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Experiences in the measurement of stresses and displacements in the Masua mine (Sardinia, Italy)
54A
Underground Excavations
have been calculated for the coal seam. The model developed can be used to predict pillar performance under different conditions of depth or pillar geometry.
Geological factors of importance in underground excavations
941430 In situ measurements and analysis for the Miios catacombs Sofianos, A J; Tsoutrelis, C E; Tzitziras, A M Proe I S R M Symposium: Eurock'92, Chester, 14-17 September 1992 P482-487. Publ London: Thomas Telford, 1992
941426 Expert system for prediction of karst disaster in excavation of tunnels or underground structures through a carbonate rock area Zhang, Q; Tian, S; Mo, Y; Dong, X; Hao, S Tunnlg Underground Space Technol 1:8, N3, July 1993, P373378 Unforeseen karst can cause disasters in tunnelling projects. An expert system for prediction of karstic features when tunnelling in carbonate rock has been developed in China. The knowledge base, knowledge representation, fuzzy pattern classification, and system operation are described.
Stresses around underground openings See also: 941197, 941200, 941244 941427 Finite element analysis of Cosserat theory for layered rock masses Dai, C; Duncan Fama, M; Meek, J; Mulhaus, H Comput Geotech V15, N3, 1993, P145-162
A layered plane has been modelled as a homogeneous plane of a Cosserat continuum using a FEM numerical approach. Applications are given for the calculation of the stress field around an excavation in such a layered medium. Emphasis is placed on the case of significant shear modulus contrast between adjacent layers. Finite element and classical analytical solutions agree for the special case of a classically elastic material. 941428 Transient response of a circular cavity in a poroelastic medium Senjuntichai, T; Rajapakse, R K N D lnt J Num Anal Metb Geomecb V17, N6, June 1993, P357383 Transient response of a pressurised long cylindrical cavity in an infnite poroelastic medium is analysed using specialised formulations of Biot's equations for poroelastodynamics. Solutions are obtained for three different types of prescribed transient radial pressures acting on permeable or impermeable cavity surfaces. Displacement, hoop stress, pore pressure, and fluid discharge are examined as functions of poroelastic material parameters. Results are compared to those of classical static and transient elastic solutions. 941429 Monitoring and simulation of sidewall fracturing in coal mines Vervoort, A Proc I S R M Symposium: Eurock'92, Chester, 14-17 September 1992 P426-431. Publ London: Thomas Telford, 1992 Behaviour of strata surrounding bord and pillar coal workings, in particular stress induced fracturing of coal pillars, has been investigated. Field measurements of extent of fracturing and in situ stress formed the basis of back analysis of the mine using the F L A C displacement discontinuity code and a MohrCoulomb material model. Cohesion values of 1.5-4.5 MPa
The Milos Island Catacombs, an important historical monument, are threatened by deterioration of the pumice-tuff rock and marginal stability of the rock mass at the crown. Stress measurements have been made at 3 potentially dangerous locations. A test adit has been driven nearby to examine underground behaviour of the rock and for testing of rehabilitation treatments. Immediate measures to strengthen the bond between grains and between joint walls and to reduce pressure loading due to surface water are necessary. Impregnation with inorganic cement grout may be such a measure. 941431 Experiences in the measurement of stresses and displacements in the Masua mine (Sardinia, Italy) Cravero, M; Iabichino, G; Dcl Greco, O Proc 3rd International Symposium on Field Measurements in Geomechanics, Oslo, 9-11 September 1991 V2. P653-662. Publ Rotterdam: A A Balkema, 1991
The Masua mine exploits two irregular sulphide orebodies in massive limestone host rock which is intersected by discontinuity sets and locally karstified. Sublevel stoping is used. Large underground openings up to 100m high and 50m wide remain, supported by pillars and rock slabs. Deformation patterns and stress changes for these structures have been monitored to ensure their stability prior to extending the mine. CSIR cells and multiple extensometer bolts have been installed. Results will be applied in design of further openings. 941432 Geomechanical and geophysical measurements in an underground marble quarry Cravero, M; Iabichino, G; Sambuelli, L Proc 3rd International Symposium on Field Measurements in Geomechanics, Osio, 9-11 September 1991 1:2, P663-671. Publ Rotterdam: A A Balkema, 1991 The Lasa quarries at Bolzano, Italy, exploit a marble lens in mica schists by room and pillar mining, currently at one level. Rooms up to 25m high and 25m wide have been excavated. To check stability of existing structures and help planning of developments at deeper levels, instrumentation stations with wire extensometers and crack meters were installed and stress measurements made in several pillars. Seismic tomography was also used to examine the integrity of some pillars. Field results for deformations and stresses are consistently greater than computed values. 941433 Calculation of stre~ and strain state around the working face in heterogeneous rock mass Veksler, Y A; Becbulatov, T A; Cbesnokov, S A Proc 7tb I S R M International Congress on Rock Mechanics, Aachen, 16-20 September 1991 1:3, P1571-1573, Publ Rotterdam: A A Balkema, 1993 Results are presented of three dimensional elastic analysis of the state of stress when a working face is driven along a coal seam of varying thickness in a heterogeneous rock mass under
Underground Excavations
have been calculated for the coal seam. The model developed can be used to predict pillar performance under different conditions of depth or pillar geometry.
