• Lehigh/Pohopoco Bridge Replacement Project

    Borton-Lawson

    Lehigh/Pohopoco Bridge Replacement

    Parryville, Pennsylvania, United States of America

Project Summary

Project
The original USD 101.5 million Pennsylvania bridge project called for replacing two twin bridges over the Lehigh River and Pohopoco Creek with four steel, long-span bridges. Given the dramatic increase in steel prices, Borton-Lawson was retained to design a conceptual concrete alternative. The new concrete project called for a complete structural redesign, new geotechnical program, and environment permit amendments. To accommodate these changes while maintaining the original project schedule, Borton required flexible, powerful, and interoperable bridge modeling software.

Solution
Borton-Lawson relied on Bentley’s InRoads and MicroStation to address complex bridge geometry, minimize construction materials, and meet design and construction deadlines. Using InRoads, Borton defined bridge elements and produced digital terrain models (DTM). The flexibility and interoperability of Bentley’s software enabled the team to accurately model bridge decks, quickly output data for every desired location, and incorporate the data output into customized Excel worksheets. Leveraging information modeling was key to consistency and significant in keeping the project on schedule.

Outcome
With accurate modeling information, Borton-Lawson improved production rates and delivered the final bridge design in less than eight months. The innovative use of Bentley software in conjunction with Microsoft Excel saved an estimated 410 hours, and enabled structural plans to be approved two months ahead of schedule. The early approval resulted in construction completion one year ahead of schedule, saving USD 7 million over the original design.

Software
The creative and flexible application of Bentley tools was instrumental in the redesign and timely construction of the bridge replacement. Using Bentley InRoads and MicroStation, Borton designed four state record-breaking concrete bridges, established optimal elevation of 175 pre-stressed girders, calculated precise 3D representation of 35 bridge spans, and output thousands of data points of critical bridge elements that served as the source data for custom Excel spreadsheets. The interoperability of Bentley software enabled Borton-Lawson to develop a powerful customized process, maximizing time and cost savings.

Outcome/Facts:
  • Borton-Lawson’s innovative application of Bentley solutions resulted in a USD 7 million construction savings and a completion date one year ahead of schedule.
  • Bentley software interoperability allowed Borton-Lawson to implement a customized design process that saved an estimated 410 hours.
  • Using MicroStation and InRoads, Borton-Lawson designed the pre-stressed concrete bridge concept in four weeks, finishing the final design in less than eight months.
Quote:
  • “The new bridges offer a safety enhancement over the previous structures because they feature wider shoulders to the left and right of the travel lanes. The shoulders provide the Turnpike motorists a buffer zone in case of an accident or breakdown – something the old bridges lacked.”

    Roger Nutt CEO Pennsylvania Turnpike Commission