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Active and passive anchors in loose or rocky terrain (in French)
109A with a sophisticated method requiring extensive site investigation data. High quality data will improve borability prediction, but, unless it can be obtained cheaply, cost benefit considerations will favour elementary methods. Diamond drilling rates can be predicted knowing uniaxial compressive strength of the rock. Percussion drilling rates can be predicted by means of an empirical indenter drop test. 68 refs. 873190 Effectiveness of tunnelling machines Poole, D Tunn Tunnig 1/19, NI, Jan 1987, P66-67 A summary of CIRIA research project 351, mechanical excavation of rock. The cutting efficiency of disc cutters is examined in terms of disc interaction for optimum efficiency. An alternative approach is made in terms of rock cutting specific energy, which can be related by a simple energy balance to the concept of fracture toughness. 873191 State of the art in rock fragmentation Summers, D A In: Application of Rock Characterization Techniques in Mine Design (papers to the International Symposium on Application of Rock Charaeterisation Techniques in Mine Design, New Orleans, March 1986) P163-169. Publ Littleton: AIME, 1986 The major development in rock fragmentation has been growth in the use of mechanical excavation equipment, either full face with tunnel boring machines or through the use of roadheaders. Tunnel boring machines, roadheaders, water jet cutting systems, water jet drilling, and the use of water jets to cut blast holes with non-circular geometry are discussed. 873192 Characterization of coal breakage as a function of operating parameters
Khair, A W; Reddy, N P In: Application of Rock Characterization Techniques in Mine
Design (papers to the International Symposium on Application of Rock Characterisation Techniques in Mine Design, New Orleans, March 1986) P170-180. Publ Littleton: AIME, 1986 An attempt is made to characterize coal breakage due to the action of a continuous miner. Coal blocks were subject to confining pressures equivalent to in situ conditions, then cut along the face/butt cleat direction. Fragmentation was studied as a function of machine operating parameters such as rate of advance, angle of attack, bit configuration, bit lacing (spacing and pattern) and bit speed at various equivalent in situ pressures.
Rock and Soil Reinforcement and Support 873193 Grouting and freezing for shaft water control in Milwaukee
Doig, P J Proc of the 1985 Rapid Excavation and Tunneling Conference, New York, 16-20 June 1985 V2, P1211-1224. Publ New York: AIME, 1985 The construcion of the Inline Pump Station for the Milwaukee Metropolitan Sewerage District involves the sinking of three shafts and the excavation of a pump chamber. To protect
against major inrushes of high pressure water in the rock, an extensive program of pre-grouting from the surface was specified. Freezing was chosen to control water in the sediments in each case. The grouting and freezing procedures used are described in detail.
Bolts and anchors See also: 873095, 873098, 873224
873194 Active and passive anchors in loose or rocky terrain (In French)
Descoeudres, F In: 50 Years of the Soil and Rock Mechanics Laboratories of
EPF Lausanne. Swiss Society of Soil and Rock Mechanics publication NIl2, 1986. PS-11
Anchors in rock are first considered and the selection and dimensioning of anchors for a tunnel and the use of anchors to reinforce fissured rocks beneath dam foundations are studied. The joint shear strength of reinforced rocks is briefly discussed. Secondly, anchors in cohesive soils are examined. Scale model tests being undertaken are described, and soil nailing analysed. It is concluded that anchors work in different manners in rock and soil mediums, and it is necessary to understand this to utilize them most efficiently.
873195 Generalized displacements of a rigid elliptical anchor embedded at a bi-material geological interface Selvadurai, A P S; Au, M C Int J Num Anal Meth Geomech VIO, N6, Nov-Dec 1986, P633-652 The class of problems related to a flat rigid anchoring region which is embedded at a geological interface is examined. The analysis focuses on the evaluation of the elastic stiffness of the embedded anchor. A boundary element technique is used to estimate the axial, rotational and transitional stiffnesses of the anchor. These estimates are compared with a set of bounds which are evaluated in exact closed form. These bounds are obtained by invoking kinematic and/or traction constraints at the geological interface. The numerical results presented illustrate the manner in which the various stiffnesses of the anchoring region are influenced by the elastic properties of the surrounding geological media. Auth.
