Influence of the Accuracy of a Bridge Weigh-In-Motion System on the Determination of a Bridge Assess...
Download
1 / 21

Jason Dowling Arturo González Eugene O’Brien - PowerPoint PPT Presentation


  • 115 Views
  • Uploaded on

Influence of the Accuracy of a Bridge Weigh-In-Motion System on the Determination of a Bridge Assessment Dynamic Ratio. Jason Dowling Arturo González Eugene O’Brien. Quick Overview. - Bridge Weigh-In-Motion Model Description Assessment Dynamic Ratio Bridge Weigh-In-Motion Accuracy.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Jason Dowling Arturo González Eugene O’Brien' - badru


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Influence of the Accuracy of a Bridge Weigh-In-Motion System on the Determination of a Bridge Assessment Dynamic Ratio

Jason Dowling

Arturo González

Eugene O’Brien


Quick Overview on the Determination of a Bridge Assessment Dynamic Ratio

  • - Bridge Weigh-In-Motion

  • Model Description

  • Assessment Dynamic Ratio

  • Bridge Weigh-In-Motion Accuracy


Bridge Weigh-In-Motion on the Determination of a Bridge Assessment Dynamic Ratio

Bridge Weigh-In-Motion systems use instrumented bridges to collect data on the truck fleet at a specific location.

  • - This concept was first proposed by Moses (1979)

  • Strain transducers are attached to the soffit of a bridge

  • Axle detectors are placed on the road surface

  • An algorithm is used to interpret the data

source: WAVE (2001)


Bridge Weigh-In-Motion on the Determination of a Bridge Assessment Dynamic Ratio

  • Moses Algorithm (1979) remains the most popular algorithm used in Bridge Weigh-In-Motion systems.

  • - Based on minimizing the sum of squares of differences between theory and measurements:

Lots of measurements are available during the truck crossing...

- This is utilised to smooth out the dynamic component.


Bridge Weigh-In-Motion on the Determination of a Bridge Assessment Dynamic Ratio

Typical ‘Measured’ Response


Bridge Weigh-In-Motion on the Determination of a Bridge Assessment Dynamic Ratio

Theoretical Response

x


Bridge Weigh-In-Motion on the Determination of a Bridge Assessment Dynamic Ratio

Matrix Solution Technique

Minimizing the Error function,

gives a system of simultaneous equations in Wi

Where {W} is a vector of the desired axle weights


Model Description on the Determination of a Bridge Assessment Dynamic Ratio

Truck Model

- 8 Degrees of Freedom


Model Description on the Determination of a Bridge Assessment Dynamic Ratio

Data Used for simulations of truck crossings...

Statistical Data for - GVW & Velocity

- Axle Spacing

- Axle Weights


Model Description on the Determination of a Bridge Assessment Dynamic Ratio

Data Used for simulations of truck crossings...

Carpet Profile


Model Description on the Determination of a Bridge Assessment Dynamic Ratio

Model Accuracy Classification

COST323 (2002) proposed a method of classification for Bridge Weigh-In-Motion systems

- The models classification under this method is ‘B+(7)’

  • Most individual axle weights predicted within ± 7%

  • Axle group weights & GVW predicted within ± 5%


Assessment Dynamic Ratio on the Determination of a Bridge Assessment Dynamic Ratio

Assessment Dynamic Ratio (ADR) is defined as:

i.e. Not necessarily associated with a single loading event

Recent work has discovered a tendency for ADR to decrease as Return Period, or Load Effect increases.


Assessment Dynamic Ratio on the Determination of a Bridge Assessment Dynamic Ratio

Trends in ADR with Time...

source: Rattigan (2007)


Assessment Dynamic Ratio on the Determination of a Bridge Assessment Dynamic Ratio

Trends in ADR with Time...

source: SAMARIS (2006)


Assessment Dynamic Ratio on the Determination of a Bridge Assessment Dynamic Ratio

Trends in ADR with Time...


Bridge Weigh-In-Motion Accuracy on the Determination of a Bridge Assessment Dynamic Ratio

Inferred Static Response


Bridge Weigh-In-Motion Accuracy on the Determination of a Bridge Assessment Dynamic Ratio

Inferred Static Response


Bridge Weigh-In-Motion Accuracy on the Determination of a Bridge Assessment Dynamic Ratio

Inferred Static Response

Error in Maximum Static


Bridge Weigh-In-Motion Accuracy on the Determination of a Bridge Assessment Dynamic Ratio

Error in prediction of ADR


In Summary: on the Determination of a Bridge Assessment Dynamic Ratio

Moses Algorithm tends to over estimate the maximum static response.

This leads to an underestimation of ADR

Future work will look at further understanding this inaccuracy

With a view to quantifying this or suggesting possible remediation measures...


My Thanks to the 6th European Framework Project ARCHES (Assessment and Rehabilitation of Central European Highway Structures) for funding my work.

Thank you for listening.


ad