Comparisons of One-Dimensional Consolidation Characteristics of Clays by Using Two Different Specimen Sizes

摘要

One-dimensional consolidation properties are important for prediction of time-dependent settlement of soft clay deposits. Soft clay samples are usually retrieved by the standard thin-wall sampler having a diameter of 3 in. (75 mm). Due to urgency of soil exploration and lack of this standard thin-wall sampler, some samples are collected by smaller thin-wall samplers, and therefore, cannot be accommodated by the standard consolidation ring. This research studies on effects of specimen size on consolidation properties of soft Bangkok clays by focusing on comparisons of test results between the two different sizes which are: ⅰ) d60 (60 mm in diameter and 20 mm in height that meets the ASTM D2435); and ⅱ) d35 (35 mm in diameter and 20 mm in height; newly developed in this study). Parameters which have been compared are: coefficient of consolidation, c_v, compression index, C_c, swelling index, C_s and preconsolidation stress, σ'_(pc) . From the test results, the difference in specimen's size insignificantly affected all parameters studied.