Influence of Pressure Grouting on the Anchors Carrying Capacity in Fine Grained Soil

The main purpose of this paper is to analyse the influence of pressure grouting on ground anchors pull out capacity in fine grained soils, using the finite element method (FEM). The grouting process is simulated by volumetric strain of grout body, which is determined from excavated test anchors. Three constitutive models (Mohr-Coulomb, Hardening soil model and Hypoplasticity model for clay) are applied. Obtained pull-out capacities for the cases with respectively without grouting simulation are compared with the results of appropriate analytical and empirical methods. Cylindrical cavity expansion theories are also applied for the purpose of results evaluation. The influence of consolidation process after pressure grouting simulation and the value of volumetric strain are later analysed. It can be concluded that pressure grouting simulation has a substantial effect on the anchors pull-out capacity. Consolidation analysis following grouting simulation turned to be an important factor. Results from study, in which volumetric strains were varied, confirmed that the influence of grouting diminishes with increasing volumetric strain/grouting pressure.