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Strength for static and dynamic stability analysis
117A 902423 Validity of Smith model in pile driving analysis Wu, A K H; Kuhlemeyer, R L; To, C W S J Geotech gngng Div ASCE V115, N9, Sept 1989, P12851302 Smith (1960) developed a wave equation analysis for pile driving, idealizing the system as a series of masses and springs. Soil parameters used were proposed on the basis of field experience. An analytical method using dynamic finite element analysis is used to determine the shaft damping parameter and relate it to soil shear modulus and shear strength. Relations between shaft damping parameter and penetration velocity, radius of yielding zone, and force pulse duration are also examined. The damping parameter cannot be back calculated to be some simple constant.
902427 Hybrid modelling of single piles Chen, C H Proc Ninth Southeast Asian Geotechnical Conference, Bangkok, 7-11 December 1987 ~ . P6.253-6.264. Publ Bangkok: Southeast Asian Geotechnical Society, 1987 A hybrid method using the technique of substructuring is presented for dynamic analysis of single piles embedded in a homogeneous viscoelastic half space. The near field is modelled by finite elements and the semi-infinite far field by an impedance matrix. Solid, beam and rig link, and beam elements are used to model the pile. A slender pile can be modelled well by each of the three methods, but the beam element model may underestimate impedance of a short pile.
902424 Structural response to ground vibration from blasting in opencast coal mines Adhikari, G R; Singh, R B; Gupta, R N J Min Metal Fuels V37, N4. April 1989, P135-138
902428 Static and dynamic behaviour of pile foundations Chandrasekaran, V; Cook, D J; Cao, H T Proc Ninth Southeast Asian Geotechnical Conference, Bangkok, 7-11 December 1987 I/2, P6.265-6.276. Publ Bangkok: Southeast Asian Geotechnical Society, 1987
Observed structural damage could not be explained in terms of peak particle velocities. Damage was recorded at a distance of lkm where PPV was below 7mm/s. Spectral analysis of blast vibrations indicated a low frequency content. Further investigations of single storied structures showed they had natural frequencies of 8-14Hz, and that ground vibrations were amplified by the structure itself. Both PPV and spectral content should be considered when assessing damage potential of blasting.
Dynamic behaviour of pile foundations is analysed with the soil pile system idealised as a lumped-mass-spring system. The analysis is performed using transfer matrix techniques, model analysis, and determinant search methods. Natural frequencies and model quantities are evaluated for various modes of vibration for piles embedded in soils of constant modulus, modulus varying linearly with depth, and for layered soils, as well as for excitation simulating the N-S component of the El Centro (1940) earthquake.
902425 Strength for static and dynamic stability analysis
902429 Modelling of pipe/soil interactions in flexible risers Kodaissi, E; Narzul, P Proc BOSS'88, Trondheim, June 1988 VI, P279-293. Publ Trondheim: Tapir. 1988
Poulos, S J
Proc Conference on Hydraulic Fill Structures, Fort Collins, 13-18 April 1988 P452-474. Publ New York: ASCE, 1988 (Geotechnical Special Publication No 21) A review of case histories shows most failures in embankments occur in soils with a large ratio of peak to steady state strength in the field. Failure of sands in undrained contractive shear is discussed, considering stable, unstable and metastable conditions, strains in situ and progressive failure, and stability and deformation problems. The points made are illustrated by evaluation of standard procedures to select safety factor and shear strength. It is recommended that steady state strength be measured and used to compute safety factor for stability analysis, as this avoids reliance on peak strength which may be destroyed by progressive strains in situ. 33 refs.
902426 Evaluation of seismic behavior of hydraulic fill structures Troncoso, J H Proc Conference on Hydraulic Fill Structures, Fort Collins, 13-18 April 1988 P475-491. Publ New York: ASCE. 1988 (Geotechnical Special Publication No 21) Seismic behaviour of hydraulic fill structures was examined theoretically and from observations during the 1985 Chile earthquake. Finite element analysis was used for static analysis of structure behaviour, particularly response of dams at various heights to different seismic ground motions. The analyses identify some zones where instrumentation is necessary, and that seismic response changes as height increases. Observations on dams during the 1985 earthquake are discussed. Two dams liquefied, and damage to others is outlined.
Flexible pipes are used in offshore floating structures. For analysis of pipe/seabed soil interaction, wave and current actions and the motions of the floating production vessel must be taken into account. If interactions between two risers of different characteristics or a riser and a mooring line are to be considered, a model which includes on-bottom friction of the riser must be used. A three dimensional finite element program, FLEXAN-C, is applied to this problem. Soil-pipe friction is assumed to be of the Coulomb type, and the soil-pile interface taken to be perfectly plastic. Application to several practical cases is presented.
