Discontinuities constitute an integral part of rock mass and inherently affect its anisotropic deformation behavior.This work focuses on the equivalent elastic deformation of rock mass with multiple persistent joint s...Discontinuities constitute an integral part of rock mass and inherently affect its anisotropic deformation behavior.This work focuses on the equivalent elastic deformation of rock mass with multiple persistent joint sets.A new method based on the space geometric and mechanical properties of the modified crack tensor is proposed,providing an analytical solution for the equivalent elastic compliance tensor of rock mass.A series of experiments validate the capability of the compliance tensor to accurately represent the deformation of rock mass with multiple persistent joint sets,based on conditions set by the basic hypothesis.The spatially varying rules of the equivalent elastic parameters of rock mass with a single joint set are analyzed to reveal the universal law of the stratified rock mass.展开更多
In order to analyze the stability of the underground rock structures,knowing the sensitivity of geomechanical parameters is important.To investigate the priority of these geomechanical properties in the stability of c...In order to analyze the stability of the underground rock structures,knowing the sensitivity of geomechanical parameters is important.To investigate the priority of these geomechanical properties in the stability of cavern,a sensitivity analysis has been performed on a single cavern in various rock mass qualities according to RMR using Phase 2.The stability of cavern has been studied by investigating the side wall deformation.Results showed that most sensitive properties are coefficient of lateral stress and modulus of deformation.Also parameters of Hoek-Brown criterion and r c have no sensitivity when cavern is in a perfect elastic state.But in an elasto-plastic state,parameters of Hoek-Brown criterion and r c affect the deformability;such effect becomes more remarkable with increasing plastic area.Other parameters have different sensitivities concerning rock mass quality(RMR).Results have been used to propose the best set of parameters for study on prediction of sidewall displacement.展开更多
Deep rock mass possesses some unusual properties due to high earth stress,which further result in new problems that have not been well understood and explained up to date.In order to investigate the deformation mechan...Deep rock mass possesses some unusual properties due to high earth stress,which further result in new problems that have not been well understood and explained up to date.In order to investigate the deformation mechanism,the complete deformation process of deep rock mass,with a great emphasis on local shear deformation stage,was analyzed in detail.The quasi continuous shear deformation of the deep rock mass is described by a combination of smooth functions:the averaged distribution of the original deformation field,and the local discontinuities along the slip lines.Hence,an elasto-plastic model is established for the shear deformation process,in which the rotational displacement is taken into account as well as the translational component.Numerical analysis method was developed for case study.Deformation process of a tunnel under high earth stress was investigated for verification.展开更多
In order to imitate biological addesion performance nd skin properties,phase transitions on dielectric elastomers(D E)with high voltages are studied.The states of flat,rinkled and bulging on the circular active area w...In order to imitate biological addesion performance nd skin properties,phase transitions on dielectric elastomers(D E)with high voltages are studied.The states of flat,rinkled and bulging on the circular active area which is coated w th electrodes verify the theoretical prediction of phase transitions and failure phenomena.When the DE membrane is subjected to a radial force and increasing voltage,four experimental phenomena are discovered before electric breakdown:The active region expands,and the thin membrane is still flat till breakdown;bulging forms instead of a fa t area on the membrane;wrinkes and bulging coexist;and the active aea is completely wrinlded there are two types of phase transitions between the fa t andwrinded regions in a membrane:Wrinkles form in small regions,and te n propagate at the expense of t e flat area until he entire active part becomes wrinded;b o t the wrinded a d flat regions move interchangeably on a membrane with ramping voltage till breakdown.It is found that when Aere is no prestretch of a DE membrane,bulging w ill occur with te increasing voltage.Wrinkles commonly appear at large prestretch and,terefore,the prestetched ratio significantly affects electomechanical phase tansitions.展开更多
基金Projects(41172284,51379202) supported by the National Natural Science Foundation of ChinaProject(2013CB036405) supported by the National Basic Research Program of ChinaProject(2013BAB02B01) supported by the National Key Technologies R&D Program of China
文摘Discontinuities constitute an integral part of rock mass and inherently affect its anisotropic deformation behavior.This work focuses on the equivalent elastic deformation of rock mass with multiple persistent joint sets.A new method based on the space geometric and mechanical properties of the modified crack tensor is proposed,providing an analytical solution for the equivalent elastic compliance tensor of rock mass.A series of experiments validate the capability of the compliance tensor to accurately represent the deformation of rock mass with multiple persistent joint sets,based on conditions set by the basic hypothesis.The spatially varying rules of the equivalent elastic parameters of rock mass with a single joint set are analyzed to reveal the universal law of the stratified rock mass.
文摘In order to analyze the stability of the underground rock structures,knowing the sensitivity of geomechanical parameters is important.To investigate the priority of these geomechanical properties in the stability of cavern,a sensitivity analysis has been performed on a single cavern in various rock mass qualities according to RMR using Phase 2.The stability of cavern has been studied by investigating the side wall deformation.Results showed that most sensitive properties are coefficient of lateral stress and modulus of deformation.Also parameters of Hoek-Brown criterion and r c have no sensitivity when cavern is in a perfect elastic state.But in an elasto-plastic state,parameters of Hoek-Brown criterion and r c affect the deformability;such effect becomes more remarkable with increasing plastic area.Other parameters have different sensitivities concerning rock mass quality(RMR).Results have been used to propose the best set of parameters for study on prediction of sidewall displacement.
基金Project(50825403) supported by the National Science Fund for Distinguished Young ScholarsProject(2010CB732003) supported by the National Key Basic Research Program of ChinaProject(51021001) supported by the Science Fund for Creative Research Group of the National Natural Science Foundation of China
文摘Deep rock mass possesses some unusual properties due to high earth stress,which further result in new problems that have not been well understood and explained up to date.In order to investigate the deformation mechanism,the complete deformation process of deep rock mass,with a great emphasis on local shear deformation stage,was analyzed in detail.The quasi continuous shear deformation of the deep rock mass is described by a combination of smooth functions:the averaged distribution of the original deformation field,and the local discontinuities along the slip lines.Hence,an elasto-plastic model is established for the shear deformation process,in which the rotational displacement is taken into account as well as the translational component.Numerical analysis method was developed for case study.Deformation process of a tunnel under high earth stress was investigated for verification.
基金The National Natural Science Foundation of China No.51775108)
文摘In order to imitate biological addesion performance nd skin properties,phase transitions on dielectric elastomers(D E)with high voltages are studied.The states of flat,rinkled and bulging on the circular active area which is coated w th electrodes verify the theoretical prediction of phase transitions and failure phenomena.When the DE membrane is subjected to a radial force and increasing voltage,four experimental phenomena are discovered before electric breakdown:The active region expands,and the thin membrane is still flat till breakdown;bulging forms instead of a fa t area on the membrane;wrinkes and bulging coexist;and the active aea is completely wrinlded there are two types of phase transitions between the fa t andwrinded regions in a membrane:Wrinkles form in small regions,and te n propagate at the expense of t e flat area until he entire active part becomes wrinded;b o t the wrinded a d flat regions move interchangeably on a membrane with ramping voltage till breakdown.It is found that when Aere is no prestretch of a DE membrane,bulging w ill occur with te increasing voltage.Wrinkles commonly appear at large prestretch and,terefore,the prestetched ratio significantly affects electomechanical phase tansitions.
