The works consist of the excavation and levelling of embankments for tanks and pipe-racks of a refinery in Aliaga (Turkey). The detailed design included all the geological aspects and the geotechnical characterization of the soils, which are a preliminary activity for the stability calculation of the slopes. The slopes, up to 40m high, are reinforced with spritz-beton and soil nailing.

The chemically aggressive environment required the application of a special methodology for the protection of the soil nailing bars through the preliminary injection inside a specifically prefabricated casing.

The location of the refinery, near the city of Izmir, is characterized by very high seismicity and a short distance from active faults. It was then necessary to perform a Site Response Analysis, also to determine the preudo-static loads for the design of the slopes and the retaining walls. Such walls, which have reinforced soil structures behind up to 20m high, were designed by subconsultants with the seismic parameters provided as input by ENSER.

Finally ENSER has designed the excavation slopes consolidated by soil nailing under very high seismic loads (with Peak Ground Acceleration sometimes larger than 1g). The calculation was carried out with dynamic models based on the Finite Element Method.