Study On Dynamic Property Of Cemented Silt Subgrade Subject To High Speed Train

According to the problem of delay time compacting appearing in subgrade construction to soil-cement of passenger traffic, the paper proceeds a research on physical and mechanical property and dynamic property of cemented low liquid limit silt compacted in different delay time and subject to freezing and thawing cycles wetting and drying cycles.Firstly, based on the on-site construction work related to compaction, compaction property of different delay time to cemented low liquid limit. On the base of above, wetting-drying and freezing-thawing test would be employed, and then influence law of Delay time, times of wetting-drying and freezing-thawing to strength of the soil-cement were studied.Secondly, based on the cyclic triaxial tests on cemented low liquid limit silt subject to different delay time ,freezing and thawing cycles and wetting and drying cycles,Effects of delay time and times of wetting-drying and freezing-thawing on dynamic strength , dynamic modulus, dynamic deformation and interstitial hydraulic pressure were studied. At the same time, critical dynamic stress and stiffness degenerate strain were presented.Thirdly, through experimental investigation, stress-strain relationships of the soil-cement were researched and then dynamic modulus and damp varying with dynamic strain to the soil-cement subject to different delay time ,freezing and thawing cycles and wetting and drying cycles were gained.Finally, by means of one half analysis theory and finite-element method, track–subgrade coupling vibration model were established and based on the model, dynamic property of subgrade were studied. It indicated that it is of engineering importance to considering the delay time ,freezing and thawing cycles and wetting and drying.