The bearing capacity of ground anchors is significantly influenced by the surrounding soil and by the mechanical behaviour of the grout in the bonded length. In stiff overconsolidated clays, peak strength and strain softening leads to a non-uniform distribution of the mobilised shear strength. In order to reproduce an in-situ anchor pull out test, advanced constitutive models are employed in numerical analyses, namely a multilaminate model developed for overconsolidated stiff soils and a constitutive model accounting for strain softening for the grout. The numerical results obtained with the Multilaminate model are compared to the results obtained with the Hardening Soil Small model and to in-situ fibre optics measurements. The Multilaminate soil model was capable of reproduce the softening in the stiff overconsolidated soil and the cracks in the grout could be captured reasonably well. The strain measurements and the load-displacement behaviour were well reproduced.