Scarborough, ME: In-Situ Soil Mixing, Lowes - Retaining Wall Sub-Grade Improvement
Geo-Con installed soil-cement columns using in-situ shallow soil mixing. The purpose of the soil mix columns was to improve the shear strength of the soil under a future retaining wall. The project was part of the construction of a new Super Wal-Mart.
Geo-Con offered a value engineering solution on this project. The design originally called for 24-inch diameter stone columns to be installed. Geo-Con's proposed alternate for 36-inch soil-cement columns was accepted by the engineer. A pattern of 3 rows of columns, spaced 8 feet apart, was selected. A total of 246 columns were installed to an average of 30 feet deep. The columns were drilled through sand and clay layers to bear on the glacial till layer.
Minimum unconfined compressive strength of 60 psi was specified by the engineer. Geo-Con achieved a range of 96 to 278 psi in samples collected during production, with an average of 194 psi.