The Arkansas River carved a wide floodplain through Little Rock, leaving behind a complex stratigraphy of overconsolidated clays, loose alluvial sands, and shale bedrock that can appear at highly irregular depths. When a contractor opens a 25-foot cut downtown for a new parking garage adjacent to a century-old masonry building, the margin for error essentially disappears. The alluvial deposits in the Riverdale area and near Murray Park behave one way under dewatering, while the shale formations underlying the Heights can react quite differently to stress relief. We deploy automated total stations recording prisms at 15-minute intervals and vibrating wire piezometers tracking pore pressure decay in real time, feeding data into a cloud-based dashboard that the structural engineer and the owner’s rep can access simultaneously. This approach, rooted in the observational method described by Peck (1969), allows the design team to verify that wall deflections stay within the thresholds set during the deep excavations analysis phase.
Real-time deflection data from an excavation on Markham Street prevented a costly utility strike when the inclinometer showed unexpected movement at 18 feet depth.
