International Perspectives on Quality Assessment of Deep Mixing

A wide range of in situ techniques has been developed in the last two decades in Europe and Asia to assess the quality of deep mixed soil columns. These methods use either conventional or specially designed tools to penetrate into the hard columns (such as pushing, pulling, rotary, driven, or displacement methods); or use geophysical concepts (such as seismic, resistivity, and echo-pulse methods). The main objective of this paper is to present the results of an international survey conducted for the quality assessment of deep mixed columns. The objectives were (a) to identify the most commonly accepted field methods of quality assessment practiced in different parts of the world, and (b) to understand the operational problems occurred when the method was applied for deep mixing projects. The respondents of the survey had diverse backgrounds, which included engineers, academicians, researchers, and contractors. The summary of the international survey provided valuable insights for the selection of in situ techniques for the quality assessment of deep mixing projects.