The clay deposits under the downtown core near Rosser Avenue behave very differently from the sandy glacial tills found in the Richmond Park subdivision. We see this contrast on nearly every project. A soil mechanics study in Brandon Manitoba must account for the high plasticity clays left by glacial Lake Agassiz. These clays shrink and swell with moisture changes. Meanwhile the tills on the city's east side provide more stable bearing conditions. Understanding this variability requires a thorough investigation that combines field sampling with laboratory testing. Before we drill we always review the local geological history because it directly affects foundation design. A proper classification of soils through Atterberg limits and grain size analysis helps us predict behavior under load.
The lacustrine clays of glacial Lake Agassiz control foundation behavior across most of Brandon. Ignoring their shrink-swell potential is the most common design error we correct.