Effect of grouting and DMM on big construction projects in Japan and the 1995 Hyogoken-Nambu Earthquake

A number of ground improvement methods have been developed and used in civil engineering projects. On the basis of the main improving principles, five techniques, namely, displacement, dewatering, densification, solidification and reinforcement are listed. Each technique has its own advantages and is often used safely in construction works. The solidification technique is the most effective among the ground improvement methods. Grouting and Deep Mixing Method (DMM) are representative solidification techniques, and are frequently used at construction sites. In this paper, first, the classification and characteristics of these two methods are examined. Second, the applicability of the methods is briefly summarized, in particular, in terms of environmental impact. Lastly since solidification is often used in strengthening soft ground during construction works, some big Japanese construction projects and the restoration of the 1995 Hyogoken-Nambu Earthquake disaster are discussed.