3D DESIGN FOR MACHINE CONTROL GRADING A Case Study of ODOT's I-5: Willamette River Bridge Project...

3D DESIGN FOR 3D DESIGN FOR MACHINE CONTROL MACHINE CONTROL

GRADINGGRADINGA Case Study of ODOT's

I-5: Willamette River Bridge ProjectEugene/Springfield, Oregon

Tom Metcalf, PE– OBEC Consulting Engineers in Eugene,

Oregon– 13 years of roadway engineering

experience– Lead Roadway Engineer on the I-5:

Willamette River Bridge Project– Phone: 541-683-6090– Email: [email protected]

PRESENTATION BY:PRESENTATION BY:

CASE STUDY BACKGROUNDCASE STUDY BACKGROUND

ODOT I-5: Willamette River Bridge Project– $150M bridge replacement project in Eugene,

Oregon

Twin 1900-foot-

long I-5 Bridges

Twin 1900-foot-

long I-5 Bridges

2500 feet of I-5

Roadway Work

2500 feet of I-5

Roadway Work

2300 feet of I-5

Roadway and Ramp Reconstruc

tion

2300 feet of I-5

Roadway and Ramp Reconstruc

tion

How did machine control grading get incorporated into the I-5: Willamette River Bridge project?– Project is an alternative delivery project

where the prime contractor(Hamilton) participates in the design

– K&E Excavating requested machine control grading to be utilized because of cost savings

CASE STUDY BACKGROUNDCASE STUDY BACKGROUND

ODOT utilizes a 3D design software program called InRoads to model proposed surfaces– Past version of InRoads were not as powerful

What is 3D Design?What is 3D Design?

Note the

"tethered

modem"!

Initiating

Redesign!

Initiating

Redesign!

ODOT utilizes a 3D design software program called InRoads to model proposed surfaces– Past version of InRoads were not as powerful

What is 3D Design?What is 3D Design?

Old industry standard – Minimized design effort (save design time and design expenditures) by providing just enough design data for field staff to "fill in the gaps"New industry standard due to machine control grading – Increased design effort to eliminate all gaps in 3D design to minimize "field modifications" during construction

How Machine Control Grading How Machine Control Grading Changes 3D DesignChanges 3D Design

Used to do "close enough" 3D modeling–Why?

Remember – Past industry practice was to minimize design effort (save design time and design $$$) by providing just enough design data for field staff to "fill in the gaps"

– Examples?


BEWARE: TECHNICAL CONTENT AHEAD!!!!!!


Old = Large gaps between template dropsNew = Smaller gaps


• Modeling around bridges, abutments and wingwalls


Guardrail benches, sideslope transitions and structure section transitions


Some modeling was accidentally overlooked, such as drainage features


• Need experienced field staff to interpret design for "field fitting" gaps in the design

• Quantity overages since modeling is not accurately reflecting final field conditions

• Change orders for "filling in" the gaps in the design

Effects of Past 3D Design on Effects of Past 3D Design on Construction ProjectsConstruction Projects

• MORE RISK TO CONTRACTORS = MORE RISK BUILT INTO PROJECT BIDS = MORE EXPENSIVE PROJECTS FOR ODOT

• Greatly reduces field interpretation of design• More accurate quantities• LESS RISK TO CONTRACTORS = LESS

RISK BUILT INTO PROJECT BIDS = LESS EXPENSIVE PROJECTS FOR ODOT

• This is a proven concept. For a number of years, contractors have been requiring and paying for this level of modeling effort from designers on design-build projects.

Results of New 3D Modeling Results of New 3D Modeling PracticesPracticeson Construction Projectson Construction Projects

• Design $$$ < Construction $$$

• Must decide at the beginning of a project to do more detailed modeling– Difficult and time-consuming to upgrade

a design not tailored for machine control grading

• Introduces need for QA review of modeling– This results in substantially more design

time and design dollars

Impacts of New 3D DesignImpacts of New 3D Designon Engineering Effortson Engineering Efforts

• How does the 3D design get to the construction equipment?

• Contractors don't use InRoads….they all have different proprietary software

• Have to convert design models to Proprietary software models for machines to "read"

• Designer must QC proprietary software models before work begins

• Increases design time and design expenditures


Can utilize this concept for other design disciplines, such as traffic control plans

– Converting 2D traffic control plans to 3D staging design


• ODOT's current design software is InRoads XM, and it is more than capable of generating the 3D designs required for machine control grading. This is not a futuristic concept. It has been utilized on a number of past and current projects.

• 3D designs require more design time and design budget.

• Embrace change = Better product = Reduced construction cost to ODOT

CONCLUSIONCONCLUSION

Tom Metcalf, PE– OBEC Consulting Engineers – Phone: 541-683-6090– Email: [email protected]

QUESTIONSQUESTIONS

3D DESIGN FOR MACHINE CONTROL GRADING A Case Study of ODOT's I-5: Willamette River Bridge Project...

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