Enhancing Problematic Soils Using Waste Materials as Stone Columns

Nowadays, the rapid population growth and economic development have made the finding of construction lands in good conditions more and more difficult. Usually encountered soil problems are excessive settlement in soft clays, low bearing capacity and liquefaction in fully saturated loose sands. To mitigate such problems, ground improvement alternatives become the best option, technically and economically. In recent years, ground improvement methods have undergone significant developments and their use in construction projects has increased over the years. Among the various ground improvement methods, stone column application is considered to be one of the most practical and economical ground improvement techniques. Stone columns are used to enhance the bearing capacity of poor ground and reduce the compressibility of soft clays. The aim of this study is to evaluate the effectiveness of stone column on the compressibility of soft clay; settlement and densification of loose sand for higher bearing capacity value. The study also provides guidelines for the selection of the most effective and economical material for stone column construction. In the study, waste materials from different construction sites were selected: crushed bricks and crushed waste concrete and the stone columns were constructed with these recycled materials. Crushed stone were also used as a third stone column material. Load-settlement response of the single and group of stone column reinforced and unreinforced soils were determined under the same loading condition. It was found out that the use of selected waste materials in the construction of stone column is promising. They resulted in very good improvement in the compressibility and the load bearing capacity of the soft clay and the loose sand. As a conclusion, these easily available waste materials can be