873196 Soil anchors and constitutive laws Saran, S; Ranjan, G; Nene, A S J Geotech Engng Div ASCF, V112, NI2, Dec 1986, P10841100 An analysis for obtaining complete load/deformation characteristics of anchors is proposed using hyperbolic stress-strain curves of soils as the constitutive law. The analysis incorporates the effect of the shape of the anchor. Strip, square, and circular anchors are analysed. Analytical data are compared with the available experimental results, which show good agreement.
© 1987 Pergamon Journals Ltd. Reproduction not permitted
Khair, A W; Reddy, N P In: Application of Rock Characterization Techniques in Mine
Design (papers to the International Symposium on Application of Rock Characterisation Techniques in Mine Design, New Orleans, March 1986) P170-180. Publ Littleton: AIME, 1986 An attempt is made to characterize coal breakage due to the action of a continuous miner. Coal blocks were subject to confining pressures equivalent to in situ conditions, then cut along the face/butt cleat direction. Fragmentation was studied as a function of machine operating parameters such as rate of advance, angle of attack, bit configuration, bit lacing (spacing and pattern) and bit speed at various equivalent in situ pressures.
Rock and Soil Reinforcement and Support 873193 Grouting and freezing for shaft water control in Milwaukee
Doig, P J Proc of the 1985 Rapid Excavation and Tunneling Conference, New York, 16-20 June 1985 V2, P1211-1224. Publ New York: AIME, 1985 The construcion of the Inline Pump Station for the Milwaukee Metropolitan Sewerage District involves the sinking of three shafts and the excavation of a pump chamber. To protect
against major inrushes of high pressure water in the rock, an extensive program of pre-grouting from the surface was specified. Freezing was chosen to control water in the sediments in each case. The grouting and freezing procedures used are described in detail.
Bolts and anchors See also: 873095, 873098, 873224
873194 Active and passive anchors in loose or rocky terrain (In French)
Descoeudres, F In: 50 Years of the Soil and Rock Mechanics Laboratories of
EPF Lausanne. Swiss Society of Soil and Rock Mechanics publication NIl2, 1986. PS-11
Anchors in rock are first considered and the selection and dimensioning of anchors for a tunnel and the use of anchors to reinforce fissured rocks beneath dam foundations are studied. The joint shear strength of reinforced rocks is briefly discussed. Secondly, anchors in cohesive soils are examined. Scale model tests being undertaken are described, and soil nailing analysed. It is concluded that anchors work in different manners in rock and soil mediums, and it is necessary to understand this to utilize them most efficiently.
873195 Generalized displacements of a rigid elliptical anchor embedded at a bi-material geological interface Selvadurai, A P S; Au, M C Int J Num Anal Meth Geomech VIO, N6, Nov-Dec 1986, P633-652 The class of problems related to a flat rigid anchoring region which is embedded at a geological interface is examined. The analysis focuses on the evaluation of the elastic stiffness of the embedded anchor. A boundary element technique is used to estimate the axial, rotational and transitional stiffnesses of the anchor. These estimates are compared with a set of bounds which are evaluated in exact closed form. These bounds are obtained by invoking kinematic and/or traction constraints at the geological interface. The numerical results presented illustrate the manner in which the various stiffnesses of the anchoring region are influenced by the elastic properties of the surrounding geological media. Auth.
873196 Soil anchors and constitutive laws Saran, S; Ranjan, G; Nene, A S J Geotech Engng Div ASCF, V112, NI2, Dec 1986, P10841100 An analysis for obtaining complete load/deformation characteristics of anchors is proposed using hyperbolic stress-strain curves of soils as the constitutive law. The analysis incorporates the effect of the shape of the anchor. Strip, square, and circular anchors are analysed. Analytical data are compared with the available experimental results, which show good agreement.
© 1987 Pergamon Journals Ltd. Reproduction not permitted