Consolidation settlement analysis of clay soil layers with preloading and prefabricated vertical drains

In this study, consolidation settlement analysis of a 6-storey dormitory being constructed on very soft fully saturated clay layers was calculated by means of preloading and prefabricated vertical drains. The construction site is at the district of Çatalağzı, Zonguldak. Lithology and geotechnical properties of the soil layers were determined with the help of samples taken from the drilling and observation pits in the study area. Consolidation parameters and index properties of the soils samples were obtained from field and laboratory tests. Then, all stress distributions created by the structure, the magnitude of consolidation settlement and consolidation time on soil layers were calculated with the aid of SETTLE3D V3. The numerical details of the project and ground layers were entered into the SETTLE3D Program, taking into account the construction period, the construction production was added to the time-dependent ground layers by adding 1 year and the settlement time relationships were examined after this loading. Approximate sitting values were 30 cm and sitting time was 50 years. The non-uniform baseline pressure and these settling calculations were then calculated again by the program. There was a 15% difference between these values. To reduce the consolidation time and the magnitude of the settlement, an embankment load as much as coming from the future structure was added to the land, and this production was extended over time and settlement analyzes were conducted. Prefabricated vertical drainage system were placed under the embankment at different intervals. It was made attempt to reduce the consolidation time. Then the embankment was removed and the building load was applied on the soil layers. The consolidation time were recalculated. by means of this, more than 50% of consolidation settlement occurred with preloading and consolidation time was reduced to the time of construction of building.