Old River: Foundation Design

The low-sill structure, the overbank control structure, and the navigation lock that are being constructed for the diversion control of the Old River are founded on a variety of soil types that are typical of those found in the lower Mississippi River alluvial valley. Detailed descriptions are given of the foundation conditions for the low-sill structure, which is a gated weir having its base approximately 50 ft below the ground surface and which is founded on silty soils that extend another 50 ft below the structure. Important considerations in design were excavation dewatering, seepage control, design of pile foundation, and preload fills at the abutments to minimize settlements.