Prediction of swelling behavior of expansive soils using modified free swell index, methylene blue and swell oedometer tests


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2016

Öğrenci: AMİR JALEHFOROUZAN

Danışman: ERDAL ÇOKÇA

Özet:

Expansive soils are recognized as problematic soils that impose several challenges for civil engineers. Such soils undergo significant volume change in case water penetrates into them, and they shrink as they lose moisture. Lightly-loaded engineering structures such as pavements, single story buildings, railways and walkways may experience severe damages when they are founded on such soils. Determination of expansive soils and quantifying their swelling potential and pressure caused by their expansion are essential in geotechnical engineering. Therefore it is necessary to develop models to predict swelling pressure and swelling potential of expansive soils. This research presents an experimental investigation of swelling behavior (swelling pressure and swelling potential) of expansive soils. The expansive soil specimens were prepared in the laboratory by mixing kaolinite and bentonite at different percentages. Atterberg limits, Grain size distribution, , Optimum water content, Maximum water content , Swelling pressure, Methylene blue value (MBV), vi Modified Free swell index (MFSI) and swell potential of the mixtures were assessed. The correlations between the swelling behavior of test samples and fundamental properties of test samples were studied. Additionally, the correlations between swelling behavior and MBV, MFSI and some of the index properties of test samples were investigated. These tests were repeated on the natural expansive soil samples and the results were evaluated. As final conclusion of this research, the values of swell pressure and swell potential of the test samples from the experimental investigation are compared with the predictive values of the same based on currently proposed and other suggested models.