- Email: [email protected]
The Gauss function and the phenomena of rock mass subsidence and displacements of granular media
ANALYSIS TECHNIQUES:STRESS existing models predicting small-strain shear moduli in clay deposits. -from Authors
ANALYSIS TECHNIQUES AND DESIGN METHODS Rock block analysis 945136 Stereologieal sampling of rock masses for engineering purposes S. M.
Miller, B. D.
Martin & J. K.
Owens, in:
Hydrogeology, waste disposal, science and politics. Prec. 30th symposium on engineering geology and geotechnical engineering, Idaho, 1994, ed P.K. Link, (Idaho State University), 1994, pp 385-393. Stereological analysis of observations made in drill holes or along the walls of underground excavations can provide two- and three-dimensional measures that help characterize discontinuous rock masses for engineering and hydrogeologic purposes. The approach is based on sampling methods developed previously in stereology for the analysis of microstructures in the fields of biology and materials science. Input information for a stereological analysis of a rock mass is best obtained by scanning (imaging) the walls of clean drill holes using a borescope or other video device. Two classes of features are investigated: I) lithologic types that comprise the overall rock mass, and 2) structural discontinuities within a given lithelogic unit. Example samplings and computations are presented for several situations based on drill holes associated with underground mining activity. Extensions of the methodology are proposed for larger diameter borings or tunnels and for exposed rock faces. -from Authors 945137 The Gauss function and the phenomena of rock mass subsidence and displacements of g r a n u l a r media J. Litwiniszyn, International Journal of Rock Mechanics & Mining Sciences, 31(2), 1994, pp 143-148. To describe the movements of a rock mass caused by underground mining exploitation there were introduced, among others, the integral formulae with the so-called influence functions as well as the probabilistic methods. In the formulae resulting from these assumptions and showing good agreement with reality, the Gauss function plays an essential role. A brief outline of the development of the ideal related to the introduction of this function is given -from Author 945138 Intersection probabilities of impersistent joints M. Mauldon, International Journal of Rock Mechanics & Mining Sciences, 31(2), 1994, pp 107-115. Joint intersection points are of interest because of their relations to the blocks that comprise the rock mass. A solution is obtained giving relative probabilities of intersection of sets of parallel, impersistent joints in a discontinuous rock mass. A solution is also found for intersection probabilities of line segments in the plane. These probabilities are shown to depend on the joint intensities and on the relative orientations of joint sets or line sets. Methods for the estimation of joint intensity by area sampling and line sampling techniques are discussed. -from Author 945139 A 3-D constitutive model for rock joints with anlsotropic friction and stress dependency in shear stiffness L. Jing, E. Nordlund & O. Stephansson, International Journal of Rock Mechanics & Mining Sciences, 31(2), 1994, pp 173-178. A 3-D constitutive model for rock joints is developed. The joint model is based on experimental results from a systematic laboratory investigation on anisotropy and stressdependency of the shear strength and shear deformability of rough joints. In the experiment, concrete replicas from two natural joint samples were sheared under different norreal stresses and in different shear directions in the plane of the joint surface. The test results demonstrated that both
241A
the shear strength and the shear stiffness of rough joints are generally anisotropic and dependent on the normal stress. -from Authors
Stress analysis 945140 On the imaging of stress changes in particulate media: an experimental study J. C. Santamarina & B. Potts, Canadian Geotechnical Journal, 31(2), 1994, pp 215-222. The stiffness of soils depends on the state of stress. Therefore, the velocity of wave propagation can be used to assess the state of stress and its changes. Indeed, given sufficient data, measurements can be inverted to produce a tomographic image of the stress field. A preliminary study of this approach was conducted with simulated data and is summarized briefly. Results of an experimental study are then presented. Three common geotechnical systems were tested: a footing, a moving surface load, and a retaining wall. -from Authors 945141 Dynamic stress intensity factor for subsurface inclined cracks Chien-Ching Ma & Szu-Kuzi Chen, Journal of Engineering Mechanics - ASCE, 120(3), 1994, pp 483-498. To gain insight into the phenomenon of the interaction of stress waves with material defect, the transient problem of a half-space containing a subsurface inclined semi-infinite crack subjected to dynamic antiplane loading on the boundary of