CS31G - Concurrent Session 31G: Case Study: The Effects of Hot Temperatures on Deep Mix Method Seepage Barrier Construction

This paper presents a case study of qualitatively measuring the impacts of hot weather on cementitious cutoff wall seepage barriers. In the Sacramento River East Levee Contract 3 Project, Deep Soil Mixing (DSM) Deep Mix Method (DMM) was deployed which used a grout mixture of Portland cement, bentonite, and water. Grout slurry is injected into the ground and mixed with the surrounding soil creating a soil-cement-bentonite cutoff wall. Specifications for maintaining the grout mixture under 90°F were developed with concern for the potential negative effects on strength and permeability of the cutoff wall. American Concrete Institute (ACI) code and ASTM’s are the standards that most cement grout applications are required to adhere to. However, there are no applicable codes that fully address the use of cement in seepage cutoff walls. The data obtained from this case study indicates a lack of strong evidence to support more rigorous temperature control requirements for DMM grout mixtures in the Sacramento Region.