Study on stability of optimized structure of subgrade in transition section of road and bridge in permafrost region
Since the Qinghai-Xizang Railway started operating,the subgrade problems caused by frost heave,thaw settlement and other diseases are more serious and complex than those in ordinary areas. As an important link between road and bridge,the settlement difference between subgrade and abutment seriously affects the safe-ty of railway operation and driving comfort. Combined with the treatment methods of differential settlement in the transition section in general areas,starting from the stiffness difference,and considering the characteristics of the active layer of frozen soil,this paper puts forward the optimized structure of the transition section of pile foundation road and bridge,so as to achieve the smooth transition between the stiffness of subgrade and abut-ment,and analyzes the long-term effect of the optimized structure. The results show that after embedding two rows of four concrete pile foundations in the transition section subgrade,under the continuous external load and cyclic temperature load,the concrete pile foundation has little effect on the frozen soil temperature field,which can ensure the good stability of frozen soil. The differential settlement of subgrade and abutment and the rail sur-face angle are greatly reduced. In the global warming environment,through ANSYS simulation and analysis of temperature field and displacement field,it is found that the concrete pile foundation has little influence on the temperature field of subgrade at the transition section,and the treatment effect for differential settlement is very significant.
railway subgraderoad and bridge transition sectionexperimental studyQinghai-Xizang Railway
万方数据
维普
