All over the world, habitable space in deltas and river basins is under increasing pressure from economic expansion, growing populations, subsidence and the impacts of climate change. It is expected that, within 40 years from now, about 80 percent of all people will live in deltaic regions. The Netherlands is a typical example of such an area. The geological stratification consists of typical soft to very soft soils, especially in the western part of the country. More than half of the country is located below sea level, the surface of the land is flat, and the groundwater table is extremely high. In these areas particularly it is important to understand the complex behaviour of the subsoil, consisting of soft soils, like organic clays, loose sand deposits and peat. Keeping the water separated from the land is a continuous challenge. It is important to search for solutions that draw on the potential of the coastal system, that enhance safety in densely populated coastal areas, and that minimise the ecological impact. Building and maintaining infrastructure in these areas is quite challenging. Expert knowledge of soil mechanics and geotechnical engineering is essential to reduce the risks inherent to construction on and in deltaic areas.

Soil mechanics and geotechnical engineering. Theory and practice. Both are equally important in order to create a safe and sustainable living environment for us and our (grand)children. Both theory and practice can be found in this publication. In the first part, starting from the fundamental side, the ins and outs of the complicated multi-phase material which we call soil, are explained and summarised. In the second and third part this theoretical knowledge is further developed and used to analyse a large number of specific soil-related problems, like slope stability, earth retaining structures, foundations, ground improvement, environmental impact, underground construction, coastal engineering, dike technology and so on.

The author has been active in this field for the past 40 years, well connected on the one hand to the scientific world of soil mechanics and on the other hand to the (geotechnical) engineering practice. With this book, the author has left a legacy of his wide knowledge and expertise to the younger professionals. It is particularly valuable for the geotechnical engineer of the 21st century, living and working in deltaic areas.

Peter van den Berg

Deltares, Director Geo-Engineering