Importance of engineering geology on slope stability analysis applied in Northern Marmara Motorway (Section-5), İzmit, Turkey

Abstract

Abstract Northern Marmara Motorway is a project planned to reduce the heavy traffic load around İstanbul, Tekirdağ, Kocaeli and Adapazarı provinces. In the Kurtköy-Akyazı section of the Northern Marmara Motorway, within the 5th section, bordered by “the Motorway Port Connection Road” and “İzmit Junction”, flow and slide-type mass movements were observed along the route. Possible causes of these mass movements occurred in the Çaycuma Formation which is sandstone-shale alternation, and the support system to stop the movements were evaluated within the scope of the study. The existing project criteria were analysed for the static and dynamic conditions, types of mass movements and the factors causing these mass movements were determined, and the slope stabilization applications suggested. The study area was additionally evaluated in terms of hydrogeological characteristics. Therefore, a meteorological water budget for the study area has been calculated by the Penman Method. Additionally, the water budget data was evaluated in terms of the mechanism that creates the mass movement, the environmental properties and the water relationships. Stability analyses were run in terms of soil structure, soil-rock mechanics, engineering geology, geotechnical engineering, and field and laboratory test results for the mass movements that took place in the right cut slopes between KM: 170 + 300 − 170 + 400, KM: 170 + 640 and KM: 175 + 297 − 175 + 463 of the 5th section.