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Analytical estimation of tunnel deformation based on field measurements
314A 9O548O Supervision of a tunnel using FEM back-analysis based on field measurements Fujino, K; Suzuki, K Proc 2nd lntermttional Symposinm on Field Measurements in Geomechanics, Kobe, 6-9 April 1987 V2, P1197-1206. Publ Rotterdam." A A Balkema, 1988
9O5484 Assessment of the stability, of the ground surrounding a shallow tunnel by means of back analysis method of measured displacements Sakaguchi. K; Kondoh, T: Okabe. Y: Shinji. M Proc 2nd International Symposium on Field Measurements in Geomechanics, Kobe, 6-9 April 1987 I"2. P1237-1245. Publ Rotterdam: A ,4 Balkema, 1988
Back analysis during the construction of the headrace tunnel for the Kumaushi hydroelectric project is described. NATM was used. The geology is divided into 3 sections: gravel/silt, welded tuff, and sand/gravel/silt. Shotcrete is the effective support under these conditions. The finite element program NATMFEM was used to assess support requirements based on measured deformations. Parametric studies have shown that initial values of deformation modulus and horizontal ground pressure are the dominant factors affecting deformation of the tunnel.
Experiences during the construction of the Shin-Ushizu tunnel in Japan are presented. In one region of shallow overburden and weak rock it was necessary to minimise settlement. Two side pilot tunnels were excavated, temporary side walls constructed, and the upper section exeavated using steel ribs and shotcrete support with bolts and forepoling. Finite element back analysis using the program DBAP/M (Direct Back Analysis Procedure for Microcomputers) was used to design support to limit settlement to 10mm.
905481 Analytical estimation of tunnel deformation based on field meL~urements Kunimi, H; Takasaki, H Proc 2nd International Symposium on Field Measurements in Geomechanics, Kobe, 6-9 April 1987 I/2, P1207-1216. Publ Rotterdam." A A Balkema, 1988
905485 Stability assessment of the ground around a shallow tunnel Kimura, K Proc 2nd lnternatiomd Symposium on Field Measurements in Geomedumics, Kobe, 6-9 April 1987 V2. P1247-1256. Publ Rotterdam." A A Balkema. 1988
Back analysis in NATM projects is discussed. Modelling of the interaction between the structure (shotcrete, bolts) and the ground, setting of input parameters for the finite element analysis, and determination of the deformation modulus of the ground and lateral pressure are examined. The structure of the analytical method is considered. This observational approach may also be used in the design stage, using input constants from previous experiences.
Shallow NATM tunnelling in diluvial sands in Japan is described. Settlement behaviour and possible shear failure mechanisms are first considered. Three indexes (shear index, simple shear strain, maximum surface settlement) for assessing stability on the basis of surface or subsurface settlement monitoring are presented. Field experiences with the Kuriyama tunnel are used to illustrate the procedure.
905482 Assessment of tunnel face stability by back analysis Hisatake, M Proc 2nd International Symposium on Field Measurements in Geomechanics, Kobe, 6-9 April 1987 II2, P1217-1224. Publ Rotterdam: A A Balkema, 1988
905486 Slot-drilling and splitting method for tunnel driving Hagimori, K; Watanabe, H; Nakagawa, K; Furakawa, K Proc MMIJ/ IMM Joint Symposium, Today's Technology for the Mining and Metallurgical Industries, Kyoto, 2-4 October 1989 P155-160. Publ London." MMIJ/IMM, 1989
A 3-dimensional finite element back analysis approach to the determination of stability at the tunnel face is presented. Mechanical properties and excavation stresses released at the face must be determined beforehand. The validity of the procedure is demonstrated by comparing maximum shear stress in the lining caused by excavation using the SA (Sequence Analysis) method with real and back analysed input data.
Construction of tunnels by blasting in urban areas or areas close to existing structures tends to cause problems due to vibrations, and low vibration or non-blasting tunnelling methods are becoming esential. Slot-drilling and splitting techniques have been developed for these purposes. Characteristics of these methods and their applications for low vibration tunnelling are discussed with reference to a tunnel in compentent granitic rock.
905483 Technique of field ~ m e n t interpretation in erecting underground openings of round section Bulychev, N S; Savin, I I Proc 2rid imertmtiomd Symposium on Field Measurements in Geomechanics, Kobe, 6-9 April 1987 I/2, P1225-1230. Pub/ Rotterdam: A A Balkema, 1988
905487 Watertight lining systems to secure leaking shafts Valk, J Proc Conference on Shaft Emgineeriog, Harrogate, 5-7 June 1989 P353-363. Publ London: IMM, 1989
A method for the design of multilayer linings for deep, circular tunnels is presented. It is based on analysis of stresses and deformations measured at an arbitrary contact of a monolayer lining or upon a contact of the lining with the rock mass. The initial stress state and effects of time lag in erecting the lining are evaluated without dependence on the geometry or materials properties of the lining in which the measurements are made, and thus may be used in the design of other linings for similar conditions.
The development and design of new lining systems to secure older leaking or unstable shafts are described. Three systems were developed: (1) reinforced concrete cylinder with outer welded steel liner and asphalt layer; (2)jointless reinforced concrete cylinder with asphalt layer; and (3) fully welded steel liner with concrete backfill and chemical seal ring. Two case studies are presented to illustrate planning and design, choice of lining system, structural design and execution of work using systems (2) and (3).
