ARGET FIELD Station, located in downtown Minneapolis, is a state- deNt of-the-art, multimodal mass transit station in- iviC i ity i corporating complementary mixed-used devel- C s B opment and year-round public space. It is no ew Located in downtown Minneapolis, or disadvantage that it is also connected to Target N Target Field Station is more than simply a light-rail hub. N Field, the home of the Minnesota Twins. With A more than 500 trains passing through each day, In addition to facilitating the flow of large crowds to the home of the Target Field Station is the new “Grand Cen- tral Station” for Minneapolis, providing links Minnesota Twins, the station offers an amphitheater, public gathering spaces, to residential areas, workplaces, shopping and economic development opportunities. Designed with the environment in mind, destinations, major sporting events, and concerts while enabling travelers to visit other it also features innovative measures for collecting and reusing stormwater attractions in the Twin Cities area. runoff and snowmelt. ..... By Justin Gese, p.e., m.asce However, the facility is more than just a mass Ttransit station and mover of people. This mul- tiuse station is a community destination that provides a year-round public meeting space complete with expansive green lawns, lush veg- etation, and a 1,000-seat amphitheater. It offers new development opportunities for businesses and places for people to shop. Stormwater cap- tured on-site and water obtained through an in- novative snowmelt system are conveyed to an adjacent energy facility and reused. Moreover, the station features sustainable landscaping, and the various other context-sensitive design and construction techniques employed give it a light environmental footprint. On a fundamental level Target Field Station was designed to accommodate the significant number of riders who use the rail network in Minneapolis to attend Twins games, outdoor music concerts, and other events at Target Field. For example, more than 8,000 people descend upon the station’s platforms to board a light- rail train or a Northstar Commuter Rail train after a Twins game. Against this backdrop, the station had to be able to handle large numbers of passengers rapidly and efficiently. It had to offer the right amount of space with a suitable layout and adequate signs to help passengers orient themselves and find their trains quickly, easily, and safely. For its part, the design of the station achieved all these objectives while ac- complishing much more. The design of Target Field Station took in- spiration from Minnesota’s distinct seasons and The station’s upper-level plaza includes an area called the its residents’ love of the outdoors. The project’s Light Garden, which features nine programmable light-emitting common areas were specially laid out to support diode fixtures interspersed among the plaza’s tree trenches, a variety of activities both for users of mass tran- along with the Great Lawn, a green expanse complete with a sit and for others. The project team incorporat- 15 by 30 ft video screen located on top of the elevator bank. ed an “open transit” station plan that focuses on © MORGAN SHEFF/COURTESY OF PERKINS EASTMAN © MORGAN SHEFF/COURTESY creating distinctive urban spaces. Target Field [68] Civil Engineering n o v e m b e r 2015 n o v e m b e r 2015 Civil Engineering [69] Copyright © 2015 American Society of Civil Engineers. All rights reserved. THE CHALLENGES AssoCiAted with the site led to the use of A uNique trilevel desigN. construction of various temporary access lanes to maintain HERC operations. Because of poor soils at the site, all of the project structures had to be built on steel pipe piles and H-piles. Posttensioned concrete was used because of its strength and constructability. The design, however, also called for concrete curves, cascades, and stairs, complicating the construction process. The challenges associated with the site led to the use of a unique trilevel design. The third, or uppermost, level in- cludes the light-rail station, which is located under a light- ed canopy and serves the METRO Blue and Green lines. The massive 300 ft long canopy stands 25 ft above the platforms, and its fins comprise a total of 2,400 pieces of aluminum. The canopy features programmable light-emitting diodes that can change to any color, creating a must-see attraction. The plaza on this level includes an area called the Light Garden, which features nine fixtures with programmable light-emitting diodes interspersed among its tree trenches. The plaza also invites people to enjoy the Great Lawn, a large green expanse complete with a 15 by 30 ft video screen lo- cated on top of the elevator bank. The screen is used for game day broadcasts as well as for other events hosted by Henne- pin County, Target Corporation, or