RockSol Consulting Group, Inc.
  • Denver Union Station

    Denver Union Station

  • Denver Union Station

    Denver Union Station

  • Denver Union Station

    Denver Union Station

Denver Union Station Multi-Modal Transportation Facility


Client:

Denver Union Station Project Authority, consisting of representatives of City and County of Denver, Regional Transportation District, Denver Regional Council of Governments, DUS Metropolitan District, Colorado Department of Transportation

Services:

Structural & Geotechnical Engineering

Location:

Denver, Colorado

Project Description:

Between 2007 and 2011, RockSol provided services for the Denver Union Station (DUS) multi-modal transportation facility and redevelopment. RockSol services included basic preliminary geotechnical engineering for the Environmental Impact Statement, and structural and geotechnical engineering for the final design, as sub-consultant to AECOM, on the AECOM/Kiewit design-build contract. The DUS redevelopment is a 19-acre transit-oriented development project with retail locations, offices, and residential complexes. The development was accomplished under a public/private consortium with a budget of approximately $500 million. The redevelopment of DUS included a multi-modal transportation hub with integrated light rail, commuter rail, Amtrak intercity rail, regional bus, mall shuttle, downtown circulator, intercity buses, taxis, bicycles, and pedestrians. The DUS expansion project combines a below-grade bus terminal (bus box), at-grade and bridge crossings for commuter railroad lines, light rail transit, regional railroad lines, rail line platforms, retaining wall structures, new roadway and existing roadway improvements, and improvements to the existing DUS structure. The completed terminal includes three light rail tracks, eight commuter rail and heavy-rail tracks, platforms, underground bus terminals, waiting-room amenities, and shops and restaurants.


RockSol conducted the structural independent design check to assess structural components of the DUS terminal structure, divided among three structural plan packages. Structural components included prestressed concrete beams, deck, connections, substructure frames, pier caps, columns, and walls subjected to saturated soil lateral pressure. Superstructure calculations considered simple span behavior and continuous behavior for superimposed dead load and live load. AASHTO LRFD design code was used for Strength I and Strength II limit states, Service I limit state for concrete compression stresses, and Strength III limit state for prestressed concrete tension stresses. RockSol prepared summary documents of independent check results for each construction package and resolved issues with designers.


Additionally, RockSol performed numerous geotechnical investigations and recommendations for the final design, including pavement design and foundation recommendations for the underground bus terminal, platforms, rail lines, and the temporary Amtrak station. To characterize the subsurface soil conditions for the various DUS expansion facilities, RockSol drilled approximately 120 exploratory boreholes. Soil samples were collected at selected depths below the ground surface then examined by the project geotechnical engineer in the RockSol laboratory. Laboratory tests were performed on selected samples in general accordance with ASTM, AASHTO and current local practice. The geotechnical report presented the field and laboratory data and our conclusions and recommendations for design and construction of the proposed facilities, including foundation recommendations, retaining wall soil parameters, subsurface drainage considerations, seismic design considerations, street pavement thickness recommendations, excavation considerations, site grading, and fill placement specifications. RockSol was also responsible for measuring groundwater levels in several monitoring wells installed during the subsurface exploration for a three-year period.


The project has been recognized with numerous awards including the 2014 Neighborhood Transformation Award from the American Institute of Architects, the 2013 Gold Award from Spark Transport, and the 2013 Excellence in Structural Engineering in the New Buildings under $30 million from the Structural Engineers Association of New York, among others.