Dry Soil Mixing at Jewfish Creek: Fid-Bau Portal

Dry Soil Mixing at Jewfish Creek

Burke, G. K. / Sehn, A. L. / Hussin, J. D. / Hull, V. E. / Mann, J. A.

United States Highway 1 (US1) is known as the Overseas Highway in the Florida Keys and is the main road serving these islands. This 2-lane highway traverses the Jewfish Creek Drawbridge and is the main throughway for travelers to and from the Keys. Florida DOT, motivated by hurricane preparedness and public safety, is replacing the drawbridge at Jewfish Creek with a fixed bridge and widening the roadway north of the bridge: The widening scheme involves improving the soft underlying soils at the site with a technique known as dry soil mixing (DSM). Choosing the appropriate binder depends on the soil to be mixed, and in various applications can be a variety of materials including cement, fly ash, slag, lime, and other additives. Likewise, no single piece of equipment will be best suited for all applications and soil types, and for this reason mixing tools are often developed for individual projects. Additional design issues revolved around quality assurance and quality control (QA/QC). A unique program and testing methods were developed by project engineers to ensure that the product met the owner's requirements and project specific specifications. The DSM process is presented from the viewpoint of the engineer and the contractor. Topics of discussion detail the steps engineers followed to determine the applicability of DSM, and include design considerations, laboratory and field testing, reagent binder design, construction methods/procedures, QA/QC, equipment, and performance monitoring.