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Influence of the geological structure on the performance of full-face tunnelling machines in mining
63A Analysis has shown evidence to support the relationship between the cracks on the eastern section of the monastery and the landslide of the rock mass. Geological and tectonic conditions in the area are determined, as well as the cause and the geometry of the sliding rock mass. With stereographic projections, the equilibrium conditions of the whole system are analysed.
Influence of dynamic loads due to explosions or earthquakes 852201 Use of Ritz vectors in wave propagation and foundation response Bayo, E P; Wilson, E L
Eoetlu1 F,ngng Struet Dynam V12, N4, July-Aug 1984, P499505 852202 Dynamic response of dams and other structures to differential Wound motions Dumanoglu, A A; Severn, R T
Inst Civ Engr Proc V77, Sept 1984, P333-352 If an affected surface structure is large, it takes an earthquake a finite time to pass from one side of the structure to the other. This produces a pseudo-static displacement in addition to the normal dynamic displacement caused by inertia and should be taken into account. These pseudo-static displacements are time dependent and cause additional stresses. The magnitude of these stresses are considered for portal frames and 3 types of dams with earthquake propagation speeds of infinity, 4000m/s and 2000m/s. 852203 Seismic hydrodynamic forces on rock slopes Ghaboussi, J; Hendron, A J
J Geotecl~ Engng Div ASCE VllO, NGT8, Aug 1984, P10421058 A finite element method of analysis for seismic response of fluid-structure problems is presented. Displacement model finite elements are used in the fluid region, leading to simple fluid-structure interface conditions. The methodology has been used in a parametric study of seismic hydrodynamic forces on rock slope. Parameters considered in the study are: height of the slope; depth of water; slope of the rock face; and the earthquake base motion. A method for evaluation of seismically induced movements of submerged rock slope is presented. 852204 Chimney drains to control seismic pore pressures Bolognesi, A J L
J Geotech Engng Div ASCE Vl10, NGTg, Sept 1984, P13421364 To control the earthquake-induced pore pressures in earth dams with pervious gravelly shells, a method is presented to design chimney drains to be installed in the upstream submerged part of the embankment. It has been developed using the theoretical work of Seed on the determination of the pore pressure buildup in a material in which simultaneous generation and dissipation take place, the experimental work of Lee and Albalsa on the reconsolidation volume change from an induced excess pore pressure condition and Terzaghi's theory of consolidation. An example taken from an actual case is presented to explain the different steps as well as conclusions on the characteristics ofthe materials to which the proposed solution might be successfully applied. Auth.
8522O5 Plasticity models for seismic analyses of slopes Mizuno, E; Chen, W F
Soil Dynam Ewala1 Engng V3, N1, Jan 1984, P2-7 Large deformation seismic analyses of vertical slopes have been performed using the Drucker-Prager and elliptic cap models, in order to compare these models and to compare the finite element and the limit analysis methods of analysis. Development and verification of the 'pseudo-static' method of the finite element analysis after the sliding as well as before the sliding of the slopes are also studied. Emphasis is placed on the effect of large deformation of slopes on the evaluation of overall slope stability problems. 852206 Shear vibration of inhomogeneous earth dams in rectangular canyons Oner, M
Soil Dynam Eart&! Engng V3, N1, Jan 1984, P19-26 Analytical solutions for the shear vibrations of embankment dams in the upstream-downstream direction are presented, considering both inhomogeneity and three-dimensional effects. Unlike the homogeneous case, valley shape couples analytically with the inhomogeneity of the shear modulus. This coupling affects the mode shapes, frequencies and modal participation factors. 852207 Seismic response of end-bearing piles Gazetas, G
Soil Dynam Eart&! Engng V3, N2, April 1984, P82-93 The dynamic response of end-bearing piles embedded in a number of idealised soil deposits and subjected to vertically propagating harmonic S waves is presented. 'Kinematic' and 'inertial' interaction results are shown in the form of dimensionless graphs and formulae covering a wide range of excitation frequencies and of crucial material and geometric parameters. Practical aspects of the evaluation of the influence of piles on the effective seismic excitation of a structure are discussed and a case history illustrates the results. 852208 Vibration damage from blasts and tremors Green, R W E
In: Monitoring foe Safety in Geoteclmical Engineering, 10 August 1984 P89-104. Publ South Africa: South African National Group on Rock Mechanics, 1984 It is concluded from a review of the present status of vibration damage due to blasts and tremors that general damage criteria restricting ground particle velocity to a maximum of 50ram/see are too restrictive. The criteria should be determined by the specific situation.
