Abstract:
Permeation grouting is a cost-effective and environmentally compatible method for soil improvement and is therefore becoming more and more important. Unfortunately there is a lack of knowledge among geotechnical engineers about the mechanical behavior of grouted soil. In particular, the determination and verification of strength and stiffness properties after grouting has not been resolved. As a consequence, a research project has been carried out to improve the understanding of the mechanical behavior of grouted granular soils. In the framework of this project, extensive laboratory testing on grouted soils and three large scale field tests have been carried out to improve the understanding of the mechanical behavior of grouted granular soils. Using a special soil sampling technique, it was for the first time possible to obtain high quality soil samples from a grouted granular soil for further laboratory testing. The current paper gives an overview about the large scale field tests and presents the results of triaxial and uniaxial compression tests on grouted soil samples, performed to better understand the factors influencing the strength of the improved soil. Based on a new method determining the cement content of the grouted soil, fundamental correlations for strength and stiffness parameters are proposed in order to facilitate the verification of grouting works in future.