INVESCO FIELD AT MILE HIGH

Kumar & Associates, Inc. (K+A), performed geotechnical engineering, environmental studies, and conducted the construction  materials testing and observation for the design of Invesco Field at Mile High.  The stadium, which was constructed at the site of the old Mile High Stadium and McNichols Arena, consisted of a circular reinforced concrete and steel structure with an outside diameter of approximately 720 feet.  The structure has six main floor levels, with the lowest level floor matching the playing field elevation and the uppermost floor at an elevation approximately 200 feet above the playing field elevation. 

Straight shaft piers drilled into the bedrock were recommended as the preferred foundation type.  Additional services provided by K+A included geotechnical engineering report addenda to address site utilities, ring road pavement design, the pedestrian "Broncos Bridge" over the South Platte River and pavement design for Colfax/Federal interchange improvements; materials management and health and safety plans; and construction phase geotechnical engineering, materials testing, and environmental services. 

K+A provided Phase I Environmental Site Assessment (NEPA Hazardous Materials Study) services for the new stadium property.  The Phase I identified past usage of the property as a City and County of Denver landfill.  Based on that information, a Phase II Environmental Site Assessment was performed with the drilling of soil borings and installation of ground water monitoring wells.  Soil and ground-water sampling and monitoring indicated that there were no hazardous materials identified within the fill material or ground water.

During excavation of the landfill materials in the footprint of the stadium, K+A provided soil sampling of field monitoring and submitted samples for laboratory analysis to confirm that the soils removed were not hazardous or above state approved action levels for petroleum related compounds.  By evaluating geotechnical and environmental properties of the fills and careful coordination between geotechnical and environmental disciplines, 60-75% of the existing fill materials were allowed to be reused in areas outside the building, thereby saving hundreds of thousands of dollars on this net fill import project.

During the excavation dewatering for utility line construction, K+A provided weekly sampling of discharge to storm sewers in compliance with the project state NPDES permit.

Construction materials testing services provided during construction included observation of the installation of the drilled pier foundation system.  The drilled piers for this project provided several challenges such as the presence of ground water and lateral load concerns, which required careful monitoring to be sure that the surrounding supporting stratum was capable of resisting the lateral forces.  Other services provided included the observation and testing of the mass excavation and fill placement, post-tensioned slab system, reinforcing steel, structural concrete, structural masonry, fireproofing, site utilities, asphalt paving, and structural steel fabrication and erection.