knows a lot. My concern is for people not here, not as involved or proactive.


Q: Business practices. Sometimes need be required, maybe pilings nto really in ground. Need look at commonsense solutions. Always have deficiency in solutions
SS: Issue is using tool, right tool for right bridge.

Q: I'd like synthesis to include best current practices. Very important, extremely useful.
SS: I will do that. Will illustrate with case studies. Will include a bad practice too, illustration purposes.

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Updated: 06/27/2017
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