Analysis And Control Of The High Embankment Settlements In Railway Yard

In recent years,in order to meet the continuous needs of national economic development,the pace of development of China's railway is moving forward from the eastern region to the central and western regions.In the process of railway construction,how to do well the settlement control of high embankment section is a very important issue.Therefore,It is an important subject in the field of railway construction technology to reduce the post-construction settlement of the high embankment and eliminate the harm of the settlement,because the post-construction settlement of subgrade is difficult to control and the settlement is relatively large.Based on the design and construction of a special railway freight station high embankment in Guizhou,according to its characteristics,the settlement analysis and control of the high embankment is done in this thesis.Main works in the thesis include:1.The stress and deformation characteristics of high embankment are analyzed from the aspects of visco-plastic properties of geomaterials,compaction characteristics of subgrade filling and change regulation of additional stress in foundation soil;2.Using the FLAC 3D finite-difference software,the stability of high embankment slope is analyzed;3.According to the soil test data and the measured stress-strain curves in the construction site,a visco-plastic constitutive model of the high embankment applying to nonlinear finite element is established.By the numerical analysis,some time-dependent stress,strain and deformation characteristics are obtained,and the influence of the post-construction settlement and differential settlement of the high embankment is analyzed on the construction period or the static load period;4.In subgrade settlement prediction,based on the monitoring data of settlement in the process of high embankment filling,a hyperbolic model,exponential curve model and Hoshino method is used to predict the post-construction settlement;in order to overcome the exponential divergence of GM(1,1)model,an improved unequal interval GM(1,1)model is proposed based on the function transformation to improve the prediction accuracy of GM(1,1);5.According to the analysis results,some comprehensive settlement control methods for high embankment are proposed.