Engineering geology of the Selçuk (İzmir) province

ABSTRACT Geological and geotechnical properties of settlement area of Selçuk (İZMİR) was given in this thesis. This study was realized in two stages : Firstly, land use map of the Selçuk settlement area was prepared by cousidering its suitability from settlement. The objective of urban planning is to reduce the number of conflicts and adverse environmental impacts so that the quality of life and general welfare of the community are improved. For this purpose it was made the bearing capacity analyses, determinited the soil index properties, locations of faults which are controlled the tectonics of the study area, stream beds, erosion, seismic activity of the region and liquefaction potential assessment of the ground depends on the seismic activity. Additionaly, every each layer above mentioned was assessed by using GIS (Geographical Information System). Secondly, effect on anisotrophy of the metamorfic rocks in the eastern and southern of the Selçuk settlement area was investigated by considering the directions of schistosity and foliasion place (weakness zones) into rocks (Foliation in a metamorfic rock, which is typical developed in gneiss, is a most conspicuous feature). Selçuk formation which belongs to Late Cretaeous (Campanien Maestrihten) aged Menderes Masif Group rock is located at the base in the study area. Upper Cretaeous aged rocks which named as "Izmir - Ankara Zone" overlie the basement by trust VIIIfaulting. Neogene aged sedimantary rocks, overlie the "Izmir - Ankara Zone". Quaternary aged slopwash/alluvium overlie discordantly all formations in the field. Schist and marbles are commonly seen in Selçuk Formation and sandstone-mudstone intercalations named as "Izmir - Ankara Zone" and limestone, marl claystone and conglomerate are represented by Neogene aged sedimantary rocks. Alluvium which outcrops in the field commonly has a thickness of 15-75 meters. Geomorphology of the study area, controlled by rock type, tectonic activities and climate. Generally inclined slopes covered by Menderes Masif and plain areas are covered by alluvium. Mineralogical and petrographical test results of the metamorphic rock specimens which were taken from eastern part of the Selçuk settlement area are given below; 1) Chlorite Fillite, 2) Metaquartz gravelstone, 3) Chlorite Albite Schist, 4) Muskovite Quartz Schist, 5) Amphibolite. Considering the dip and dip direction of the schistosity and foliation planes of the rocks mentioned above, mechanical and elastical properties of them were determined and results of these tests were given as graphs. As a result, orientation of the discontinuities (horizontal, vertical and oblique) and anisotrophy effects on the physicomechanical properties of the different types of metamorphic rocks were determined. In considering the curvature length of the functions belong to the amprical relation between uniaxial compressive strength and discontinuity angle (discontinuity angles have a position of vertical, oblique and paralel to the loading direction), amphibolite, quartz, metaconglomerate and chlorite albite schist have shown more effect of anisothrophy then the other rock types. The order of the tensile strength of the rocks mentioned above is harmony to the uniaxial compressive strength. The ratio of (av/ah) is expressed as the coeficiant of anisotrophy (Ia) in this study and this effect is investigated. According to these analysis, it is determined that the effect of anisotropy in chlorite phyllites and quartz metaconglomerates are less than the other metamorfic rocks exposed in the field. IXAdditionally, typically maximum when oc is parallel or normal to the schistosity and foliation planes. It is determined that a relation generally exists as mentioned below ; averticai > ^horizontal. It has a minimum value when discontinuity angle (a°) is about 30°-42°. The implication of this type of curve is that sliding along the schistosity and foliation planes significantly reduces specimen strength when they are favorably orientated. By using corrected SPT-N' values, confidence conditions of the buildings in the Selçuk Municipality settlement area were determined under the static conditions. Faults are not considered while calculating these analysis. Selçuk is located within a First Degree Eartquake Zone (highest hazard) of Turkey according to the seismic design code. The seismicity of the area and its vicinity is mainly controlled by the Küçük Menderes graben faults. In this thesis, some of the buildings which are not suitable for settling considering the shear strength value against confidence factor "3". Soil liquefection potential assesments of the ground has been determined in siltly- clayey and fine sand levels. As a result of the analysis, in the areas representing the boreholes which named as SK-1, SK-3 SK-14, SK-15 SK-18, SK-20 SK-23 and SK- 26, it is determined that there is existing in soil soil liquefaction potential. Slope zoning maps have been prepared and slopes with 20 degrees are also determined. Slopes which have larger number than %36.4 inclination (steep slopes) is seen in Menderes Massif and metaserpantine and amphibolite type rocks were determined as " unsuitable areas" and shown on the engineering geological maps. As a result of this investigation, land use map of the Selçuk settlement area is obtained. Land use map of the Selçuk municipality settlement area were divided into three zone; as a provisional, suitable and and unsuitable areas for settlement purposes. X