Mudurnu-Göynük Karayolu'nun Bozcaarmut Kesimindeki Dolgu ve Doğal Şevlerin Duraylılığı

Abstract

In the Bozcaarmut section of the Mudurnu-Göynük State Highway, an instability occurred in the road embankment and underlying geological unit, and a part of the road was damaged. In this thesis, it was aimed to investigate the stability of natural and embankment slopes in this area and its surrounding for a route of approximately 200 m where the same filling material was used. For this purpose, borehole data previously made in the study area was compiled, and in field studies, the borders of the filling materials, slope debris and marl geological units was determined, in-situ observations and measurements was made, and disturbed and undisturbed samples was taken and transported to the laboratory. In order to determine geomechanical parameters, laboratory experiments were carried out by considering the related standards and suggestions, and by using the obtained results and theoretical and empirical failure criteria the physical and strength properties of the embankment and geological units were determined. By applying back-analysis of the instability in the field, assessments were made for material parameters and water conditions during sliding. At the last stage, static and pseudo-static slope stability analyses were performed for the geological sections representing the study area by regarding two-dimensional limit equilibrium methods. The analyses for both the current situation and in the case of placing limestone crushed stone instead of marl crushed stone were done. As a result of these studies; for the current situation, it was determined that any instability problem will not be expected in the marl rock mass along the road route in the study area and the most critical failure surfaces can develop in the fill material and slope debris in circular or non-circular models. If drainage measures are taken, it was determined that instability will not be expected in the southwest and northwest sections of the existing slopes but the slopes in the central sections of the route are not safe. In the case that the marl crushed stone filling material is removed and limestone crushed stone is laid, it was understood that there will not be instability problem in the areas except the middle parts of the study area under static conditions or in the presence of seismic effect. In the middle sections of the investigated area, it was concluded that slopes cannot be considered safe in the presence of seismic effect and additional measures for reinforcement should be taken.