In order to resolve the frost-heave problem of highway foundation,firstly,the author discussed the law to frost heave of highway roadbed and gave an analysis on its influencing factors,such as soil,water and temperatu...In order to resolve the frost-heave problem of highway foundation,firstly,the author discussed the law to frost heave of highway roadbed and gave an analysis on its influencing factors,such as soil,water and temperature.Meanwhile,sand clay and silt are given a classification according to frost heave ratio.Secondly,the roadbed frozen damage shows to frost heave and froze boiling based on the frost heave law and its influencing factors.In addition,taking some highway as an example and some principle suggestion was given through the theory on providing frostbite methods for highway foundation frost heave in seasonal frozen area.Specially,an effective method,STYROFOAM extruded polystyrene foam was introduced.展开更多
Pipes,especially buried pipes,in cold regions generally experience a rash of failures during cold weather snaps.However,the existing heuristic models are unable to explain the basic processes involving frost actions.T...Pipes,especially buried pipes,in cold regions generally experience a rash of failures during cold weather snaps.However,the existing heuristic models are unable to explain the basic processes involving frost actions.This is because the frost action is not a direct load but one that causes variations in pipe-soil interactions resulting from the coupled thermo-hydro-mechanical process in soils.This paper developed and implemented a holistic multiphysics simulation model for freezing soils and extended it to the analysis of pipe-soil systems.The theoretical framework was implemented to analyze both static and dynamic responses of buried pipes subjected to frost actions.The multiphysics simulations reproduced phenomena commonly observed during frost actions,e.g.,ice fringe advancement and an increase in the internal stress of pipes.The influences of important design factors,i.e.,buried depth and overburden pressure,on pipe responses were simulated.A fatigue cracking criterion was utilized to predict the crack initialization under the joint effects of frost and dynamic traffic loads.The frost effects were found to have detrimental effects for accelerating fatigue crack initialization in pipes.展开更多
文摘In order to resolve the frost-heave problem of highway foundation,firstly,the author discussed the law to frost heave of highway roadbed and gave an analysis on its influencing factors,such as soil,water and temperature.Meanwhile,sand clay and silt are given a classification according to frost heave ratio.Secondly,the roadbed frozen damage shows to frost heave and froze boiling based on the frost heave law and its influencing factors.In addition,taking some highway as an example and some principle suggestion was given through the theory on providing frostbite methods for highway foundation frost heave in seasonal frozen area.Specially,an effective method,STYROFOAM extruded polystyrene foam was introduced.
文摘Pipes,especially buried pipes,in cold regions generally experience a rash of failures during cold weather snaps.However,the existing heuristic models are unable to explain the basic processes involving frost actions.This is because the frost action is not a direct load but one that causes variations in pipe-soil interactions resulting from the coupled thermo-hydro-mechanical process in soils.This paper developed and implemented a holistic multiphysics simulation model for freezing soils and extended it to the analysis of pipe-soil systems.The theoretical framework was implemented to analyze both static and dynamic responses of buried pipes subjected to frost actions.The multiphysics simulations reproduced phenomena commonly observed during frost actions,e.g.,ice fringe advancement and an increase in the internal stress of pipes.The influences of important design factors,i.e.,buried depth and overburden pressure,on pipe responses were simulated.A fatigue cracking criterion was utilized to predict the crack initialization under the joint effects of frost and dynamic traffic loads.The frost effects were found to have detrimental effects for accelerating fatigue crack initialization in pipes.
