The Grand Rapids Medical Corridor North Pedestrian Tunnel is a tunnel

Subway (underpass)

In England and Wales, the Republic of Ireland, Hong Kong and some Commonwealth countries , the term subway normally refers to a specially constructed underpass for pedestrians and/or cyclists beneath a road or railway, allowing them to reach the other side in safety.The term is also used in the...

 in Grand Rapids, Michigan

Grand Rapids, Michigan

Grand Rapids is a city in the U.S. state of Michigan. The city is located on the Grand River about 40 miles east of Lake Michigan. As of the 2010 census, the city population was 188,040. In 2010, the Grand Rapids metropolitan area had a population of 774,160 and a combined statistical area, Grand...

 connecting the Lemmen Holton Oncology Center with Butterworth Hospital

Butterworth Hospital

Butterworth Hospital is a hospital in Grand Rapids, Michigan. Founded in 1875 as St. Mark's Home and Hospital, the current Butterworth Hospital is a subsidiary of Spectrum Health. The hospital is a teaching affiliate of the Michigan State University College of Human Medicine. The emergency...

 and Helen DeVos Children's Hospital

Helen DeVos Children's Hospital

Helen DeVos Children's Hospital is a pediatric hospital in Grand Rapids, Michigan and a division of Spectrum Health. It is named for Helen DeVos, wife of Amway founder Richard DeVos, a major donor.-Awards and recognition:...

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Construction

The tunnel passes under Michigan Street, a busy thoroughfare. Construction was accomplished using the New Austrian Tunneling method without disrupting the traffic moving on the street above. The tunnel was mined through glacial till, which was grout

Grout

Grout is a construction material used to embed rebars in masonry walls, connect sections of pre-cast concrete, fill voids, and seal joints . Grout is generally composed of a mixture of water, cement, sand, often color tint, and sometimes fine gravel...

ed with Sodium silicate

Sodium silicate

Sodium silicate is the common name for a compound sodium metasilicate, Na2SiO3, also known as water glass or liquid glass. It is available in aqueous solution and in solid form and is used in cements, passive fire protection, refractories, textile and lumber processing, and automobiles...

 to stabilize it prior to digging the tunnel. The tunnel is lined with 15 inches (380 mm) of shotcrete

Shotcrete

Shotcrete is concrete conveyed through a hose and pneumatically projected at high velocity onto a surface, as a construction technique....

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In 2007, it received the ABC/WMC Construction Award from the Associated Builders and Contractors–Western Michigan Chapter.