Hideyuki HORII | The University of Tokyo (original) (raw)
Papers by Hideyuki HORII
Journal of Geophysical Research, 1982
Uniaxial compression of plates of brittle materials containing pre-existing planar cracks oriente... more Uniaxial compression of plates of brittle materials containing pre-existing planar cracks oriented at certain angles with respect to the direction of overall compression has revealed that the relative frictional sliding of the faces of the pre-existing cracks may produce, at their tips, tension cracks which deviate at sharp angles from the sliding plane. These tension cracks then continue to grow
Journal of Geophysical Research, 1985
Micromechanisms of rock failure (axial splitting and shear failure) are examined in light of simp... more Micromechanisms of rock failure (axial splitting and shear failure) are examined in light of simple mathematical models motivated by microscopic observations. The elasticity boundary value problem associated with cracks growing from the tips of a model flaw is solved. It is shown that under axial compression, tension cracks nucleate at the tips of the preexisting model flaw, grow with increasing compression, and become parallel to the direction of the maximum far-field compression. When a lateral compression also exists, the crack growth is stable and stops at some finite crack length. With a small lateral tension, on the other hand, the crack growth becomes unstable after a certain crack length is attained. This is considered to be the fundamental mechanism of axial splitting observed in uniaxially compressed rock specimens. To model the mechanism of shear failure, a row of suitably oriented model flaws is considered and the elasticity boundary value problem associated with the out-of-plane crack growth from the tips of the flaws is solved. It is shown that for a certain overall orientation of the flaws the growth of the out-of-plane cracks may become unstable, leading to possible macroscopic faulting. On the basis of this model the variations of the "ultimate strength" and the orientation of the overall fault plane with confining pressure are estimated, and the results are compared with published experimental data. In addition, the results of a set of model experiments on plates of Columbia resin CR39 containing preexisting flaws are reported. These experiments are specifically designed in order to show the effect of confining pressure on the crack growth regime. The experiments seem to support qualitatively the analytical results.
The accurate analysis of rock with joints is urgently needed to improve the predictions of rock b... more The accurate analysis of rock with joints is urgently needed to improve the predictions of rock behavior and to design the support of underground caverns in rock reasonably. Horii and Yoshida proposed a Micromechanics Based Continuum (MBC) model that enables to take the opening and shear slip of joints into account by replacing the rock mass containing joints with an equivalent continuum. This study applied the MBC model to a cavern excavation analysis and examined its applicability using joint and quantity of support as parameters. ' ' tan J n J s J n
Mechanical behaviors of geological material are governed by the existences and behaviors of micro... more Mechanical behaviors of geological material are governed by the existences and behaviors of microstructures such as joints or microcracks in rock mass. During cavern excavation, not only the mechanical properties but also permeability of jointed rock mass are changed due to joint deformation. In this article, the coupled modeling of deformation and flow of jointed rock mass is carried on the basis of the Micromechanics-Based Continuum approach (MBC approach). The derived model is implemented into the MBC analysis, which enables us to carry the excavation analysis of a cavern and obtain the distribution of displacement, stress, strain and permeability of rock mass and the deformation of joints.
Doboku Gakkai Ronbunshuu F, 2009
International Journal of Rock Mechanics and Mining Sciences, 2004
An analysis method that can grasp the behavior of a rock mass is necessary to establish a rationa... more An analysis method that can grasp the behavior of a rock mass is necessary to establish a rational method for designing and constructing large-scale caverns. In underground excavation, sliding and opening of joints due to stress relaxation are considered to be the governing mechanisms of the behavior of a jointed rock mass. In the present study, a micromechanics-based continuum model of a jointed rock mass is proposed and an analysis method for underground excavation is developed. To examine the performance of the proposed method, the excavation of Shiobara power station cavern constructed by the Tokyo Electric Power Co., Ltd. is analyzed and results are compared to measured data. In numerical results, for instance, displacement of the measurement facilities during excavation are in good agreement with measured data. r
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1997
The governing mechanism of behaviors of rock mass during excavation of a large scale cavern is fo... more The governing mechanism of behaviors of rock mass during excavation of a large scale cavern is found to be sliding and opening of joints initially closed by earth pressure. A constitutive model of jointed rock mass is proposed applying MBC (micromechanics-based continuum) approach. The model reflects the behaviors of joints in the analysis of a large-scale cavern. The problem of excavation of a large-scale underground power station cavern constructed by Tokyo Electricity Power Company in Japan is analyzed, and numerical results are compared with measurement data. derived from a relationship between average stress and average strain over a representative volume element (R.V.E) which contains a lot of microstructures. This theory is suitable for the analysis of rock mass containing a number of joints.
The accurate analysis of rock with joints is urgently needed to improve the predictions of rock b... more The accurate analysis of rock with joints is urgently needed to improve the predictions of rock behavior and to design the support of underground caverns in rock reasonably. Horii and Yoshida proposed a Micromechanics Based Continuum (MBC) model that enables to take the opening and shear slip of joints into account by replacing the rock mass containing joints with an equivalent continuum. This study applied the MBC model to a cavern excavation analysis and examined its applicability to the design of cavern support.
Journal of Engineering Materials and Technology-transactions of The Asme, 1994
Little research has been done on how designers actually design. Much of design research is concer... more Little research has been done on how designers actually design. Much of design research is concerned with computer based models or is based on anecdotal evidence of the design process. This paper describes the development and application of a methodology that uses protocol studies of designers engaged in design to investigate the process of designing. A coding scheme is developed and applied to design protocols. The scheme brings structure to the unstructured data of the protocols without detracting from the richness of the data. Results are shown that illustrate the utility of this approach in gaining some insight into how designers design.
