Study on the performance of shallow soil mixing with cement

Abstract

Shallow Soil Mixing (SSM) method with a low dosage of cement can be used to create a sufficiently strong platform for quick access onto grounds that have been recently reclaimed with soft clays. The effectiveness of the SSM method is dependent on the type, dosage and dosing method of cement, the mixing blade design, and the mixing sequence. Hence, a laboratory-scale SSM apparatus was developed to simulate SSM in the field. The early strength development and uniformity of Cement Mixed Soil (CMS) were evaluated by taking into consideration (a) Type of cement: CEM I vs CEM III/A, (b) Dosage of cement: 7% vs 3%, (c) Dosing method: 1-layer vs 2-layer mixing, and (d) Mixing blade design: without overlap between mixing blades vs overlapped mixing blades. Shear strength test results demonstrated that the shear strength development of CMS at an early stage is affected by the type, dosage, and dosing method of cement, while the uniformity of the CMS is affected by the dosage and dosing method of cement and the mixing blade design. From the laboratory test results, it is recommended that CEM III/A cement with 7% cement dosage, 2-layer of dosing method and overlapped mixing blades design parameters be used for SSM in the field to achieve high early strength gain and good uniformity cement soil mix.