Acceleration of the consolation in road fillings on soft floors

It is a known fact that the bearing capacity and the settlement problems are often encountered when the transportation structures are built on soft soils. In such structures, the spaces of the investigation points are considerably higher than the building type structures, and after the design according to the drilling and probing results, small or medium sized unforeseen problems may sometimes be revealed. When the soil is too soft, the sudden failures of soil may be encountered. In the case of increasing compressibility, it is possible to fill up continuously to compensate long-term settlements. In addition to continuous repair costs, the deterioration of comfort can at least be encountered during the travel. If the thickness of soft soil is low and close to the surface, it is possible to change this soil layer; if the thickness of the soft soil is high, there are many different options such as restriction of the soil with walls or to accelerate the consolidation with drains In this study, the solutions of the problems which are caused by a 2 m high embankment in a section consisting of very soft soil are examined. In Sinanoğlu region, which is on the fifty km-long Adapazarı - Karasu double road, 2 m high embankment led to over one meter settlement and the breakage of the culverts on the two hundred meters long part of this road. The observations made after the road construction finished show that the road had closed for service for many times. In this paper, in a similar section, using the Plaxis 2D software, firstly, the problems of bearing capacity and settlement are presented in the natural condition, and then the alternative solutions are presented and the results are examined. In the analyzes, the effect of the parameters such as the construction speed of the embankment, the consolidation time and the presence of drains on the results are researched and it is aimed to determine the appropriate solution depending on the thickness of the soft soil under the limited thickness of the embankment.