Journal of Geophysical Research, 1982
Uniaxial compression of plates of brittle materials containing pre-existing planar cracks oriente... more Uniaxial compression of plates of brittle materials containing pre-existing planar cracks oriented at certain angles with respect to the direction of overall compression has revealed that the relative frictional sliding of the faces of the pre-existing cracks may produce, at their tips, tension cracks which deviate at sharp angles from the sliding plane. These tension cracks then continue to grow
Journal of Geophysical Research, 1985
Micromechanisms of rock failure (axial splitting and shear failure) are examined in light of simp... more Micromechanisms of rock failure (axial splitting and shear failure) are examined in light of simple mathematical models motivated by microscopic observations. The elasticity boundary value problem associated with cracks growing from the tips of a model flaw is solved. It is shown that under axial compression, tension cracks nucleate at the tips of the preexisting model flaw, grow with increasing compression, and become parallel to the direction of the maximum far-field compression. When a lateral compression also exists, the crack growth is stable and stops at some finite crack length. With a small lateral tension, on the other hand, the crack growth becomes unstable after a certain crack length is attained. This is considered to be the fundamental mechanism of axial splitting observed in uniaxially compressed rock specimens. To model the mechanism of shear failure, a row of suitably oriented model flaws is considered and the elasticity boundary value problem associated with the out-of-plane crack growth from the tips of the flaws is solved. It is shown that for a certain overall orientation of the flaws the growth of the out-of-plane cracks may become unstable, leading to possible macroscopic faulting. On the basis of this model the variations of the "ultimate strength" and the orientation of the overall fault plane with confining pressure are estimated, and the results are compared with published experimental data. In addition, the results of a set of model experiments on plates of Columbia resin CR39 containing preexisting flaws are reported. These experiments are specifically designed in order to show the effect of confining pressure on the crack growth regime. The experiments seem to support qualitatively the analytical results.
The accurate analysis of rock with joints is urgently needed to improve the predictions of rock b... more The accurate analysis of rock with joints is urgently needed to improve the predictions of rock behavior and to design the support of underground caverns in rock reasonably. Horii and Yoshida proposed a Micromechanics Based Continuum (MBC) model that enables to take the opening and shear slip of joints into account by replacing the rock mass containing joints with an equivalent continuum. This study applied the MBC model to a cavern excavation analysis and examined its applicability using joint and quantity of support as parameters. ' ' tan J n J s J n
Mechanical behaviors of geological material are governed by the existences and behaviors of micro... more Mechanical behaviors of geological material are governed by the existences and behaviors of microstructures such as joints or microcracks in rock mass. During cavern excavation, not only the mechanical properties but also permeability of jointed rock mass are changed due to joint deformation. In this article, the coupled modeling of deformation and flow of jointed rock mass is carried on the basis of the Micromechanics-Based Continuum approach (MBC approach). The derived model is implemented into the MBC analysis, which enables us to carry the excavation analysis of a cavern and obtain the distribution of displacement, stress, strain and permeability of rock mass and the deformation of joints.
Doboku Gakkai Ronbunshuu F, 2009
International Journal of Rock Mechanics and Mining Sciences, 2004
An analysis method that can grasp the behavior of a rock mass is necessary to establish a rationa... more An analysis method that can grasp the behavior of a rock mass is necessary to establish a rational method for designing and constructing large-scale caverns. In underground excavation, sliding and opening of joints due to stress relaxation are considered to be the governing mechanisms of the behavior of a jointed rock mass. In the present study, a micromechanics-based continuum model of a jointed rock mass is proposed and an analysis method for underground excavation is developed. To examine the performance of the proposed method, the excavation of Shiobara power station cavern constructed by the Tokyo Electric Power Co., Ltd. is analyzed and results are compared to measured data. In numerical results, for instance, displacement of the measurement facilities during excavation are in good agreement with measured data. r
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1997
The governing mechanism of behaviors of rock mass during excavation of a large scale cavern is fo... more The governing mechanism of behaviors of rock mass during excavation of a large scale cavern is found to be sliding and opening of joints initially closed by earth pressure. A constitutive model of jointed rock mass is proposed applying MBC (micromechanics-based continuum) approach. The model reflects the behaviors of joints in the analysis of a large-scale cavern. The problem of excavation of a large-scale underground power station cavern constructed by Tokyo Electricity Power Company in Japan is analyzed, and numerical results are compared with measurement data. derived from a relationship between average stress and average strain over a representative volume element (R.V.E) which contains a lot of microstructures. This theory is suitable for the analysis of rock mass containing a number of joints.
The accurate analysis of rock with joints is urgently needed to improve the predictions of rock b... more The accurate analysis of rock with joints is urgently needed to improve the predictions of rock behavior and to design the support of underground caverns in rock reasonably. Horii and Yoshida proposed a Micromechanics Based Continuum (MBC) model that enables to take the opening and shear slip of joints into account by replacing the rock mass containing joints with an equivalent continuum. This study applied the MBC model to a cavern excavation analysis and examined its applicability to the design of cavern support.
Journal of Engineering Materials and Technology-transactions of The Asme, 1994
Little research has been done on how designers actually design. Much of design research is concer... more Little research has been done on how designers actually design. Much of design research is concerned with computer based models or is based on anecdotal evidence of the design process. This paper describes the development and application of a methodology that uses protocol studies of designers engaged in design to investigate the process of designing. A coding scheme is developed and applied to design protocols. The scheme brings structure to the unstructured data of the protocols without detracting from the richness of the data. Results are shown that illustrate the utility of this approach in gaining some insight into how designers design.