Comminution of Rocks 852209 Influence of the geological structure on the performance of full-face tunnelling machines in mining Sanio, H P; Kutter, H K
BuadesmiMstaqmn fin" Foesclumg und Technoiogie Foeselumgsbericht T82-189, Oct 1982, 52P Cuttability and drillability of rock are similarly affected by geological structural features as are strength and deformability of a rock mass. The results of wedge penetration tests and disk cutting experiments on rocks with a distinctive strength anisotropy clearly show that anisotropy and dicontinuities have
64A to be fully taken into account for realistic predictions of the rate of penetration of a full-face tunnelling machine. A simplified procedure, assuming continuity and isotropy, would lead to wrong predictions. This is demonstrated on Ruhr sandstone, a rock of only slight strength anisotropy. There the rate of advance of a full-face tunnelling machine in a direction normal to the bedding can be 1.3 times higher than in the direction parallel to it. An important mechanical parameter for the prediction of such differences is the tensile strength of the rock, particularly its degree of anisotropy.
852210 Penetration tests on rock samples from the Carhuaquero Project, Peru (In Swedish) Smedberg, U Swedish Detonic Research Foundation report D S 1983.'13, 28 Dec 1983, 45P Results from boring with a TBM at Carhuaquero, Peru, are compared to the indentation test results of Handewith (1970). The correlation was found to be very good for the parts of the tunnel where the joint distance was large enough not to influence the penetration rate. Joint distances of 5r.10cm made the test underestimate the penetration. For agglomerate rock type, the penetration index gave an overestimation of the penetration, due to the action of discs on the harder fragments in a soft matrix. Avail: The Foundation, Box 32058, 5-12 6 11 Stockholm, Sweden
Drilling See also: 852123
852211 Improvements on blasting technique for headrace tunnels Kanoh, Y; Ohtsuka, M Proc 6th Rapid Excamfcm a d Yuueibq Coafercnce, Chicago, 12-16 June 1983 II1, P282-296. Pubi New York: AIME, 1983 In the Imaichi headrace tunnel project, long hole blasting was applied using parallel cut and smooth blasting with hydraulic drill jumbos and the NATM using robot shotcrete equipment. The results were an advance of 234.5m in a month by drilling 3.9m deep blast holes.
852212 Device for measuring drill rod and drill hole orientations Matheson, G D Transport and Road Research Laboratory report SR 817, 1984,13P Accuracy in drilling holes for explosives can be of considerable importance in the excavation of hard rock. It is particularly important in presplit blasting where final results cannot be better than the drilling allows. Traditional methods, using angled templates and spirit level, have largely been replaced by bubble and pendulum inclinometers; transducer or optical alignment gauges are also becoming common. Most however have shortcomings when precise alignment or a measurement of orientation, rather than just a setting or measure of dip, is required. The report describes a new drill orientation device which does not have these shortcomings and is simple and versatile, having an accuracy adequate for most surface excavations where precision drilling is required and a repeatability well within the requirements for presplitting. Auth. Avail: TRRL, Scottish Branch, Livingston, West Lothian
Blasting 852213 Calculation and optimization of fragmentation of rock by spherical explosive charges (In Chinese) Song Xiaotian; Weng Zhengwen Nonferrous Met V36, N3, Aug 1984, P15-20 852214 Research for improving effect of blasting in open pit (In
Chinese) Wu Zi Jun Nonferrous Met 1/36, N3, Aug 1984, P20-27 Research carried out at Dexing copper mine examined the effects of parameters on rock blasting: drilling pattern, short delay interval, specific charge, ratio of length of charge to length of stemming, ignition patterns etc. Formulae to determine reasonable blasting parameters are proposed. The research has resulted in a 23.64-32.73% reduction in specific charge and an increase of 13.14-17.6% average volume of rock excavated per metre hole at the mine.
