CONSTRUCTION HANDOFF FOR MACHINE CONTROL GRADING. A Case Study of ODOT's I-5: Willamette River Bridge Project Eugene/Springfield, Oregon

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CONSTRUCTION

HANDOFF FOR MACHINE

CONTROL GRADING

A Case Study of ODOT's

I-5: Willamette River Bridge Project Eugene/Springfield, Oregon

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Tom Metcalf, PE

– OBEC Consulting Engineers in Lake Oswego,

Oregon

– 14 years of roadway engineering experience – Lead Roadway Engineer on the I-5: Willamette

River Bridge Project

PRESENTATION BY:

Phone: 503-620-6103

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- Agency staff?

- Consultants?

- Anyone attend the Aug 2010 – Machine Automation Conf in Eugene?

- Anyone attend the ODOT Region 1 Brownbag on Machine Control Grading?

- Rdwy designers?

- Rdwy designers that use InRoads XM?

- Anyone ever involved with Machine Control Grading on a project?

- Anyone involved in handing over Machine Control Design Data to Construction?

General Questions of the Audience

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1.

Case Study Background

2.

What is Machine Control

Grading

3.

What is 3D Design

4.

How Has Machine Control

Grading Changed 3D Design

5.

Case Study -

Handoff of

Machine Control Grading to

Construction

Presentation Outline

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CASE STUDY BACKGROUND

ODOT I-5: Willamette River Bridge Project in Eugene, Or.

– $150M bridge replacement project

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 Reconstruction 2300 feet of I-5 Roadway and Ramp Reconstruction

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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 BACKGROUND

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Contractor utilizes 3D design data rather than

field staking to construct project elements such as:

-

Rough grading of earthwork prism

-

Final grading of earthwork prism

-

Final grading of aggregate base

What is Machine Control Grading?

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Creates a Model of the Proposed Design Surface using Computer Software

- Takes 2D plans and converts it to 3D

- Used for establishing a project footprint - Generates earthwork and other

quantities

- Produces cross sections for construction staking

What is 3D Design?

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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?

ODOT now utilizes a newer

version of InRoads called XM – much more powerful and

capable of better handling 3D design

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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

Changes 3D Design

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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?

How Machine Control Grading

Changes 3D Design

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BEWARE: TECHNICAL CONTENT

AHEAD!!!!!!

Changes 3D Design

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Old = Large gaps between template drops

New = Smaller gaps

How Machine Control Grading

Changes 3D Design

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•

Modeling around bridges, abutments and

wingwalls

Changes 3D Design

REQUIRESBRIDGE, WALL CLOSE AND COLLABORATION ROADWAY WITH

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Guardrail benches, sideslope transitions and

structure section transitions

Changes 3D Design

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Some modeling was accidentally overlooked,

such as drainage features

Changes 3D Design

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•

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

Construction Projects

MORE RISK TO

CONTRACTORS

MORE EXPENSIVE

PROJECTS FOR ODOT

=

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• Greatly reduces field interpretation of design • More accurate quantities at bidding

• REDUCED RISK TO CONTRACTORS = 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 Practices

on Construction Projects

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•

Must decide at the beginning of a project to do

more detailed modeling

– Difficult and time-consuming to retrofit a completed

project not tailored for machine control grading

•

Introduces need for QA review of modeling

– Need to account for more design time and design

dollars due to added QA effort

Impacts of New 3D Design

on Engineering Efforts

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• How does the 3D design get to the construction

equipment?

Construction Handoff of Machine Control

Grading Information

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•

Handling/Converting of 3D Design Models

Grading Information

• 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

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• Earthwork Comparison between DTMs and Contractor Files

Construction Handoff of Machine Control

Grading Information

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•

DTM File Naming Convention

Grading Information

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•

DTM File Index

Construction Handoff of Machine Control

Grading Information

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•

DTM Index in Plan View

Grading Information

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•

Microstation File of All Alignments and

Edges of Pavement

Construction Handoff of Machine Control

Grading Information

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•

Annotated Cross Sections on 5’

Intervals

Grading Information

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•

Annotated Cross Sections for All

Non-Roadway Modeling

Construction Handoff of Machine Control

Grading Information

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•

Multiple Design Packages Required

Models Broken Up By Design Package

Grading Information

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Design Changes After Final PS&E

Require Remodeling During

Construction

•

Can be very time consuming

•

Requires full QC

•

Have to remodel quickly. Contractor

could claim delay.

•

Need to account for remodeling

effort in Construction Engineering

budget

Grading Information

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Per the Contractor’s request, Machine Control

Grading was utilized for other design

disciplines, such as traffic control plans

– Converted 2D traffic control plans to 3D staging

design

– Generated models by traffic control stage – Generated quantities by traffic control stage – Provided x-sections of each traffic control stage

Construction Handoff of Machine Control

Grading Information

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• 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.

• Embrace change = Better product = Reduced

construction cost to ODOT

• With Machine Control Grading, Construction

handoff is more involved and designer must be engaged throughout construction to

remodel as necessary

CONCLUSION

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Tom Metcalf, PE

OBEC Consulting

Engineers

503-620-6103

[email protected]

QUESTIONS