BAUER Foundation Corp., the US subsidiary of BAUER Spezialtiefbau GmbH, has previously been involved in the maintenance of several sections of the Herbert Hoover Dike on behalf of the U.S. Army Corps of Engineers (USACE). Now Bauer has once again been commissioned with the execution of approx. 13.5 km stretch of cut-off wall. Due to dense soil and the presence of organic materials, this construction phase first requires pre-drilling using the Kelly drilling and continuous flight auger method before the actual cut-off wall can be produced using the cutter soil mixing method. In this method the characteristics of cut-off wall technique and the mixed-in-place method – where the existing soil is used as aggregate – are combined. The subsoil is also stabilized using jet grouting.