Multiphysics extension to physically based analyses of pipes with emphasis on frost actions  

作　　者：Zhen LIU Xiong (Bill) YU Jun-liang TAO Ye SUN 

机构地区：[1]Department of Civil Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA [2]Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, Ohio 44106, USA

出　　处：《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》2012年第11期877-887,共11页浙江大学学报（英文版）A辑（应用物理与工程）

摘　　要：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.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.

关 键 词：Underground pipe MULTIPHYSICS Frost action Finite element method（FEM） 

分 类 号：TU431[建筑科学—岩土工程] TF821.032[建筑科学—土工工程]