A Study with a New Device on Compression Properties of Fine-Grained Reconstituted Soils

For the purpose of examining the settlement behavior of fine-grained soils, a sufficient number of one- and three-dimensional consolidation tests on ten different reconstituted soils were performed in the study. A three-dimensional consolidation test apparatus, which is considered to be a modified form of standard oedometer test apparatus and permits lateral strains to occur, was designed. The consolidation tests were carried out both with standard oedometer and with the new test device so that the effect of different displacement conditions on the test results could be compared. Oedometer tests, by using both the conventional one-dimensional and the new test apparatus, were also carried out with the purpose of understanding the effect of test apparatus on the results. According to the plasticity indexes of the samples, it was found that three-dimensional settlements were greater than one-dimensional settlements at the vertical pressures of 200–300 kPa and higher. The slopes of three-dimensional settlements’ curves were found to be steeper than those determined from standard oedometer curves at the pressures of over 150–200 kPa. When comparing the calculated compression moduli for each group of test results, it was found that the three-dimensional moduli values were 50–75 % of the one-dimensional moduli values. On all of the three-dimensional test results, performed, while the central part was being loaded incrementally, small settlements on the surrounding part were observed. During the removal of the applied loads from the central part, the small settlements reached on the surrounding part approximately remained constant.