852215 Evaluation of open-pit blast quality and its improvement approaches (In Chinese) Wu Zi-jun Q Clumgsha inst Min Res V4, N2, 1984, P32-37 Criteria for evaluating blast quality should be considered by taking into account the surrounding environment. If the blast area is far from pit slopes, surface structures and other construction, fragmentation quality of the ore rock is the major criterion. If the blast area is near the pit slope or other structures these should also be taken into account. Approaches for improving blast quality are: better classification of rock blastability and improved engineering geology work; correct selection of blast parameters; promoting the technique of controlled blasting and reduced vibration damage; developing new blast accessories; improving operation management.
852216 Controlling blast-induced cracking around large caverns Hagan, T N In: Rock Mechanics: Caverns and Pressure Shafts (paper to the I S R M Symposium, Aachen, 26-28 May 1982) V3, PI1551167. Publ Rotterdam: A. A. Balkema, 1984 Controlling overbreak and ground vibrations demands that blastholes have the optimum orientation and inclination. If a primary blast is poorly designed, there is a high probability that overbreak will occur. In strong rocks, large diameter blastholes and acceptable overbreak can be compatible, provided careful selection of the energy factor, initiation sequence and delay timing for each charge is made. Where large diameter blastholes are used in horizontal and downhole benching, presplitting of the walls of the caverns is suggested.
Cutting 852217 Lateral spacing of point-attack picks Evans, I Coal J March 1984, P7-10 852218 Rock-physical examinations in roadway drivage (In German and English) Becker, H; Lemmes, F Tunnel N2, May 1984, P71-76
Influence of dynamic loads due to explosions or earthquakes 852201 Use of Ritz vectors in wave propagation and foundation response Bayo, E P; Wilson, E L
Eoetlu1 F,ngng Struet Dynam V12, N4, July-Aug 1984, P499505 852202 Dynamic response of dams and other structures to differential Wound motions Dumanoglu, A A; Severn, R T
Inst Civ Engr Proc V77, Sept 1984, P333-352 If an affected surface structure is large, it takes an earthquake a finite time to pass from one side of the structure to the other. This produces a pseudo-static displacement in addition to the normal dynamic displacement caused by inertia and should be taken into account. These pseudo-static displacements are time dependent and cause additional stresses. The magnitude of these stresses are considered for portal frames and 3 types of dams with earthquake propagation speeds of infinity, 4000m/s and 2000m/s. 852203 Seismic hydrodynamic forces on rock slopes Ghaboussi, J; Hendron, A J
J Geotecl~ Engng Div ASCE VllO, NGT8, Aug 1984, P10421058 A finite element method of analysis for seismic response of fluid-structure problems is presented. Displacement model finite elements are used in the fluid region, leading to simple fluid-structure interface conditions. The methodology has been used in a parametric study of seismic hydrodynamic forces on rock slope. Parameters considered in the study are: height of the slope; depth of water; slope of the rock face; and the earthquake base motion. A method for evaluation of seismically induced movements of submerged rock slope is presented. 852204 Chimney drains to control seismic pore pressures Bolognesi, A J L
J Geotech Engng Div ASCE Vl10, NGTg, Sept 1984, P13421364 To control the earthquake-induced pore pressures in earth dams with pervious gravelly shells, a method is presented to design chimney drains to be installed in the upstream submerged part of the embankment. It has been developed using the theoretical work of Seed on the determination of the pore pressure buildup in a material in which simultaneous generation and dissipation take place, the experimental work of Lee and Albalsa on the reconsolidation volume change from an induced excess pore pressure condition and Terzaghi's theory of consolidation. An example taken from an actual case is presented to explain the different steps as well as conclusions on the characteristics ofthe materials to which the proposed solution might be successfully applied. Auth.
