part ii – applications 3d engineered models for construction part ii - applications september 2012...

Part II – Applications 1

3D Engineered Models for Construction

Part II - Applications

September 2012


Review of Material from Part I

• Overview of 3D modeling • 3D plans, electronic data files, digital terrain

models• Benefits (to owner-agencies, contractors, and

A/E firms)• Use in field applications such as automated

machine guidance


The Focus of Part II

• Successes in implementation of 3D modeling• Specifications (what is used and how)• Project selection guidelines • Information sharing across entities• Common implementation challenges• Limitations to use of 3D modeling (practical examples)• Benefits and future uses (4D and 5D models)


History - BIM Applications for Building Construction

• Export 3D model to computer numerical control (CNC) machines

Photo courtesy of Autodesk


History - BIM Applications for Building Construction

• Allowed automation of structural shape cuts with a high level of precision

• Allowed development of an erection plan and sequencing for implementation



Where Application of 3D Modeling Started

Building Information Modeling• Unusual fabrications• Clashes between items

above ceiling tiles (HVAC, piping, etc.)

• Vertical construction Photo courtesy of Autodesk


BIM Influences on Transportation Applications

• Export 3D model to bridge girder fabricators for pre-fabrication

• Applies to highways in urban areas where utility networks might have clashes that need to be avoided


Further Application of 3D Models to Transportation Projects

• Models can support projects in all modes

• Example: model transit tunnel system



How 3D Modeling Can Fit Into Agency Programs

• 3D modeling can be used by itself or also linked to field applications such as automated machine guidance

• Designing in 3D helps practitioners visualize the project and identify potential design issues

• The future may see agencies transition to 3D design processes

• Accomplishing this transition is the first step (requires software, training, and experience)


Use of 3D Modeling with Enhanced Technologies

LIDAR – Light Detecting and Ranging (data intensive point clouds for 3D design)

Photo courtesy of ILDOT/MO State University


Uses of LIDAR for Point Cloud Data for 3D Model

• Get clearances for overhead, location of roadside appurtenances, etc.

• Nice if dealing with locations with clearance issues, etc.• If need an as-built for a bridge• May be used to evaluate earthwork quantities

Generates robust data for planning design and visualization


LIDAR Point Cloud for Overhead Structure



LIDAR Point Cloud for Roadway Segment



LIDAR and 3D Modeling

LIDAR Point Cloud

CAD/Design Data

Photos courtesy of Autodesk


Bridge LIDAR Video Example

• LIDAR point cloud 3D video visualization fly-by



Wisconsin DOT – US Hwy 10 Expansion

• Model based design allowed for faster, cheaper plan set development compared with traditional CAD design

Photo courtesy of Wisconsin DOT


Project Selection Guidelines

• Eventually all projects may be in 3D• Advantages – where a lot of stakeholder

input is expected• Projects with high probability of clashes• Where a considerable amount of earth

moving may be required (use of AMG)


Project Selection Guidelines (cont.)

• Where string lines are going to be problematic• Pavement projects where surface problem

corrections (severe undulation) require variable milling to improve the ride

What other project selection criteria have you used?


AMG Specifications

• Agencies may wish to avoid requiring the use of AMG, unless it is absolutely necessary for the success of the project (e.g. single lane white topping and pilot implementation projects).

• Do not want to limit potential bidders by specifying a method that only a few can use.


How Agencies Handle Specification Needs

• Often will not spec 3D modeling but allow contractors to use this innovative technique for greater efficiency and lower cost

• Some have a spec in case the contractor decides to use AMG

• The spec is only used if the contractor chooses to use AMG as part of the bid

• Encourages contractor to use AMG which would require a specification (QA requirements, how they will get the model, what they will do with it, waivers needed to get the model, etc.)


Communicating Information and Data

• 3D model is provided by agency• Contractor hires a company to process data

into machine file for use in the field• The contractor may handle 3D modeling using

their own personnel


Limitations to Use

• Model is a representation• Data intensive • Time limitation• Governmental agencies may be inundated

with requests for information in order to complete data prep on time


Changes in Surveying

• Augments an original survey that is performed• Grid survey as opposed to centerline survey


Transfer of Model from Designer to Constructor

• Contractors prefer– As detailed as possible– Before bidding

• Modifications will have to be made– Can a modified model be treated like a shop drawing?– What constitutes a design modification and therefore

requires a licensed professional and coordination with the original designer?

– What modifications merely add detail that carries out the original design intent?


AASHTO Resource for Application (TIG)

• Integration of 3D Modeling, GPS, and computer operated construction equipment


Opportunities and Challenges



Common Challenge

• Deciding how much detail to provide

Image courtesy of FHWA

Part II – Applications

Data

• Improve data management and exchange– XML and TransXML need to be more robust for

wide adoption– Standard procedures needed to pass files between

designer and constructor

28


Training

• Training and education needed for all– Stakeholders (owner, designer, constructor)– All levels• Designers and design technicians• Engineers and managers• Executives

29


Standardization• Standardize practices and processes agencies use

during modernization process.– Delivery of model to constructor– Project survey control– Techniques to survey for partial payment of quantities– Requirements for the 3D model – CADD standards,

design manuals, etc.

30


Benchmark Case Studies• Case studies demonstrate– Feasibility– Best practices

• Contracting authorities wish to see success in a context that is similar to their own

• May encourage adoption

31


Subgrades/Paving/Overlays

• Unique challenges that are different from earthwork applications– Greater accuracy required– Higher value materials– Perishable materials– Thickness and ride are more important than

elevation sometimes

32


The Future of 3D Modeling

• 4D models add schedule components

33


5D Model (Cash Flow)

34



• Application of 3D modeling for transportation can follow BIM applications used for buildings

• Models can provide cost savings, time savings, and clash detection for items such as utilities

• Technology applications such as LIDAR can provide robust data to supplement the 3D model

Summary


Questions?

Douglas Townes, FHWA-RC [email protected]

Richard McDaniel, [email protected]

Chris Schneider, FHWA-HQ202.493.0551 [email protected]

Bryan Cawley, FHWA-HQ202.366.1333 [email protected]

part ii – applications 3d engineered models for construction part ii - applications september 2012...

Documents