Geological factors of importance in underground excavations
941430 In situ measurements and analysis for the Miios catacombs Sofianos, A J; Tsoutrelis, C E; Tzitziras, A M Proe I S R M Symposium: Eurock'92, Chester, 14-17 September 1992 P482-487. Publ London: Thomas Telford, 1992
941426 Expert system for prediction of karst disaster in excavation of tunnels or underground structures through a carbonate rock area Zhang, Q; Tian, S; Mo, Y; Dong, X; Hao, S Tunnlg Underground Space Technol 1:8, N3, July 1993, P373378 Unforeseen karst can cause disasters in tunnelling projects. An expert system for prediction of karstic features when tunnelling in carbonate rock has been developed in China. The knowledge base, knowledge representation, fuzzy pattern classification, and system operation are described.
Stresses around underground openings See also: 941197, 941200, 941244 941427 Finite element analysis of Cosserat theory for layered rock masses Dai, C; Duncan Fama, M; Meek, J; Mulhaus, H Comput Geotech V15, N3, 1993, P145-162
A layered plane has been modelled as a homogeneous plane of a Cosserat continuum using a FEM numerical approach. Applications are given for the calculation of the stress field around an excavation in such a layered medium. Emphasis is placed on the case of significant shear modulus contrast between adjacent layers. Finite element and classical analytical solutions agree for the special case of a classically elastic material. 941428 Transient response of a circular cavity in a poroelastic medium Senjuntichai, T; Rajapakse, R K N D lnt J Num Anal Metb Geomecb V17, N6, June 1993, P357383 Transient response of a pressurised long cylindrical cavity in an infnite poroelastic medium is analysed using specialised formulations of Biot's equations for poroelastodynamics. Solutions are obtained for three different types of prescribed transient radial pressures acting on permeable or impermeable cavity surfaces. Displacement, hoop stress, pore pressure, and fluid discharge are examined as functions of poroelastic material parameters. Results are compared to those of classical static and transient elastic solutions. 941429 Monitoring and simulation of sidewall fracturing in coal mines Vervoort, A Proc I S R M Symposium: Eurock'92, Chester, 14-17 September 1992 P426-431. Publ London: Thomas Telford, 1992 Behaviour of strata surrounding bord and pillar coal workings, in particular stress induced fracturing of coal pillars, has been investigated. Field measurements of extent of fracturing and in situ stress formed the basis of back analysis of the mine using the F L A C displacement discontinuity code and a MohrCoulomb material model. Cohesion values of 1.5-4.5 MPa
The Milos Island Catacombs, an important historical monument, are threatened by deterioration of the pumice-tuff rock and marginal stability of the rock mass at the crown. Stress measurements have been made at 3 potentially dangerous locations. A test adit has been driven nearby to examine underground behaviour of the rock and for testing of rehabilitation treatments. Immediate measures to strengthen the bond between grains and between joint walls and to reduce pressure loading due to surface water are necessary. Impregnation with inorganic cement grout may be such a measure. 941431 Experiences in the measurement of stresses and displacements in the Masua mine (Sardinia, Italy) Cravero, M; Iabichino, G; Dcl Greco, O Proc 3rd International Symposium on Field Measurements in Geomechanics, Oslo, 9-11 September 1991 V2. P653-662. Publ Rotterdam: A A Balkema, 1991
The Masua mine exploits two irregular sulphide orebodies in massive limestone host rock which is intersected by discontinuity sets and locally karstified. Sublevel stoping is used. Large underground openings up to 100m high and 50m wide remain, supported by pillars and rock slabs. Deformation patterns and stress changes for these structures have been monitored to ensure their stability prior to extending the mine. CSIR cells and multiple extensometer bolts have been installed. Results will be applied in design of further openings. 941432 Geomechanical and geophysical measurements in an underground marble quarry Cravero, M; Iabichino, G; Sambuelli, L Proc 3rd International Symposium on Field Measurements in Geomechanics, Osio, 9-11 September 1991 1:2, P663-671. Publ Rotterdam: A A Balkema, 1991 The Lasa quarries at Bolzano, Italy, exploit a marble lens in mica schists by room and pillar mining, currently at one level. Rooms up to 25m high and 25m wide have been excavated. To check stability of existing structures and help planning of developments at deeper levels, instrumentation stations with wire extensometers and crack meters were installed and stress measurements made in several pillars. Seismic tomography was also used to examine the integrity of some pillars. Field results for deformations and stresses are consistently greater than computed values. 941433 Calculation of stre~ and strain state around the working face in heterogeneous rock mass Veksler, Y A; Becbulatov, T A; Cbesnokov, S A Proc 7tb I S R M International Congress on Rock Mechanics, Aachen, 16-20 September 1991 1:3, P1571-1573, Publ Rotterdam: A A Balkema, 1993 Results are presented of three dimensional elastic analysis of the state of stress when a working face is driven along a coal seam of varying thickness in a heterogeneous rock mass under