Successful EPB tunneling strongly depends on the interaction between soil- ground-water con- ditions and the tunneling shield. This paper presents some results of a shield drive at Izmir Light Rail Transit System (LRTS) in Turkey. The first part focuses - besides a short project description - on the main soil char- acteristics and fundamental aspects of the face support. Theoretical and experimental basic-knowledge about foaming agents, polymers and their dosage will be delivered. Finally, practical tunneling experiences of the four EPB drives in Izmir will be described. An attempt will be made here to summarise the influence of the foam- and bentonite-conditioning on thrust forces, torque and costs in different kind of soils.