Compensation Grouting in Sand: Experiments, Field Experiences and Mechanisms

This thesis reports on experimental research on compensation grouting in sand. It is investigated in model tests, how the shape of the grout bodies made during injection depends on the grout properties, the density of the sand and the way the tubes are installed. The shape of the grout body affects the necessary injection pressure and whether heave is localised to one injection point or distributed over a wider area. An analytical model is developed that shows the influence of various parameters. The evaluation of field measurements shows the influence of soil disturbance. Soil disturbance in a layer of sand may lead to a decrease in density of the sand and compensation grouting in such a layer will have a lower efficiency (a lot of grout has to be injected to create some heave) and long term settlements are possible