A large number of hydraulic concrete structures have hidden defects such as cracks, erosion, freeze and thaw, thermal fatigue, carbonization. These hidden defects seriously affect the strength, stability and durabilit...A large number of hydraulic concrete structures have hidden defects such as cracks, erosion, freeze and thaw, thermal fatigue, carbonization. These hidden defects seriously affect the strength, stability and durability of structures. These problems are studied mainly by single monitoring or diagnosis methods at present. The integration of multiple monitoring and diagnosis methods is not applied widely. Besides, the analysis theory on these problems is not developed very well. The systemic study on the aging mechanism of hydraulic concrete structures, time- variation model and health diagnosis is still not enough. The support for engineering practice is limited. Aimed at these major scientific and technological problems and combined with specific projects, study on detection of hidden defects and health diagnosis of hydraulic concrete structure has been carried out. This study includes the following content: field non-destructive examination of hidden defects of hydraulic concrete structures, seepage detection, the construction of in-situ sensing system, the combination of field detection and in-situ monitoring, the mechanism of crack, freeze and thaw, erosion and carbonization of hydraulic concrete structure, mechanism of combination aging; time-variation model of hydraulic concrete structure, theories and methods for health diagnosis of hydraulic concrete structures.展开更多
In this study, the damage-plasticity model for concrete that was verified by the model experiment was used to calculate the damage to a spiral case structure based on the damage mechanics theory. The concrete structur...In this study, the damage-plasticity model for concrete that was verified by the model experiment was used to calculate the damage to a spiral case structure based on the damage mechanics theory. The concrete structure surrounding the spiral case was simulated with a three-dimensional finite element model. Then, the distribution and evolution of the structural damage were studied. Based on investigation of the change of gap openings between the steel liner and concrete structure, the impact of the non-uniform variation of gaps on the load-beating ratio between the steel liner and concrete structure was analyzed. The comparison of calculated results of the simplified and simulation algorithms shows that the simulation algorithm is a feasible option for the calculation of spiral case structures. In addition, the shell-spring model was introduced for optimization analysis, and the results were reasonable.展开更多
基金Supported by the Key Project of Chinese National Programs for Fundamental Research and Development (Grant No. 2002CB412707) Key Project of NNSF and Yalongjiang Hydroelectric Development Joint Research Fund (50539110, 50539030)+2 种基金 Science and Technology Support Plan (20006BAC14B03) National Natural Science Foundation Major Project (50539010)National Natural Science Foundation of China (Grant No. 50579010)
文摘A large number of hydraulic concrete structures have hidden defects such as cracks, erosion, freeze and thaw, thermal fatigue, carbonization. These hidden defects seriously affect the strength, stability and durability of structures. These problems are studied mainly by single monitoring or diagnosis methods at present. The integration of multiple monitoring and diagnosis methods is not applied widely. Besides, the analysis theory on these problems is not developed very well. The systemic study on the aging mechanism of hydraulic concrete structures, time- variation model and health diagnosis is still not enough. The support for engineering practice is limited. Aimed at these major scientific and technological problems and combined with specific projects, study on detection of hidden defects and health diagnosis of hydraulic concrete structure has been carried out. This study includes the following content: field non-destructive examination of hidden defects of hydraulic concrete structures, seepage detection, the construction of in-situ sensing system, the combination of field detection and in-situ monitoring, the mechanism of crack, freeze and thaw, erosion and carbonization of hydraulic concrete structure, mechanism of combination aging; time-variation model of hydraulic concrete structure, theories and methods for health diagnosis of hydraulic concrete structures.
基金supported by the National Natural Science Foundation of China (Grant No. 51079020)the He'nan Provincial Research Foundation for Basic and Advanced Technology (Grant No. 122300410001)the Foundation of He'nan Educational Committee (Grant No. 13A570715)
文摘In this study, the damage-plasticity model for concrete that was verified by the model experiment was used to calculate the damage to a spiral case structure based on the damage mechanics theory. The concrete structure surrounding the spiral case was simulated with a three-dimensional finite element model. Then, the distribution and evolution of the structural damage were studied. Based on investigation of the change of gap openings between the steel liner and concrete structure, the impact of the non-uniform variation of gaps on the load-beating ratio between the steel liner and concrete structure was analyzed. The comparison of calculated results of the simplified and simulation algorithms shows that the simulation algorithm is a feasible option for the calculation of spiral case structures. In addition, the shell-spring model was introduced for optimization analysis, and the results were reasonable.