© 1990 Pergamon Press plc. Reproduction not permitted
9O5484 Assessment of the stability, of the ground surrounding a shallow tunnel by means of back analysis method of measured displacements Sakaguchi. K; Kondoh, T: Okabe. Y: Shinji. M Proc 2nd International Symposium on Field Measurements in Geomechanics, Kobe, 6-9 April 1987 I"2. P1237-1245. Publ Rotterdam: A ,4 Balkema, 1988
Back analysis during the construction of the headrace tunnel for the Kumaushi hydroelectric project is described. NATM was used. The geology is divided into 3 sections: gravel/silt, welded tuff, and sand/gravel/silt. Shotcrete is the effective support under these conditions. The finite element program NATMFEM was used to assess support requirements based on measured deformations. Parametric studies have shown that initial values of deformation modulus and horizontal ground pressure are the dominant factors affecting deformation of the tunnel.
Experiences during the construction of the Shin-Ushizu tunnel in Japan are presented. In one region of shallow overburden and weak rock it was necessary to minimise settlement. Two side pilot tunnels were excavated, temporary side walls constructed, and the upper section exeavated using steel ribs and shotcrete support with bolts and forepoling. Finite element back analysis using the program DBAP/M (Direct Back Analysis Procedure for Microcomputers) was used to design support to limit settlement to 10mm.
905481 Analytical estimation of tunnel deformation based on field meL~urements Kunimi, H; Takasaki, H Proc 2nd International Symposium on Field Measurements in Geomechanics, Kobe, 6-9 April 1987 I/2, P1207-1216. Publ Rotterdam." A A Balkema, 1988
905485 Stability assessment of the ground around a shallow tunnel Kimura, K Proc 2nd lnternatiomd Symposium on Field Measurements in Geomedumics, Kobe, 6-9 April 1987 V2. P1247-1256. Publ Rotterdam." A A Balkema. 1988
Back analysis in NATM projects is discussed. Modelling of the interaction between the structure (shotcrete, bolts) and the ground, setting of input parameters for the finite element analysis, and determination of the deformation modulus of the ground and lateral pressure are examined. The structure of the analytical method is considered. This observational approach may also be used in the design stage, using input constants from previous experiences.
Shallow NATM tunnelling in diluvial sands in Japan is described. Settlement behaviour and possible shear failure mechanisms are first considered. Three indexes (shear index, simple shear strain, maximum surface settlement) for assessing stability on the basis of surface or subsurface settlement monitoring are presented. Field experiences with the Kuriyama tunnel are used to illustrate the procedure.
905482 Assessment of tunnel face stability by back analysis Hisatake, M Proc 2nd International Symposium on Field Measurements in Geomechanics, Kobe, 6-9 April 1987 II2, P1217-1224. Publ Rotterdam: A A Balkema, 1988
905486 Slot-drilling and splitting method for tunnel driving Hagimori, K; Watanabe, H; Nakagawa, K; Furakawa, K Proc MMIJ/ IMM Joint Symposium, Today's Technology for the Mining and Metallurgical Industries, Kyoto, 2-4 October 1989 P155-160. Publ London." MMIJ/IMM, 1989
A 3-dimensional finite element back analysis approach to the determination of stability at the tunnel face is presented. Mechanical properties and excavation stresses released at the face must be determined beforehand. The validity of the procedure is demonstrated by comparing maximum shear stress in the lining caused by excavation using the SA (Sequence Analysis) method with real and back analysed input data.
Construction of tunnels by blasting in urban areas or areas close to existing structures tends to cause problems due to vibrations, and low vibration or non-blasting tunnelling methods are becoming esential. Slot-drilling and splitting techniques have been developed for these purposes. Characteristics of these methods and their applications for low vibration tunnelling are discussed with reference to a tunnel in compentent granitic rock.
905483 Technique of field ~ m e n t interpretation in erecting underground openings of round section Bulychev, N S; Savin, I I Proc 2rid imertmtiomd Symposium on Field Measurements in Geomechanics, Kobe, 6-9 April 1987 I/2, P1225-1230. Pub/ Rotterdam: A A Balkema, 1988
905487 Watertight lining systems to secure leaking shafts Valk, J Proc Conference on Shaft Emgineeriog, Harrogate, 5-7 June 1989 P353-363. Publ London: IMM, 1989
A method for the design of multilayer linings for deep, circular tunnels is presented. It is based on analysis of stresses and deformations measured at an arbitrary contact of a monolayer lining or upon a contact of the lining with the rock mass. The initial stress state and effects of time lag in erecting the lining are evaluated without dependence on the geometry or materials properties of the lining in which the measurements are made, and thus may be used in the design of other linings for similar conditions.
The development and design of new lining systems to secure older leaking or unstable shafts are described. Three systems were developed: (1) reinforced concrete cylinder with outer welded steel liner and asphalt layer; (2)jointless reinforced concrete cylinder with asphalt layer; and (3) fully welded steel liner with concrete backfill and chemical seal ring. Two case studies are presented to illustrate planning and design, choice of lining system, structural design and execution of work using systems (2) and (3).
© 1990 Pergamon Press plc. Reproduction not permitted