St. Louis Arch Grounds – City+Arch+River
Client/Owner: National Park Services CityArchRiver 2015 Foundation
Location: St. Louis, Missouri
Services: Drilling, Geotechnical, Special Inspections
In fall 2010, Michael Van Valkenburgh & Associates (MVVA) won The City+The Arch+The River 2015 International Design Competition to develop a new concept for the Jefferson National Expansion Memorial (JNEM) commonly known as the St. Louis Gateway Arch Grounds. Elements of the new design for the grounds include expanding the Arch Museum and adding a major new entry facing Memorial Drive; creating a beer garden/restaurant that converts to an ice skating rink in the center; an urban ecology center; a wetland/bird sanctuary, a cobblestone walkway and three new parking garages. Final design and construction is to commence by 2015, the 50th anniversary of the completion of the Gateway Arch.
In 2012, Geotechnology provided subsurface exploration and engineering recommendations for the Park Over the Highway portion of the project which includes the landscaped bridge and replacement bridge over the depressed section of I-70. In coordination with MoDOT and the City of St. Louis special traffic control procedures were used and drilling was performed at night when there was less commuter traffic. Difficulties during drilling included working around the Cardinal’s Post-season games, numerous utilities rubble fill and varying rock quality. In addition, Memorial Drive was required to be open by 5:00 a.m. each morning. The structure was designed with minimal impact to the existing retaining walls (i.e. foundations were installed behind the walls). Special hybrid drilled shafts were also designed to expedite construction and reduce vibrations on neighboring structures (predominately the Old Cathedral).
Geotechnology provided a Phase I Environmental Site Assessment, a geotechnical desk study, and an archaeological desk study. The purpose of these services was to identify potential ground hazards and corresponding primary risks at an early stage so that these risks could be better managed during the design and construction processes. The geotechnical report addressed deep foundation excavation and shoring considerations, impacts of soil types, obstructions and environmentally impacted material on site grading, structural foundations considerations, and groundwater related considerations. The purpose of the Phase I ESA is to provide a professional opinion as to the potential for Recognized Environmental Conditions (RECs) to exist on the site, particularly hazardous substances or petroleum products on the property or that may have been released onto the property, the subsurface or surface waters in the past.
Geotechnology also provided utility locating services and detailed geotechnical exploration for the new visitors center, regraded slope over TRRA rail tunnel down to the Leonore K. Sullivan Boulevard, and new Rangers Station. Geotechnology provided specialist sampling and analysis services for soils nutrient assessment.