The coupled thermo-hydro-mechanical and chemical (THMC) processes of stress/deformation,fluid flow,temperature and geochemical reactions of the geological media,namely fractured rocks and soils,play an important role ...The coupled thermo-hydro-mechanical and chemical (THMC) processes of stress/deformation,fluid flow,temperature and geochemical reactions of the geological media,namely fractured rocks and soils,play an important role in design,construction,operation and environmental impact assessments of rock and soil engineering works such as underground nuclear waste repositories,oil/gas production and storage,geothermal energy extraction,landslides and slope stability,hydropower and water conservancy complexes,etc. This paper presents an overview of the international and Chinese experiences in numerical modeling of the coupled THMC processes for both the state-of-the-knowledge,remaining challenges and possible future prospects.展开更多
The air-flow’s states and ways acted on the technological process of chemical fiber are summed up, which includes chip drying, spinning quenching as well as airjet texturing (air texturing, tangling texturing and bul...The air-flow’s states and ways acted on the technological process of chemical fiber are summed up, which includes chip drying, spinning quenching as well as airjet texturing (air texturing, tangling texturing and bulked continuous filament (BCF)),and the effect of air-flow on the process and quality of chemical fiber is studied,and the action of mechanics and heat on the bulked continuous filament are calculated.展开更多
Although a large number of previous researches have significantly contributed to the understanding of the quasi-static mechanical behavior of cemented tailings backfill,an evolutive porous medium used in underground m...Although a large number of previous researches have significantly contributed to the understanding of the quasi-static mechanical behavior of cemented tailings backfill,an evolutive porous medium used in underground mine cavities,very few efforts have been made to improve the knowledge on its response under sudden dynamic loading during the curing process.In fact,there is a great need for such information given that cemented backfill structures are often subjected to blast loadings due to mine exploitations.In this study,a coupled thermo-hydro-mechanical-chemical(THMC)-viscoplastic cap model is developed to describe the behavior of cementing mine backfill material under blast loading.A THMC model for cemented backfill is adopted to evaluate its behavior and evolution of its properties in curing processes with coupled thermal,hydraulic,mechanical and chemical factors.Then,the model is coupled to a Perzyna type of viscoplastic model with a modified smooth surface cap envelope and a variable bulk modulus,in order to reasonably capture the nonlinear and rate-dependent behaviors of the cemented tailings backfill under blast loading.All of the parameters required for the variable-modulus viscoplastic cap model were obtained by applying the THMC model to reproducing evolution of cemented paste backfill(CPB)properties in the curing process.Thus,the behavior of hydrating cemented backfill under high-rate impacts can be evaluated under any curing time of concern.The validation results of the proposed model indicate a good agreement between the experimental and the simulated results.The authors believe that the proposed model will contribute to a better understanding of the performance of hydrating cemented backfill under blasting,and also to practical risk management of backfill structures associated with such a dynamic condition.展开更多
基金Supported by the Special Funds fo Major State Basic Research Project (2002CB412708).
文摘The coupled thermo-hydro-mechanical and chemical (THMC) processes of stress/deformation,fluid flow,temperature and geochemical reactions of the geological media,namely fractured rocks and soils,play an important role in design,construction,operation and environmental impact assessments of rock and soil engineering works such as underground nuclear waste repositories,oil/gas production and storage,geothermal energy extraction,landslides and slope stability,hydropower and water conservancy complexes,etc. This paper presents an overview of the international and Chinese experiences in numerical modeling of the coupled THMC processes for both the state-of-the-knowledge,remaining challenges and possible future prospects.
文摘The air-flow’s states and ways acted on the technological process of chemical fiber are summed up, which includes chip drying, spinning quenching as well as airjet texturing (air texturing, tangling texturing and bulked continuous filament (BCF)),and the effect of air-flow on the process and quality of chemical fiber is studied,and the action of mechanics and heat on the bulked continuous filament are calculated.
文摘Although a large number of previous researches have significantly contributed to the understanding of the quasi-static mechanical behavior of cemented tailings backfill,an evolutive porous medium used in underground mine cavities,very few efforts have been made to improve the knowledge on its response under sudden dynamic loading during the curing process.In fact,there is a great need for such information given that cemented backfill structures are often subjected to blast loadings due to mine exploitations.In this study,a coupled thermo-hydro-mechanical-chemical(THMC)-viscoplastic cap model is developed to describe the behavior of cementing mine backfill material under blast loading.A THMC model for cemented backfill is adopted to evaluate its behavior and evolution of its properties in curing processes with coupled thermal,hydraulic,mechanical and chemical factors.Then,the model is coupled to a Perzyna type of viscoplastic model with a modified smooth surface cap envelope and a variable bulk modulus,in order to reasonably capture the nonlinear and rate-dependent behaviors of the cemented tailings backfill under blast loading.All of the parameters required for the variable-modulus viscoplastic cap model were obtained by applying the THMC model to reproducing evolution of cemented paste backfill(CPB)properties in the curing process.Thus,the behavior of hydrating cemented backfill under high-rate impacts can be evaluated under any curing time of concern.The validation results of the proposed model indicate a good agreement between the experimental and the simulated results.The authors believe that the proposed model will contribute to a better understanding of the performance of hydrating cemented backfill under blasting,and also to practical risk management of backfill structures associated with such a dynamic condition.
