MoDOT’s Improve I-70 program is a statewide effort to reconstruct and expand nearly 200 miles of Interstate 70 between Blue Springs and Wentzville. The program is being delivered through multiple major contracts, with a primary goal of providing three lanes in each direction while modernizing the corridor’s pavement, bridges, and interchanges.
Parrish Structural Reinforcements serves as the MSE wall design engineer for Elevate Infrastructure on multiple Improve I-70 design-build segments. Across the four segments currently awarded to Elevate and PSR, our work includes approximately 223,000 square feet of permanent MSE panel walls across 68 structures, along with temporary wire-faced MSE walls.
A Program-Scale MSE Design Effort
Across the Improve I-70 program, PSR has addressed a wide range of project-specific geometry, geotechnical conditions, structural interfaces, and design criteria.
PSR’s scope includes engineering for permanent precast-panel MSE walls and temporary wire-faced MSE walls, including several conditions where conventional MSE geometry is not possible.
Limestone bedrock occurs within portions of the proposed reinforced soil zones. Where excavation into competent rock would otherwise be required to accommodate conventional reinforcement lengths, PSR has developed stable-feature MSE (SMSE) designs to address the restricted reinforcement geometry.
Other walls include acute corners and complex alignments requiring the MSE reinforcement layout and facing geometry to be developed around nonstandard conditions.
Portions of the program are also subject to seismic design requirements that required variable reinforcement lengths within the MSE walls to satisfy the applicable seismic criteria.
Subsurface conditions have introduced another layer of complexity. Shale pockets encountered within portions of the corridor required evaluation of the proposed MSE configuration in coordination with the project geotechnical engineer so that the wall design appropriately reflected the anticipated foundation and excavation conditions.
PSR continues to pursue additional Improve I-70 segments as the remaining corridor contracts are awarded.
