Geological, geotechnical, hydrogelogical and seismicinvestigation of soils in Acipayam Basin (Denizli)

A large part of the Acıpayam, 55 km SE of Denizli, is took placed in and around the Acıpayam Plain, which is shaped by NW-SE trending dip-slip normal faults. The study was carried out to determine the geological, geotechnical and hydrogeological characteristics of the settlement areas and to evaluate them in terms of urbanization. From the zoning surveys prepared before, geotechnical drillings, observation pits, drilling and observation pit data, test results of ground samples, groundwater levels in the drillings, seismic refractions and microtremor measurements data were compiled. In addition, in this thesis, 14 geotechnical drillings with depths from 8 m to 26 m at different points within the scope of the PAU-BAP project (No: 2022FBE058), and the physical and mechanical properties of the soil and rocks were evaluated. The dynamic properties of the soils, seismic refraction and microtremor measurements were made in 15 different areas. All the data yielded were transferred to the JEOKBS module of the Kumsar-Gis program, and the geological and hydrogeological logs of 87 groundwater boreholes by DSI in the plain were transferred to the GIS digital databases of the YAS-GIS module of the same software. When all data are evaluated, the propagation speeds (Vs) of the seismic shear waves for a depth of 10 m from the ground surface in the study area are between 114 m/s and 200 m/s in the inner parts of the plain, and between 200 m/s and 350 m/s towards the basin margins, by the way, the Vs30 values are between 155.2 m/sec to 413.1 m/sec. The magnification values of the soils are between 0.83 and 5.43. The swelling pressure values vary from 0 kPa to 0.5 kPa, and the swelling percentages vary from 0% to 6.2%. The soils in the area are mostly in CL and CH classes based on the combined soil class. The presence of SC group soils was determined in some boreholes. According to traditional liquefaction analysis, easily liquefiable sandy soils size are in the limited area. The static level of groundwater in boreholes are between 1m and 20 m deep. It is widely known that only sandy and sandy-silty soils can liquefy under earthquake loads. However, in the model experiments carried out in the laboratory within in the study, it has been experimentally demonstrated that liquefaction can also develop in clayey soils saturated. It is suggested that this issue should be investigated in detail through the model experiments and field applications in future studies. KEYWORDS: Acıpayam (Denizli), Geology and Geotechnics, Groundwater Drilling, Geographic Information System, Liquefaction.