Accessing the Mall of America
The 4,200,000-sq. ft. Mall of America is a colossus attracting millions to the Bloomington, Minnesota area.
Access to this retail-entertainment megaplex challenged the Minnesota DOT to develop a fast track solution to modify and add interchanges to three major arteries adjacent to the site, and all the while maintain traffic flow. A test pile program was conducted to determine the most economically feasible foundation in an area noted for its challenging soil conditions. Minnesota DOT utilized the pre-bid test data to bid the piling on a per-pile basis and eliminated the common practice of bidding per foot which requires contingencies to be built into the contractor’s price.
The uniformly-tapered Monotube® pile provided 150-ton ultimate capacity in the 42- to 47-foot range compared to straight-sided pipe which had previously been driven from 100 ft. to 130 ft. depths in the immediate area. The test program also benefited both the construction schedule and costs by providing very accurate Monotube® pile bid length estimates throughout the extensive construction area involved.
Over 2,700 Monotube® piles were driven in three separate multi-million dollar highway contracts which included 12 bridges and several tunnels. Distribution of the load throughout the bearing strata by the wedging action of the Monotube® uniform taper resulted in more consistent tip elevations and higher capacities. What’s best, MNDOT realized enormous savings by using Monotube® piles, a pre-design test program and their bidding technique.