ST CLAIR COUNTY, ILLINOIS The services of Gonzalez were procured by Crawford, Murphy, & Tilly, Inc. (CMT) to provide geotechnical investigation and design recommendations for proposed terminal improvements at MidAmerica St. Louis Airport (MAA) in St. Clair County, Illinois. The modifications were made necessary due to significant growth at the airport over the past several years, increasing in annual passenger enplanements from 13,542 in 2013 to 123,841 by the end of 2017. Improvements proposed for the project include expansion of the existing 2-story terminal facility, passenger curbside modifications, terminal apron fillet widening, and entry/exit roadway reconfiguration.
Gonzalez reviewed extensive historical geotechnical data and used this information to develop a targeted geotechnical investigation. Gonzalez conducted a subsurface investigation that included 9 soil borings at the locations of proposed MAA improvements. Borings were taken at a range of 10—40 feet in depth using hollowstem auger drilling methods. Gonzalez performed laboratory tests on selected soil samples, including visual classification, water content, Atterberg limits, grain-size analysis, unconsolidated-undrained triaxial tests, and consolidation tests.
Upon completion of the subsurface investigation, Gonzalez prepared the project’s geotechnical report. Based on the proposed improvements to MAA facilities and composition of the soil at the project site, shallow foundation and below-grade wall geotechnical design recommendations were provided.
