In Situ Techniques for Quality Assurance of Deep Mixed Columns

Due to variations in mixing procedures and environmentally related soil factors in laboratory and field conditions, strength properties of deep mixed soil columns are different from the design strengths obtained from laboratory tests. Hence, there is a need to assess deep mixing (DM) operations in field conditions prior to infrastructure construction. For quality assurance, in situ intrusive methods are preferred over field sampling and laboratory test methods since the in situ methods are repeatable, reliable, and quick. This paper presents various intrusive in situ methods including standard penetration test, cone penetration test, pressuremeter tests and various other field test methods and their applications in quality assurance studies of deep mixed columns. Advantages and limitations of these methods are discussed. Future research needs for better evaluations are mentioned.