Queue length: 0

Note: Maximum image size is 5 MB

Please make sure you have permission to upload the photo. Only images you own, are explicitly labeled as "public domain" or have a CCO licence may be uploaded. Please complete all the fields to the right.

Drop files here

Photo License

You must select a photo license. For more information on licenses see:

CC BY-SA 4.0
CC BY-SA 3.0
CC BY-SA 2.5
CC BY-SA 2.0
CC BY 4.0
CC BY 3.0
CC BY 2.5
CC BY 2.0
FeaturedImageStatusPhoto License

Weight-Restricted Bridge Crossings Investigation

Complete

Chesterfield, Virginia, United States

Page owner: JMT (Johnson Mirmiran & Thompson, Inc.)


Project Overview
Project Name: Weight-Restricted Bridge Crossings Investigation
Date Completed: 2017
Location: Chesterfield, Virginia, United States
Project Status: Complete
Project Type: TransportationBuilding/Structural

Project Tags: bridge testing structural transportation innovative


Project Team

Disciplines That Worked on Project

Civil Engineer: Structural (Bridges)Civil Engineer: Transportation (Bridges)

Project Details
About this project
Fortunately, this day in age we have access to cutting edge, life-saving technology and equipment. However, those two items are highly dependent on monetary resources and access. Here in the United States, we are blessed with both of these items in relative abundance compared with the rest of the world. However, with an aging infrastructure, access to this type of care can quickly be impacted by weight restricted bridges. For example, throughout Chesterfield County, emergency response vehicles were unable to use specific routes when responding to emergencies due to weight restricted bridges. The weight restrictions varied per bridge but typically wouldn’t allow anything larger than an ambulance to cross the bridge. The large geographic size of the County along with steady growth prevented the County from providing timely responses to emergencies. Unfortunately, this problem is prevalent throughout the Commonwealth of Virginia and the nation. Therefore, Chesterfield Department of Transportation retained JMT to assist with evaluating weight restricted bridges in the County and ultimately load testing each bridge so that all emergency response vehicles could pass existing bridges.
Who benefits from this project, and how?
At the completion of the load tests and processing of the test data, JMT submitted a Crossing Authorization for each bridge and subsequently secured a Land Use Permit for emergency response vehicles to cross the bridges. For the first bridge to obtain a Land Use Permit, the emergency response time was reduced by 90 seconds for 16 residential parcels and $6.5 M of property. All of Chesterfield County will benefit from faster response times, because emergency response vehicles will no longer have to take alternate routes to avoid weight-restricted bridges.
What's unique about this project?
During project development, it was determined that the weight restrictions for each bridge were controlled by the fact that there were no plans for the existing abutments. Therefore, JMT could analyze the existing superstructure but that would have no impact on the weight restriction. After coordinating with Virginia Department of Transportation, it was determined that changes to the weight restrictions could only be made after additional investigation of the abutments was performed to evaluate overall stability. At that time, it was determined that the best way to remove the weight restrictions was to perform a load test on the bridge abutments. Live load testing of existing superstructures is relatively common. However, no live load testing of existing substructure elements had been performed by FHWA, States, or consultants.

Therefore, JMT developed load test criteria and test procedures from scratch and coordinated with the Virginia Department of Transportation, the Virginia Department of Motor Vehicles, and the Virginia Transportation Research Council (VTRC) throughout the process. Test criteria included three test locations at each abutment. Abutment rotation was monitored by tiltmeters while displacement was monitored by conventional survey and laser scanning of pre-determined survey markers. The test vehicles included the heaviest emergency response vehicle that could be supported by the bridge superstructure.

Funding & Costs
Funding source: Public
Funding notes: In general, Chesterfield Department of Transportation (CDOT) invested approximately $10,000 to analyze seven bridge superstructures within the county. Out of the seven bridges, three bridges were eligible for load tests, which cost approximately $30,000 per bridge to conduct the test, process the data, and submit the Crossing Authorization.



More Projects

Congratulations! Your project is ready to publish.
Thank you for helping to keep this site positive.
Congratulations! This project page now belongs to you.