The main challenge in the numerical modelling of driven displacement piles is the influence of changes of soil state parameters caused by the penetration process during pile driving on the bearing behaviour of the pile. In this work, a numerical approach for modelling installation effects was applied to back-analyze field tests in sand. After simulating the penetration of a CPT and a driven ductile iron pile, a pile load test was investigated to compare the calculated with the measured data. Although there were some simplifications, the installation effects as well as the pile bearing behaviour were satisfactorily modelled.