Several structures on the Southern Colorado State University Campus northeast of Pueblo have been damaged because swelling soils were not recognized or compensated for adequately in design, construction and maintenance of buildings, sidewalks, driveways, and water lines. Water percolating into dry soils exposed by construction excavation caused the clays to expand, exerting tremendous upward pressures. Floors, walls, ceilings, sidewalks, water lines, driveways, and other improvements have sustained an estimated $1.5 million in damages.
In 1976 at the site of the new maximum security facility for the Colorado State Prison in Fremont County, swelling soils and bedrock were shown on geologic maps. Field investigations and soils tests resulted in a remedial plan by the geologic and soils engineers, architect, builder and others on foundation design, drainage and landscaping. Millions of dollars in potential damages were avoided.
Image on right. Surface view of a near-vertical bentonite layer in the Upper Cretaceous Pierre Shale in Jefferson County, Colorado. The layer heaved with a differential displacement of 3 inches within 24 hours after a rainstorm at this construction site. Note the hump in the fence aligned with the trend of the bentonite layer. Heaving bedrock damage is occurring in the subdivision in the background.