the Minnesota Twins. Yet another feature of the plaza is the light-rail bridge, which comprises 13 precast-concrete spans ranging in length Station embodies the five primary design principles of open North. To create additional parcels for development, the The train platform is covered by a 300 ft long, 25 ft tall transit in that it incorporates all modes of transit; promotes project realigned and added a signalized intersection at both canopy whose fins comprise 2,400 pieces of aluminum, development; creates iconic indoor and outdoor spaces; ap- 6th Avenue North and 6th Street North. opposite. Two large cisterns, right, can store 40,000 gal peals to passengers, residents, office workers, and visitors alike; Meeting all of the project design needs required using ev- of rainwater and snowmelt from the upper-level plaza and integrates culture with mass transit by placing the latter ery square inch of the compact 8-acre site, which is owned by and the bridge. Stored temporarily in the cisterns, the in the heart of the public square. Incorporating these design Hennepin County and includes the HERC. When completed, water is pumped to the nearby Hennepin Energy Recovery principles resulted in a project that offers significant benefits the Target Field Station project site encompassed approxi- Center, which reuses it in various industrial processes. to those attending games, as well as to the surrounding com- mately 58 percent of the total parcel. The HERC occupies the munity, visitors, mass transit users, and the environment. remaining 42 percent. completed in April 2014, and the station opened to The 104,000 sq ft station is situated in a highly urban- Scheduling pressures prompted the project owner, Hen- the public the following month. ized site that once included government administration nepin County, to realize the project through the design/build In addition to dealing with a pronounced lack of buildings and still contains the Hennepin Energy Recov- approach. In fact, the eventual design/build team would have space, the project team, as part of its construction ery Center (HERC), a waste-to-energy facility that burns only 24 months to complete the project after winning the planning and logistics efforts, had to remove con- 365,000 tons of waste a year to generate electricity. Besides contract in June 2012. This accelerated schedule was dictat- taminated soil from areas in which excavation per- the station itself, the site had to offer pedestrian plazas, ele- ed by the need for the station to be constructed by the time taining to foundation construction and piling instal- vated light-rail tracks and a supporting bridge, a 286-space the light-rail route known as the METRO Green Line became lation was planned and to demarcate utilities that parking structure, room for retail businesses, and a system operational, in May 2014. Another important consideration would be either abandoned or relocated. Construc- for managing stormwater. was that Major League Baseball’s 2014 All-Star Game would tion phasing also was essential given the critical op- The project team also factored into the site design the be played at Target Field on July 15. erations of the HERC. That facility generates enough need to facilitate future economic development. To this end The Minneapolis office of Knutson Construction led the steam energy to provide electricity to 25,000 homes, the site design involved the realignment of nearby roadways design/build team, which included the Minnetonka, Minne- as well as to power heating and cooling systems in to offer the flexibility that would attract and be conducive to sota, office of Short Elliott Hendrickson, Inc. (SEH). The lat- nearby buildings. Therefore, the project team had to development. In fact, the project’s preliminary design was ter provided design services pertaining to civil engineering, ensure that the 200 garbage trucks that visit HERC modified to improve the development potential of two road- landscape architecture, geotechnical engineering, and storm- each day would continue to have access during con- SEH ways adjacent to the site: 6th Avenue North and 5th Street water management. Begun in July 2012, construction was OF PERKINS EASTMAN © MORGAN SHEFF/COURTESY struction. This required a detailed phasing plan and [70] Civil Engineering n o v e m b e r 2015 0885-7024/15-0011-0068/$30.00 PER ARTICLE n o v e m b e r 2015 Civil Engineering [71] THE PROJECT TEAM opted to use lArge geofoAm BloCks As A lightweight Alternative, iN some AreAs stackiNg them to A height of 15 to 20 ft. from 40 ft to 90 ft. Approximately 1,050 ft long, the bridge here takes Northstar Commuter Rail passengers to the north- supports the rail lines, the station terminal, and the platforms ern suburb of Big Lake, nearly 45 mi outside of Minneapolis. for the METRO Blue and Green lines.