8522O5 Plasticity models for seismic analyses of slopes Mizuno, E; Chen, W F
Soil Dynam Ewala1 Engng V3, N1, Jan 1984, P2-7 Large deformation seismic analyses of vertical slopes have been performed using the Drucker-Prager and elliptic cap models, in order to compare these models and to compare the finite element and the limit analysis methods of analysis. Development and verification of the 'pseudo-static' method of the finite element analysis after the sliding as well as before the sliding of the slopes are also studied. Emphasis is placed on the effect of large deformation of slopes on the evaluation of overall slope stability problems. 852206 Shear vibration of inhomogeneous earth dams in rectangular canyons Oner, M
Soil Dynam Eart&! Engng V3, N1, Jan 1984, P19-26 Analytical solutions for the shear vibrations of embankment dams in the upstream-downstream direction are presented, considering both inhomogeneity and three-dimensional effects. Unlike the homogeneous case, valley shape couples analytically with the inhomogeneity of the shear modulus. This coupling affects the mode shapes, frequencies and modal participation factors. 852207 Seismic response of end-bearing piles Gazetas, G
Soil Dynam Eart&! Engng V3, N2, April 1984, P82-93 The dynamic response of end-bearing piles embedded in a number of idealised soil deposits and subjected to vertically propagating harmonic S waves is presented. 'Kinematic' and 'inertial' interaction results are shown in the form of dimensionless graphs and formulae covering a wide range of excitation frequencies and of crucial material and geometric parameters. Practical aspects of the evaluation of the influence of piles on the effective seismic excitation of a structure are discussed and a case history illustrates the results. 852208 Vibration damage from blasts and tremors Green, R W E
In: Monitoring foe Safety in Geoteclmical Engineering, 10 August 1984 P89-104. Publ South Africa: South African National Group on Rock Mechanics, 1984 It is concluded from a review of the present status of vibration damage due to blasts and tremors that general damage criteria restricting ground particle velocity to a maximum of 50ram/see are too restrictive. The criteria should be determined by the specific situation.
Comminution of Rocks 852209 Influence of the geological structure on the performance of full-face tunnelling machines in mining Sanio, H P; Kutter, H K
BuadesmiMstaqmn fin" Foesclumg und Technoiogie Foeselumgsbericht T82-189, Oct 1982, 52P Cuttability and drillability of rock are similarly affected by geological structural features as are strength and deformability of a rock mass. The results of wedge penetration tests and disk cutting experiments on rocks with a distinctive strength anisotropy clearly show that anisotropy and dicontinuities have
64A to be fully taken into account for realistic predictions of the rate of penetration of a full-face tunnelling machine. A simplified procedure, assuming continuity and isotropy, would lead to wrong predictions. This is demonstrated on Ruhr sandstone, a rock of only slight strength anisotropy. There the rate of advance of a full-face tunnelling machine in a direction normal to the bedding can be 1.3 times higher than in the direction parallel to it. An important mechanical parameter for the prediction of such differences is the tensile strength of the rock, particularly its degree of anisotropy.
