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DECEMBER 2017 \ BUILDING DIALOGUE \ 67
N ow that construction on the Regional
Transportation District’s Civic Center Sta-
tion is in its final stages, the more than
15,000 daily transit riders who use the sta-
tion will soon enjoy safer, easier and more transpar-
ent access to RTD services. For commuters or those
living, working or visiting downtown, the station’s
transition will help revitalize one of Denver’s most
iconic and visible public spaces with a thoughtful de-
sign that provides new form and improved function.
Three canopies outside the glass-enclosed station help
frame the views to and from Civic Center Plaza, high-
lighting its connection to Civic Center Park, the Capitol
and the 16th Street Mall transit corridor. The new center
will solve problems caused by aging infrastructure, and moisture leaks
that were plaguing the 30-plus-year-old former facility, along with traf-
fic routing for the buses. Civic Center Station serves 18 bus routes and
is bounded by 16th and Colfax avenues on the north and south, North
Broadway to the west and Lincoln Street to the east.
When complete, more than 160,000 craft labor hours will have gone
into this approximately $31 million project. Extensive management and
coordinationwere required to renovate a two-story station burrowed un-
der a landscaped plaza and situated above a single-level, 105,000-square-
foot underground parking garage, which was also connected to the adja-
cent 22-story Civic Center Plaza office building. The demolition required
to separate the station from the 4- to 6-inch-thick waffle slabs and 18- to
24-inch-thick beams that joined it to the Civic office tower was almost
like surgery. The year-and-a-half-long construction process continued
on schedule while accommodating the 5,000 people who use the office
tower during the week, in addition to RTD passengers who board buses
at nearby temporary shelters. Access to the tower’s loading dock, directly
adjacent to the station renovation, also had to be maintained, and vi-
bration from construction equipment had to be monitored to ensure it
stayed within limits.
Construction crews removed more than 12,000 cubic yards of concrete,
as well as 9,000 cubic yards of dirt, to bring the site down to the level of
adjacent street grades on the south and east borders of the project.
To support the concrete structure, the design called for a structural
fill solution based on the use of structural geofoam infill material, con-
sisting of closed-cell expanded polystyrene manufactured into large,
lightweight blocks. The team started out with nearly 220,000 cubic feet
of geofoam blocks to support the bus loading area, Lincoln level plaza
and terminal walkways, at depths varying from 18 to 60 inches. More
than 2,200 of these geofoam blocks were custom fabricated, based on la-
ser scans provided byMortenson’s virtual design and construction group.
Dave Espinosar
Senior Project
Manager,
Mortenson
Construc-
tion