When was the last time you have driven to Pennsylvania?
Did you cross a structurally deficient bridge at the time?
Structurally Deficient Bridges in Pennsylvania
If you have recently been to Pennsylvania, you must have crossed a bridge that may not really look like it’s nearly collapsing but is said to be deficient structurally. Those words sound scary and it’s not the only bridge in that condition.
Pennsylvania Needs To Replace 23% Of All The Bridges In The State
Pennsylvania happens to have over 30,000 bridges some of which span rivers while others are much smaller. There are some that cross highways and rural creeks. And out of these more than 30,000 bridges, over 6,000 are classified as structurally deficient.
What Structurally Deficient Bridges Refer To
Bridges that are structurally deficient are not unsafe, according to the project manager at the Intelligent Infrastructure Systems. Engineers use the term to classify specific bridges to highlight them for close monitoring, rehabilitation, repair, and in many cases, replacement. A lot of factors can be attributed to the bridge’s condition:
- Old age
- Lack of maintenance
- Traffic volume
- Materials used in construction
 Inspection Every Two Years
The bridges are inspected every two years. According to Intelligent Infrastructure Systems’ project manager, Ehsan Minaie, if an inspected bridge is found safe but requires repairs, engineers will give it a weight limit to prevent further deterioration. If the bridge is determined to be unsafe and is likely to threaten safety of the public using it, the bridge will be closed.
Rapid Bridge Replacement Project
For many years, the Pennsylvania Department of Transportation (PennDOT) engages companies to replace the bridges one or two at a time. With 23% of the state’s bridges classified as structurally deficient, PennDOT is trying to do something different. The department is hiring a team of private contractors who will be in charge of replacing hundreds of bridges owned and operated by the state under a program called Rapid Bridge Replacement Project.
From the structurally deficient bridges, many were found to be in need of replacement. But the process required in building a new bridge from obtaining permits, design and actual construction could take years. And for this reason, PennDOT is exerting all efforts to speed things up.
Under the program, the department expects replacement of about 558 bridges in 3½ years. If done through the traditional process, the state will need to wait a good 8 to 12 years to replace and build the bridges, according to Barry Schoch, Secretary of PennDOT.
Public-Private Partnership
The program is a public-private partnership (P3) and has a budget of $899 million. Pennsylvania passed the state’s public-private partnership law called Act 88 in 2012. Under the P3 program, the government partners with a private entity to design, build, maintain and in some cases, operate a public asset such as abridge or a highway. The Rapid Bridge Replacement Project (RBRP) is the first big project launched under said law.
The private entity engaged by PennDOT for the job is Plenary Walsh Keystone Partners, which is a partnership with several other firms including Plenary Group – the lead investor, HDR – the lead engineer and Walsh Group – the lead contractor.
Speeding Up The Process
All the bridges under the RBRP are around the same size and according to Ken Wright from HDR, engineers will be able to come up with a couple dozen standard designs which they can use repeatedly in various locations.
With standard design elements pulled from individual bridge sites, the engineers will be able to develop an overall design for a specific bridge and use it across all bridges. Additionally, the contractors will mass-produce some of the concrete parts of the bridge in an offsite factory prior to the start of construction. They could make a number of 50-foot concrete bridge surfaces. With factory-made components, the time needed to build bridges is tremendously shortened, thus expediting the process.
When you buy a bookshelf from the furniture maker Ikea, what you’ll get are pieces that have slotted ends. As you assemble the pieces together, you know which piece will fit into what slot. A similar process will take place when the contractor builds the bridge. A crane will lift the pieces up and slide them into place. Workers will join the pieces using appropriate structural bolts and nuts, and thru hardened steel flat washers to secure them. Assembling the factory-made pieces will take a shorter amount time than if constructed traditionally onsite. And with faster construction, the bridge will be closed to traffic for a much shorter duration.
Do you know what state-owned bridges are included in the RBRP project?
Article Sources:
http://crossroads.newsworks.org
http://radio.wpsu.org
