Rockfill materials have been widely used in the construction of rockfill dam,railway and highway subgrade due to its high filling density,good compaction performance,strong water permeability,small settlement deformat...Rockfill materials have been widely used in the construction of rockfill dam,railway and highway subgrade due to its high filling density,good compaction performance,strong water permeability,small settlement deformation and high bearing capacity.A reasonable constitutive model for rockfill materials is very important for engineering computation and analysis,and has a great development space.Based on the crushing stress and spatial mobilized plane(SMP),a state parameter that can comprehensively reflect the anisotropy and grain crushing is proposed.This state parameter is used to improve the MPZ model(a modifed ZienkiewiczⅢmodel),so that a generalized plastic model is constructed to describe the stress and deformation characteristics of rockfill materials in engineering.The validity of the developed model is verified by a series of conventional triaxial tests with different inclination angles of the compaction plane.The variation trend of the constructed anisotropy indexωcan reflect the non monotonic variation of the deformation and strength of rockfill with the direction angle of large principal stress,so the model can reflect the obvious difference caused by the initial anisotropy of rockfill on the mechanical properties.展开更多
Particle breakage has a significant influence on the stress-strain and strength behavior of rockfill material.A breakage critical state theory(BCST)was proposed to describe the evolution of particle breakage.The break...Particle breakage has a significant influence on the stress-strain and strength behavior of rockfill material.A breakage critical state theory(BCST)was proposed to describe the evolution of particle breakage.The breakage critical state line in the breakage critical state theory was correlated with the breakage factor,which was fundamentally different from that of the original critical state theory.A simple elastoplastic constitutive model was developed for rockfill in the frame of BCST.An associated flow rule was adopted in this model.Isotropic,contractive and distortional hardening rules were suggested in view of the particle breakage.It was observed that the proposed model could well represent the complex deformation behaviors of rockfill material,such as the strain hardening,post-peak strain softening,volumetric contraction,volumetric expansion,and particle breakage under different initial confining pressures.展开更多
基金Project(2017YFC0404802)supported by the National Key R&D Program of ChinaProjects(U1965206,51979143)supported by the National Natural Science Foundation of ChinaProject([2018]5630)supported by the Talents of Guizhou Science and Technology Cooperation Platform,China。
文摘Rockfill materials have been widely used in the construction of rockfill dam,railway and highway subgrade due to its high filling density,good compaction performance,strong water permeability,small settlement deformation and high bearing capacity.A reasonable constitutive model for rockfill materials is very important for engineering computation and analysis,and has a great development space.Based on the crushing stress and spatial mobilized plane(SMP),a state parameter that can comprehensively reflect the anisotropy and grain crushing is proposed.This state parameter is used to improve the MPZ model(a modifed ZienkiewiczⅢmodel),so that a generalized plastic model is constructed to describe the stress and deformation characteristics of rockfill materials in engineering.The validity of the developed model is verified by a series of conventional triaxial tests with different inclination angles of the compaction plane.The variation trend of the constructed anisotropy indexωcan reflect the non monotonic variation of the deformation and strength of rockfill with the direction angle of large principal stress,so the model can reflect the obvious difference caused by the initial anisotropy of rockfill on the mechanical properties.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.106112015CDJXY200008)China Scholarship Council(Grant No.201306710022)
文摘Particle breakage has a significant influence on the stress-strain and strength behavior of rockfill material.A breakage critical state theory(BCST)was proposed to describe the evolution of particle breakage.The breakage critical state line in the breakage critical state theory was correlated with the breakage factor,which was fundamentally different from that of the original critical state theory.A simple elastoplastic constitutive model was developed for rockfill in the frame of BCST.An associated flow rule was adopted in this model.Isotropic,contractive and distortional hardening rules were suggested in view of the particle breakage.It was observed that the proposed model could well represent the complex deformation behaviors of rockfill material,such as the strain hardening,post-peak strain softening,volumetric contraction,volumetric expansion,and particle breakage under different initial confining pressures.