the half-space is investigated in this study. The solutions are determined by superposition of the fundamental solution in the Laplace transform domain. The fundamental solution is the exponentially distributed traction on crack faces. The exact close form transient solutions of dynamic stress intensity factor are expressed explicitly in time domain. These solutions are valid for an infinite length of time and have accounted for the contributions coming from incident, reflected and diffracted waves. Numerical results of dynamic stress intensity factors are obtained and compared with the corresponding static values. The transient solution is shown to approach the static value after the first few waves interactive with the crack tip have passed. -Author 945142 Rock mass stress and hydrological characterisation using borehole double-packers J. Adams, K. Evans & E. Wyss, International Water Power & Dam Construction, 46(6), 1994, pp 38-44. Examples where rock stress information can lead to economies in construction costs include the design of powerhouse caverns and tunnel linings, and the prevention of excessive leaks from pressure tunnels. In the design of powerhouse caverns, information of the orientation and magnitudes of the principal rock stresses is needed to identify the strucmr~.lly-optimal excavation geometry. This article reviews the application of borehole double-packer testing techniques for characterising rock mass permeability and stress m geotechnical situations, such as stress testing in fractured rock. -S.E.Brown 945143 An analytical/numerical approach for cracked elastic strips under concentrated loads - transient response H. G. Georgiadis & N. Charalambakis, International Journal of Fracture, 65(I), 1994, pp 49-61. An analytical/numerical approach is presented for the determination of the near-up stress field arising from the scattering of SH waves by a long crack in a strip-like elastic body. The problem has two characteristic lengths, i.e. the strip width, and the distance between the point of application of concentrated forces and the crack tip. It is wellknown that the second characteristic length introduces a serious difficulty in the mathematical analysis of the problem. In particular, a non-standard Wiener-Hopf (W-H) equation arises, that contains a forcing term with unbounded behaviour at infinity in the transform plane. In addition, the presence of the strip s finite width results in a complicated W-H kernel introducing, therefore, further difficulties. This method is, however, based on integral transform analysis, an exact kemal faetorization, usage of
ANALYSIS TECHNIQUES AND DESIGN METHODS Rock block analysis 945136 Stereologieal sampling of rock masses for engineering purposes S. M.
Miller, B. D.
Martin & J. K.
Owens, in:
Hydrogeology, waste disposal, science and politics. Prec. 30th symposium on engineering geology and geotechnical engineering, Idaho, 1994, ed P.K. Link, (Idaho State University), 1994, pp 385-393. Stereological analysis of observations made in drill holes or along the walls of underground excavations can provide two- and three-dimensional measures that help characterize discontinuous rock masses for engineering and hydrogeologic purposes. The approach is based on sampling methods developed previously in stereology for the analysis of microstructures in the fields of biology and materials science. Input information for a stereological analysis of a rock mass is best obtained by scanning (imaging) the walls of clean drill holes using a borescope or other video device. Two classes of features are investigated: I) lithologic types that comprise the overall rock mass, and 2) structural discontinuities within a given lithelogic unit. Example samplings and computations are presented for several situations based on drill holes associated with underground mining activity. Extensions of the methodology are proposed for larger diameter borings or tunnels and for exposed rock faces. -from Authors 945137 The Gauss function and the phenomena of rock mass subsidence and displacements of g r a n u l a r media J. Litwiniszyn, International Journal of Rock Mechanics & Mining Sciences, 31(2), 1994, pp 143-148. To describe the movements of a rock mass caused by underground mining exploitation there were introduced, among others, the integral formulae with the so-called influence functions as well as the probabilistic methods. In the formulae resulting from these assumptions and showing good agreement with reality, the Gauss function plays an essential role. A brief outline of the development of the ideal related to the introduction of this function is given -from Author 945138 Intersection probabilities of impersistent joints M. Mauldon, International Journal of Rock Mechanics & Mining Sciences, 31(2), 1994, pp 107-115. Joint intersection points are of interest because of their relations to the blocks that comprise the rock mass. A solution is obtained giving relative probabilities of intersection