Bridges: Representative Special Bridge Related Projects/Research Projects

DOR Single and Multiple Span Inverted Tee (IT) Standards Development
Developed single and multi-span Inverted Tee (IT) bridge superstructure system standards for the State of Nebraska.  These standards are similar to the current cast-in-place slab standards and are being developed to help counties, cities, and states to efficiently and cost effectively design and construct precast shallow bridges.

US Army Corps of Engineers’ Rapid Over-bridge Standard Design
The purpose of the project was to develop a rapidly constructed concrete over-bridge system that replaces a damaged bridge span in a period not exceeding 12 hours. This project involved the design and detailing of a concrete bridge alternate to the existing Mabey or Bailey bridge systems which are both steel truss type bridges.  The COE has experienced shortages in supply of the Mabey and Bailey products and thus needed a concrete alternate to these steel bridge options.

The developed precast beams and ramps system are set on the damaged span over the existing superstructure and piers (or abutments).  The proposed beams can be rapidly installed and assembled through transverse post-tensioning at the precast diaphragms. The novel curved top surface allows for considerable reduction of the length of the ramp generally required for the steel bridges with prismatic section. The bridge system is demonstrated for a 21.3 m (70 ft) span under heavy military loads. Each piece is limited in weight to about 12.7 metric tons (14 tons) and in depth to 0.9 m (3 feet). The on-site construction operation is minimized as no cast-in-place concrete or grout is required. As a removable bridge, the precast beams and ramps can be easily disassembled and reused. Despite the relatively complex precast component shapes, the cost of the formwork can be amortized over an extensive amount of production. This project focused on a simple-span replacement for any bridge width in increments of 0.6 m (2 ft). Although the system was designed for military applications as a substitute for prefabricated steel bridges, it has great potential for civilian applications.

National Cooperative Highway Research Program (NCHRP)
Project in conjunction with The George Washington University on full-depth, precast-concrete bridge deck panel systems

Federal Highway Administration (FHWA)
Project “Compilation and Evaluation of Results from High Performance Concrete Bridge Projects”

Precast/Prestressed Concrete Institute (PCI)
Project(s) to “Update and Incorporate the Current AASHTO LRFD and Standard Code Changes” into the PCI Bridge Design Manual.

FHWA Generic Workshop HPC Bridge Design Module
InfraStructure was retained as a member of a group of consultants, sponsored by the Federal Highway Administration’s Office of Technology Applications, to develop seminar materials to guide bridge designers in the use of HPC.

Development and Validation Support for LEAP Software - LEAP Software is a bridge industry leader in the development of bridge engineering software.  It is a highly visible company known to provide particularly reliable engineering software products.  Over thirty State Departments of Transportation, the Federal Highway Administration, numerous local governmental entities, and most ENR top 500 consulting firms currently use LEAP’s software.

As a result of its special knowledge and skill in the area of precast/prestressed concrete bridge design, IS was retained by LEAP to support the continuing development and validation efforts associated with its specialized bridge design software.  Over the past couple of years, TA has provided technical support on the following software programs:

  • Conspan – Used for Continuous Precast/Prestressed Girder Bridge Design
  • Consplice – Used for Specialized Spliced/Post-tensioned Bridge Design
  • RC-Pier – Used for Bridge Substructure Design

Graduate Thesis – Implementation of the Inverted Tee Bridge System
Prepared a laboratory testing program to develop new methods of creating continuity for the IT bridge system prior to casting the slab.  Used computer modeling to develop new live-load distribution factors for the system and instrumented the Little Papillion Creek bridge in Omaha NE to confirm the expected results.  Developed various design aids to be used with the new system