Experimental investigation of physico-mechanical properties of medium-low compressible soil of high-speed railway

A series of laboratory soil tests were carried out based on the undisturbed medium-low compressible soil sampling from the test field in Anqing along Ning-an passenger dedicated line. Statistical analysis for physico-mechanical properties of medium-low compressible soil was conducted to investigate the correlation between physical properties and the distribution pattern of soil properties. High pressure consolidation test, long term compression test, and triaxial compression test were employed, respectively, to study the over consolidation characteristic, long term compression behavior, and the effect of structure character of clay on soil strength. The test results obtained in this study clearly showed that good correlation could be established for partial physical properties and most of the soil properties concentrated in the first half of the distribution interval. The preconsolidation pressure was quite large, leading to the remarkable over consolidation characteristic. The compression behavior was dominated by elastic deformation under the reload pressure that was smaller than preconsolidation pressure. The primary consolidation accounted for the major proportion and steady deformation could be achieved in short time in the long term compression tests. Effect of structure character of clay on the strength of undisturbed medium-low compressible soil samples could be significantly reduced through the saturation and consolidation process in triaxial compression tests. ©, 2015, Editorial Office of China Civil Engineering Journal. All right reserved.