Investigation of geoengineering properties of clays of Erenler (Afyonkarahisar) region

In this study, carried out in the Erenler Region of Afyonkarahisar province, the geoengineering properties of the clayey levels of the Quaternary aged contemporary sediments were investigated. The study, it was aimed to reveal the possible engineering problems with the horizontal and vertical continuity of the units in the region, the change of engineering properties, with the field, laboratory, and office studies, in addition to the construction works in the region. Paleozoic aged Afyon Metamorphites are located at the base of the study area. The Middle-Upper Miocene aged Ömer-Gecek Formation unconformably overlies the Afyon Metamorphics. The Upper Miocene aged Erkmen volcanics are the end product of the volcanism that occurred in the region. Quaternary alluvium overlies all previous units with angular unconformity. In addition to the construction works, 57 additional drillings with a depth of 2.5 m were made to examine the soil properties, and 275 disturbed samples were taken. Within the scope of laboratory studies, particle size distribution, consistency limits, X-ray diffraction (XRD), and triaxial compressive strength tests were carried out from the samples taken. In conclusion; It has been determined that 20 m of the Quaternary fill in the study area consists of well-poorly graded brown clayey sand, green clayey sand, dark brown sandy silty clay, yellow sandy silty clay, and filling units from bottom to top. With the additional studies, it was understood that the foundation soil was composed of dark brown clay, light brown clay, brown clay, light yellow sandy silty clay, and yellow sandy silty clay from bottom to ceiling. According to the results obtained from the laboratory studies, the ratio of gravel is between 0% and 8%; the silt+clay-sized fine-grained material ratio is between 11% and 98%, soil classes are generally CH and CL, occasionally SC, SW-SP, ML, and MH soil classes. In mineralogical analyzes performed by the X-ray diffraction (XRD) method, it was determined that the dominant clay types were chlorite and illite-mica. The fact that the groundwater level is at shallow depths, especially the density of clay minerals with high swelling potential, indicates that swelling/settlement and stability problems may be encountered in the region.