Geotechnical assesment of the settlement problems in İzmir Atatürk Organized İndustrial Zone

Izmir Ataturk Organized Zone (IAOIZ) is located at the North of Izmir Bay on the alluvial fan sediments of Gediz Delta. Initially, the delta of the river has been changed, and after that fills, which reach to 3m. hight, have been constructed after the application of ground improvement methods. After this phase, the construction of industrial facilities was completed. The active facilities supplied the water necessity by opening several boreholes. As the water necessity is supplied by the underground water sources, settlements which are about 2-3 m. are observed in IAOIZ persistently, ıt is inevitable that the ground water level will decrease far beyond the level of -1,40 m. both in the reconstruction and the border line of the decreasing freatic line. In this case, there will be an extra load of 1,0 t/m2 per meter of the decreasing water level and the normally consolidated layers will be re-consolidated. As the main problems arise from the decrement of the water level rather than the loads derived from the constructions, the risky over pumping technique must be abandoned. In the light of the surveys and investigations, it is seen that the settlements are not related with the construction loads, generally, there is settlement in the whole area. The main reason of the settlement is the decrement of the piezometric water level from -5,0 m. to -55.0 (according to 2001 data). Keywords: Settlement, Soil, Borehole, Consolition, Ataturk Organized Zone