The application of the non-explosive expansion material （NEEM） is widely used as the controlled fracture method in quarry min- ing, especially in hard rocks. The pressure of NEEM is an important parameter in causing...The application of the non-explosive expansion material （NEEM） is widely used as the controlled fracture method in quarry min- ing, especially in hard rocks. The pressure of NEEM is an important parameter in causing rock fracture. An empirical model based on hole spacing was developed to determine the pressure of NEEM in the rock fracture process. Primarily, the empirical model was developed by the mathematical method, utilizing dimensional analysis. Then, the Phase2 code, which is based on the finite element method, was utilized to predict crack growth in rocks. The results of numerical analysis show slight deviations from the empirical model. Hence, the polynomial re- gression analysis was used to modify the model. Finally, the modified model shows a good agreement with the results gained from numerical modeling.展开更多
This study aims to reveal the macroscopic permanent deformation(PD)behavior and the internal structural evolution of construction and demolition waste(CDW)under loading.Firstly,the initial matric suction of CDW was me...This study aims to reveal the macroscopic permanent deformation(PD)behavior and the internal structural evolution of construction and demolition waste(CDW)under loading.Firstly,the initial matric suction of CDW was measured by the filter paper method.Secondly,the PD of CDW with different humidity and stress states was investigated by repeated load triaxial tests,and a comprehensive prediction model was established.Finally,the discrete element method was performed to analyze the internal structural evolution of CDW during deformation.These results showed that the VAN-GENUCHTEN model could describe the soil-water characteristic curve of CDW well.The PD increases with the increase of the deviator stress and the number of cyclic loading,but the opposite trend was observed when the initial matric suction and confining pressure increased.The proposed model in this study provides a satisfactory prediction of PD.The discrete element method could accurately simulate the macroscopic PD of CDW,and the shear force,interlock force and sliding content increase with the increase of deviator stress during the deformation.The research could provide useful reference for the deformation stability analysis of CDW under cyclic loading.展开更多
The applications of numerical simulation in demolition blasting were reviewed.Several methods of numerical simulation in demolition blasting were introduced.The strength and weakness of the numerical methods mentioned...The applications of numerical simulation in demolition blasting were reviewed.Several methods of numerical simulation in demolition blasting were introduced.The strength and weakness of the numerical methods mentioned in this paper were also indicated,respectively.Furthermore,the solid lattice model in the frame of discrete element method(DEM),which was developed by the author and his team,was detailedly described.The existed problems in the current numerical simulation methods of demolition blasting were presented and the future trend of the numerical simulation is finally prospected.展开更多
文摘The application of the non-explosive expansion material （NEEM） is widely used as the controlled fracture method in quarry min- ing, especially in hard rocks. The pressure of NEEM is an important parameter in causing rock fracture. An empirical model based on hole spacing was developed to determine the pressure of NEEM in the rock fracture process. Primarily, the empirical model was developed by the mathematical method, utilizing dimensional analysis. Then, the Phase2 code, which is based on the finite element method, was utilized to predict crack growth in rocks. The results of numerical analysis show slight deviations from the empirical model. Hence, the polynomial re- gression analysis was used to modify the model. Finally, the modified model shows a good agreement with the results gained from numerical modeling.
基金Project(52025085)supported by the National Science Fund for Distinguished Young Scholars,ChinaProjects(51927814,51878078)supported by the National Natural Science Foundation of China+3 种基金Project(2018-025)supported by the Training Program for High-level Technical Personnel in Transportation Industry,ChinaProject(CTKY-PTRC 2018-003)supported by the Design Theory,Method and Demonstration of Durability Asphalt Pavement Based on Heavy-duty Traffic Conditions in Shanghai Area,ChinaProject(2020RC4048)supported by the Science and Technology Innovation Program of Hunan Province,ChinaProject(SJCX202001)supported by the Construction Project for Graduate Students of Changsha University of Science&Technology,China。
文摘This study aims to reveal the macroscopic permanent deformation(PD)behavior and the internal structural evolution of construction and demolition waste(CDW)under loading.Firstly,the initial matric suction of CDW was measured by the filter paper method.Secondly,the PD of CDW with different humidity and stress states was investigated by repeated load triaxial tests,and a comprehensive prediction model was established.Finally,the discrete element method was performed to analyze the internal structural evolution of CDW during deformation.These results showed that the VAN-GENUCHTEN model could describe the soil-water characteristic curve of CDW well.The PD increases with the increase of the deviator stress and the number of cyclic loading,but the opposite trend was observed when the initial matric suction and confining pressure increased.The proposed model in this study provides a satisfactory prediction of PD.The discrete element method could accurately simulate the macroscopic PD of CDW,and the shear force,interlock force and sliding content increase with the increase of deviator stress during the deformation.The research could provide useful reference for the deformation stability analysis of CDW under cyclic loading.
文摘The applications of numerical simulation in demolition blasting were reviewed.Several methods of numerical simulation in demolition blasting were introduced.The strength and weakness of the numerical methods mentioned in this paper were also indicated,respectively.Furthermore,the solid lattice model in the frame of discrete element method(DEM),which was developed by the author and his team,was detailedly described.The existed problems in the current numerical simulation methods of demolition blasting were presented and the future trend of the numerical simulation is finally prospected.
