عنوان مقاله [English]
نویسنده [English]چکیده [English]
Compressibility characteristics of fine-grained soils are often the most important parameters for settlement evaluation of the founded layers. The compression index which is the slope of virgin curve is usually for determination of settlement potential of fine grained soils. In this research, the effects of different physical and index properties of soil samples were investigated on compression index in order to find the most compatible properties and reliable equation based for a wide range of soil samples collected from different sites of Iran. For this purpose, one-dimensional consolidation tests were conducted utilizing conventional oedometer test on 26 soil samples at three different levels of void ratio. The compression index of each specimen was determined using data obtained from test results and correlation analysis was made using statistical software, SPSS. The results showed that the compression index, , has a significant correlation with the most of index properties where its coefficient of correlation with structural properties was strongly greater than those related to inherent properties. Therefore the empirical equations which do not consider at least one structural parameter and use only intrinsic properties could not estimate the compression index properly. Furthermore a very simple and reliable equation was developed for estimation of the compression index and virgin curve of unconsolidated and normally consolidated fine-grained soils. Statistical analysis demonstrated that the proposed relationship predicts the compression index accurately in comparison with the existing relationships.