Sina Ghani - MSc, Civil Engineering Department, Geotechnics, Kharazmi University, Tehran, Iran,
Fatemeh Izadian - Bachelor, Civil Engineering Department, Arak University, Arak, Iran,

One of the methods for improving the engineering and environmental properties of soft and contaminated lands is using the mixing methods, especially deep mixing method. This method has different practices, including dry deep mixing method, wet deep mixing, mechanical wet deep mixing method, and hybrid deep mixing method. It is difficult to select one method among them, and the desired method should be selected based on need.The term deep soil mixing refers to a method in which the stabilizing material, such as cement or lime, is mechanically mixed with soil using a hollow shaft drill. The process of mixing the soil generates a uniform column (with a constant width) from the soil and the additive. With the overlaps of the columns before the complete stroke, the adjoining walls below the ground floor can be constructed. The aim of the soil mixing is to achieve the modified geotechnical parameters such as compressive strength, shear strength and permeability. This method is also used in environmental fields to limit or stabilize harmful chemicals in the soil. In this research, we explain the advantages and disadvantages of each method to select the desired method easily. We also describe a number of methods for evaluating the soil deep mixing quality and their applications.

deep mixing, mixing quality evaluation, improvement of engineering properties, soft lands