Twin Ports Interchange - Minnesota's Largest Ground Improvement Project-PPT Presentation

PPT Presentation

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The Twin Ports Interchange project in Minnesota replaced aging, low-profile bridges—costly to inspect and maintain and poorly suited to heavy port freight—with earth embankments and upgraded interchange infrastructure. Delivered through a construction-manager/general-contractor (CMGC) approach, it became Minnesota’s largest ground-improvement project.<br /><br />The column-supported embankment system covered about 67,063 square yards (13.8 acres) and included 8,046 ground-improvement elements: 6,750 concrete columns and 1,836 steel H-piles. The work cost approximately $23.7 million, including columns, caps, a load-transfer platform, lateral reinforcement, and testing. The wider interchange includes seven bridges, ten retaining walls, new drainage, lighting, signs, and concrete pavement.<br /><br />Subsurface conditions varied substantially, with shallow and deep compressible soils, intermittent sand layers, glacial till, and bedrock. Three-dimensional numerical modeling using a Plastic Hardening soil model informed the design of the embankments, abutments, walls, columns, piles, and lateral reinforcement. Modeling indicated that #10 reinforcement bars in a lower layer approached yielding; using #14 bars addressed the concern and helped control lateral spreading.<br /><br />Construction included concrete columns and caps, H-piles, steel plates, a load-transfer platform, and lateral reinforcing bars. Instrumentation monitored pore pressure, settlement, axial strain, lateral strain, and lateral displacement to assess ground and structural performance.

Keywords

Twin Ports Interchange

Minnesota

ground improvement

construction-manager/general-contractor

CMGC

column-supported embankment

concrete columns

H-piles

3D numerical modeling

lateral reinforcement