The purpose of this book is to provide guidance on ground improvement for civil works and military programs projects. It contains an up-to-date overview of ground improvement techniques and related considerations. It addresses general evaluation of site and soil conditions, selection of improvement methods, preliminary cost estimating, design, construction, and performance evaluation for ground improvement. This book should be used as a resource during planning, design, and construction for new projects as well as a reference to guide more detailed design efforts for modification of existing projects. Ground improvement is the modification of existing site foundation soils or project earth structures to provide better performance under design and/or operational loading conditions. Ground improvement techniques are used increasingly for new projects to allow utilization of sites with poor subsurface conditions and to allow design and construction of needed projects despite poor subsurface conditions which formerly would have rendered the project economically unjustifiable or technically not feasible. More importantly, such techniques are used to permit continued safe and efficient operation of existing projects when major deficiencies become evident or where existing projects are likely to be subjected to loads greater than original design or as-built capabilities.