Geological and geotechnical examination of Batman province Gültepe Bridge

In this study, geological and geotechnical investigations were conducted regarding the vertical change and engineering aspects of the surface where the bridge in Batman province, Gültepe Quarter. In this regard, physical and mechanical parameters of the units were detected and the results were evaluated by conducting Sieve Analysis, Triaxial Compression tests within the laboratory experiments on undisturbed specimen (UD) of Standard Penetration Test (SPT) taken by drilling four basic wells in order to detect the lithological and geological conditions, and engineering parameters of the surface in the area of investigation. The potential geological problems such as liquefaction and settlement which may occur in the area of investigation were analyzed with PLAXIS computer software and the results were discussed. There are alluviums geologically containing clay, conglomerate, sand and gravel in the central settlement area of Batman province (around the investigation area). There are also silty clay and silty sand layers on the ground of Gültepe neighborhood, the investigation area and a liquefaction analysis were conducted with geologic measurements and by employing the approach of Dobry et al. (1981) since groundwater was discovered in the drilled wells, it is a loose unit mostly with 5-10 meters of sand and it is considered that this unit may trigger the risk of liquefaction by affecting the groundwater. In the liquefaction analysis conducted, safety factor (Fa) was found as 0,95765764, it was identified that there is a risk of liquefaction due to safety factor being lower than 1, and the analysis was also supported with PLAXIS computer software. In this study, the settlement and stress which may occur in the base of piers of bridge in the investigation area were analyzed by using PLAXIS computer software and the models created were compared by correlating with the other acquired data. In the area of investigation, ΔH=11,93-12,32 cm settlement in 2,00 meters and ΔH = 7,09-8,55 cm settlement in 4.50 meters were identified in the consolidation settlement calculation conducted according to Bowles (1988). In the second phase of the study, consolidation settlement analysis was performed by using PLAXIS computer analysis. As a result of the acquired models, 1,70 cm of settlement was identified and the models were evaluated by correlating with the results of consolidation settlement analysis performed according to Bowles (1988). In order to determine the geological problems in the investigation area and in case of its probability, Bored Pile technique, which is one of the soil improvement measures, has been applied and discussed.