852210 Penetration tests on rock samples from the Carhuaquero Project, Peru (In Swedish) Smedberg, U Swedish Detonic Research Foundation report D S 1983.'13, 28 Dec 1983, 45P Results from boring with a TBM at Carhuaquero, Peru, are compared to the indentation test results of Handewith (1970). The correlation was found to be very good for the parts of the tunnel where the joint distance was large enough not to influence the penetration rate. Joint distances of 5r.10cm made the test underestimate the penetration. For agglomerate rock type, the penetration index gave an overestimation of the penetration, due to the action of discs on the harder fragments in a soft matrix. Avail: The Foundation, Box 32058, 5-12 6 11 Stockholm, Sweden
Drilling See also: 852123
852211 Improvements on blasting technique for headrace tunnels Kanoh, Y; Ohtsuka, M Proc 6th Rapid Excamfcm a d Yuueibq Coafercnce, Chicago, 12-16 June 1983 II1, P282-296. Pubi New York: AIME, 1983 In the Imaichi headrace tunnel project, long hole blasting was applied using parallel cut and smooth blasting with hydraulic drill jumbos and the NATM using robot shotcrete equipment. The results were an advance of 234.5m in a month by drilling 3.9m deep blast holes.
852212 Device for measuring drill rod and drill hole orientations Matheson, G D Transport and Road Research Laboratory report SR 817, 1984,13P Accuracy in drilling holes for explosives can be of considerable importance in the excavation of hard rock. It is particularly important in presplit blasting where final results cannot be better than the drilling allows. Traditional methods, using angled templates and spirit level, have largely been replaced by bubble and pendulum inclinometers; transducer or optical alignment gauges are also becoming common. Most however have shortcomings when precise alignment or a measurement of orientation, rather than just a setting or measure of dip, is required. The report describes a new drill orientation device which does not have these shortcomings and is simple and versatile, having an accuracy adequate for most surface excavations where precision drilling is required and a repeatability well within the requirements for presplitting. Auth. Avail: TRRL, Scottish Branch, Livingston, West Lothian
Blasting 852213 Calculation and optimization of fragmentation of rock by spherical explosive charges (In Chinese) Song Xiaotian; Weng Zhengwen Nonferrous Met V36, N3, Aug 1984, P15-20 852214 Research for improving effect of blasting in open pit (In
Chinese) Wu Zi Jun Nonferrous Met 1/36, N3, Aug 1984, P20-27 Research carried out at Dexing copper mine examined the effects of parameters on rock blasting: drilling pattern, short delay interval, specific charge, ratio of length of charge to length of stemming, ignition patterns etc. Formulae to determine reasonable blasting parameters are proposed. The research has resulted in a 23.64-32.73% reduction in specific charge and an increase of 13.14-17.6% average volume of rock excavated per metre hole at the mine.
852215 Evaluation of open-pit blast quality and its improvement approaches (In Chinese) Wu Zi-jun Q Clumgsha inst Min Res V4, N2, 1984, P32-37 Criteria for evaluating blast quality should be considered by taking into account the surrounding environment. If the blast area is far from pit slopes, surface structures and other construction, fragmentation quality of the ore rock is the major criterion. If the blast area is near the pit slope or other structures these should also be taken into account. Approaches for improving blast quality are: better classification of rock blastability and improved engineering geology work; correct selection of blast parameters; promoting the technique of controlled blasting and reduced vibration damage; developing new blast accessories; improving operation management.
852216 Controlling blast-induced cracking around large caverns Hagan, T N In: Rock Mechanics: Caverns and Pressure Shafts (paper to the I S R M Symposium, Aachen, 26-28 May 1982) V3, PI1551167. Publ Rotterdam: A. A. Balkema, 1984 Controlling overbreak and ground vibrations demands that blastholes have the optimum orientation and inclination. If a primary blast is poorly designed, there is a high probability that overbreak will occur. In strong rocks, large diameter blastholes and acceptable overbreak can be compatible, provided careful selection of the energy factor, initiation sequence and delay timing for each charge is made. Where large diameter blastholes are used in horizontal and downhole benching, presplitting of the walls of the caverns is suggested.
Cutting 852217 Lateral spacing of point-attack picks Evans, I Coal J March 1984, P7-10 852218 Rock-physical examinations in roadway drivage (In German and English) Becker, H; Lemmes, F Tunnel N2, May 1984, P71-76