of sets of parallel, impersistent joints in a discontinuous rock mass. A solution is also found for intersection probabilities of line segments in the plane. These probabilities are shown to depend on the joint intensities and on the relative orientations of joint sets or line sets. Methods for the estimation of joint intensity by area sampling and line sampling techniques are discussed. -from Author 945139 A 3-D constitutive model for rock joints with anlsotropic friction and stress dependency in shear stiffness L. Jing, E. Nordlund & O. Stephansson, International Journal of Rock Mechanics & Mining Sciences, 31(2), 1994, pp 173-178. A 3-D constitutive model for rock joints is developed. The joint model is based on experimental results from a systematic laboratory investigation on anisotropy and stressdependency of the shear strength and shear deformability of rough joints. In the experiment, concrete replicas from two natural joint samples were sheared under different norreal stresses and in different shear directions in the plane of the joint surface. The test results demonstrated that both
241A
the shear strength and the shear stiffness of rough joints are generally anisotropic and dependent on the normal stress. -from Authors
Stress analysis 945140 On the imaging of stress changes in particulate media: an experimental study J. C. Santamarina & B. Potts, Canadian Geotechnical Journal, 31(2), 1994, pp 215-222. The stiffness of soils depends on the state of stress. Therefore, the velocity of wave propagation can be used to assess the state of stress and its changes. Indeed, given sufficient data, measurements can be inverted to produce a tomographic image of the stress field. A preliminary study of this approach was conducted with simulated data and is summarized briefly. Results of an experimental study are then presented. Three common geotechnical systems were tested: a footing, a moving surface load, and a retaining wall. -from Authors 945141 Dynamic stress intensity factor for subsurface inclined cracks Chien-Ching Ma & Szu-Kuzi Chen, Journal of Engineering Mechanics - ASCE, 120(3), 1994, pp 483-498. To gain insight into the phenomenon of the interaction of stress waves with material defect, the transient problem of a half-space containing a subsurface inclined semi-infinite crack subjected to dynamic antiplane loading on the boundary of the half-space is investigated in this study. The solutions are determined by superposition of the fundamental solution in the Laplace transform domain. The fundamental solution is the exponentially distributed traction on crack faces. The exact close form transient solutions of dynamic stress intensity factor are expressed explicitly in time domain. These solutions are valid for an infinite length of time and have accounted for the contributions coming from incident, reflected and diffracted waves. Numerical results of dynamic stress intensity factors are obtained and compared with the corresponding static values. The transient solution is shown to approach the static value after the first few waves interactive with the crack tip have passed. -Author 945142 Rock mass stress and hydrological characterisation using borehole double-packers J. Adams, K. Evans & E. Wyss, International Water Power & Dam Construction, 46(6), 1994, pp 38-44. Examples where rock stress information can lead to economies in construction costs include the design of powerhouse caverns and tunnel linings, and the prevention of excessive leaks from pressure tunnels. In the design of powerhouse caverns, information of the orientation and magnitudes of the principal rock stresses is needed to identify the strucmr~.lly-optimal excavation geometry. This article reviews the application of borehole double-packer testing techniques for characterising rock mass permeability and stress m geotechnical situations, such as stress testing in fractured rock. -S.E.Brown 945143 An analytical/numerical approach for cracked elastic strips under concentrated loads - transient response H. G. Georgiadis & N. Charalambakis, International Journal of Fracture, 65(I), 1994, pp 49-61. An analytical/numerical approach is presented for the determination of the near-up stress field arising from the scattering of SH waves by a long crack in a strip-like elastic body. The problem has two characteristic lengths, i.e. the strip width, and the distance between the point of application of concentrated forces and the crack tip. It is wellknown that the second characteristic length introduces a serious difficulty in the mathematical analysis of the problem. In particular, a non-standard Wiener-Hopf (W-H) equation arises, that contains a forcing term with unbounded behaviour at infinity in the transform plane. In addition, the presence of the strip s finite width results in a complicated W-H kernel introducing, therefore, further difficulties. This method is, however, based on integral transform analysis, an exact kemal faetorization, usage of