The Rapid Disaster Infrastructure Missouri River Levee System L-536 project is well underway after a major innovation—using eight, 30,000 to 40,000 square foot heated tents to warm the clay used to build the levee system. The setback levee is about 4.3 miles long and ties into the existing creek levees on either side. The contract with the U.S. Army Corps of Engineers (USACE) Omaha District also involves replacing a mile of levee damaged by flooding in 2019.
Winter work has presented one major challenge: clay, the cohesive material used along the outside and cap of the levee, has been wet and cold. To allow for successful placement and adherence between soil layers, the clay must be at a certain temperature.
To combat this challenge, the team harvests frozen soil from multiple borrow sites and thaws the material in heated tents to the required specifications. By disking the material, more air flows over the soil, allowing it to dry quickly. In addition to heating the clay itself, the team places glycol-heated blankets on the ground before they place the material. Thus, both the ground and the material placed are warmed, allowing for improved adhesion between layers.
This process has involved a massive geotechnical effort, requiring the use the use of soil proctors to ensure the soil is the correct relative density and type for compatible placement. To date, Shimmick has placed 1.3 million yards of material, processing roughly 6,000 cubic yards of clay a day through winter.
Click the link below to read USACE’s writeup on the RDI heating innovations.