1,721,049 research outputs found
Quick consideration for rock dowels in block theory and equilibrium analyses
No full textThis paper provides the stabilizing forces applied by rock dowels to rock blocks. These rock reinforcing elements are also known as Continuously Mechanically Coupled (CMC) rockbolts, fully grouted bolts, fully grouted rockbolts, fully-bonded rock bolts, passive anchors, passive bolts, and untensioned grouted rock bolts. The formulation is presented within Block Theory and 2-D Limit Equilibrium Analyses. The formulation takes into account the fracture dilatancy that activates a beneficial normal compressive force across the fracture intersected by the dowel, but it does not take into account the dowel-grout-rock interaction. The designer is not forced to guess parameters that, at the design stage, are simply unknown and that no one will ever test in the field. Accounting for dowel-grout-rock interaction increases the design strength of the dowel: however, a small void o defect in the grout may significantly reduce the strength and stiffness assumed in the design, and the design would be unconservative. Only the steel yield stress and the bar diameter are needed: these parameters are specified by the designer in the contract documents
Jsce-sf6 limitations for shear tests and astm d5607 shear tests on fiber-reinforced concrete
No full textAlthough several JSCE-SF6 tests have established the strength improvements caused by fiber reinforcement, it is unknown whether the measured strength improvements are caused by shear strength improvements (that is, Mode II), or by tensile or flexural strength improvement (Mode I). This paper provides a basic understanding of the state of stress: 1) in a JSCE-SF6 test; and 2) in an ASTM D5607 direct shear test, which has never been used earlier to investigate the shear strength of fiber-reinforced concrete (FRC). It was found that the JSCE-SF6 standard does not test the shear strength of a material, and it cannot be used to obtain shear characteristics of FRC. On the other hand, the ASTM D5607 standard can be used effectively to obtain shear characteristics of FRC because it creates a stress field very close to pure shear. The addition of steel fibers to concrete does not increase the peak shear strength of concrete
Analysis of single rock blocks for general failure modes under conservative and non-conservative forces
No full textSimplified Consideration for Permanent Rock Dowels in Block Theory and 2-D Limit Equilibrium Analyses
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Three-dimensional green’s functions in anisotropic piezoelectric solids
No full textExplicit expressions for three-dimensional extended Green's displacements in general anisotropic piezoelectric solids are derived. A very efficient procedure for the numerical evaluation of the derivatives of the extended Green's displacements is also proposed. Numerical comparisons are carried out for a transversely isotropic piezoelectric solid for which exact closed-form solutions are available. It is found that the extended Green's displacements and their derivatives obtained with the present explicit formulation are in perfect agreement with the exact closed-form solutions. These Green's functions can be used in the boundary integral equations for piezoelectric solids of general anisotropy and for subsequent numerical solutions of these equations by means of the boundary element method. © 1999 Elsevier Science Ltd
Closed-form and numerical solutions for the probability distribution function of fracture diameters
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On the existence, uniqueness and correctness of the fracture diameter distribution given the fracture trace length distribution
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