902430 Stability design of marine pipelines Sotberg, T; Lambrakos, K F; Remseth, S; Verley, R L P; Wolfram, W R Proc BOSS'88, Trondheim, June 1988 II1, P295-310. Publ Trondheim: Tapir. 1988 The response program PONDUS, developed during the PIPESTAB program, is used to model the response of a seafloor pipeline to wave loading. The model assumes linearly elastic material properties, a flat bottom, homogeneous soil, and waves propagating perpendicular to the pipe. For sand soils, limited pipeline movement and strain is permitted for extreme sea states, but for soft to medium clay soils, absolute stability is required. The design method determines the pipe weight which satisfies given criteria for acceptable pipeline response.
© 1990 Pergamon Press pie. Reproduction not permitted RMMS 27 2--1
902427 Hybrid modelling of single piles Chen, C H Proc Ninth Southeast Asian Geotechnical Conference, Bangkok, 7-11 December 1987 ~ . P6.253-6.264. Publ Bangkok: Southeast Asian Geotechnical Society, 1987 A hybrid method using the technique of substructuring is presented for dynamic analysis of single piles embedded in a homogeneous viscoelastic half space. The near field is modelled by finite elements and the semi-infinite far field by an impedance matrix. Solid, beam and rig link, and beam elements are used to model the pile. A slender pile can be modelled well by each of the three methods, but the beam element model may underestimate impedance of a short pile.
902424 Structural response to ground vibration from blasting in opencast coal mines Adhikari, G R; Singh, R B; Gupta, R N J Min Metal Fuels V37, N4. April 1989, P135-138
902428 Static and dynamic behaviour of pile foundations Chandrasekaran, V; Cook, D J; Cao, H T Proc Ninth Southeast Asian Geotechnical Conference, Bangkok, 7-11 December 1987 I/2, P6.265-6.276. Publ Bangkok: Southeast Asian Geotechnical Society, 1987
Observed structural damage could not be explained in terms of peak particle velocities. Damage was recorded at a distance of lkm where PPV was below 7mm/s. Spectral analysis of blast vibrations indicated a low frequency content. Further investigations of single storied structures showed they had natural frequencies of 8-14Hz, and that ground vibrations were amplified by the structure itself. Both PPV and spectral content should be considered when assessing damage potential of blasting.
Dynamic behaviour of pile foundations is analysed with the soil pile system idealised as a lumped-mass-spring system. The analysis is performed using transfer matrix techniques, model analysis, and determinant search methods. Natural frequencies and model quantities are evaluated for various modes of vibration for piles embedded in soils of constant modulus, modulus varying linearly with depth, and for layered soils, as well as for excitation simulating the N-S component of the El Centro (1940) earthquake.
902425 Strength for static and dynamic stability analysis
902429 Modelling of pipe/soil interactions in flexible risers Kodaissi, E; Narzul, P Proc BOSS'88, Trondheim, June 1988 VI, P279-293. Publ Trondheim: Tapir. 1988
Poulos, S J
Proc Conference on Hydraulic Fill Structures, Fort Collins, 13-18 April 1988 P452-474. Publ New York: ASCE, 1988 (Geotechnical Special Publication No 21) A review of case histories shows most failures in embankments occur in soils with a large ratio of peak to steady state strength in the field. Failure of sands in undrained contractive shear is discussed, considering stable, unstable and metastable conditions, strains in situ and progressive failure, and stability and deformation problems. The points made are illustrated by evaluation of standard procedures to select safety factor and shear strength. It is recommended that steady state strength be measured and used to compute safety factor for stability analysis, as this avoids reliance on peak strength which may be destroyed by progressive strains in situ. 33 refs.
902426 Evaluation of seismic behavior of hydraulic fill structures Troncoso, J H Proc Conference on Hydraulic Fill Structures, Fort Collins, 13-18 April 1988 P475-491. Publ New York: ASCE. 1988 (Geotechnical Special Publication No 21) Seismic behaviour of hydraulic fill structures was examined theoretically and from observations during the 1985 Chile earthquake. Finite element analysis was used for static analysis of structure behaviour, particularly response of dams at various heights to different seismic ground motions. The analyses identify some zones where instrumentation is necessary, and that seismic response changes as height increases. Observations on dams during the 1985 earthquake are discussed. Two dams liquefied, and damage to others is outlined.
Flexible pipes are used in offshore floating structures. For analysis of pipe/seabed soil interaction, wave and current actions and the motions of the floating production vessel must be taken into account. If interactions between two risers of different characteristics or a riser and a mooring line are to be considered, a model which includes on-bottom friction of the riser must be used. A three dimensional finite element program, FLEXAN-C, is applied to this problem. Soil-pipe friction is assumed to be of the Coulomb type, and the soil-pile interface taken to be perfectly plastic. Application to several practical cases is presented.
902430 Stability design of marine pipelines Sotberg, T; Lambrakos, K F; Remseth, S; Verley, R L P; Wolfram, W R Proc BOSS'88, Trondheim, June 1988 II1, P295-310. Publ Trondheim: Tapir. 1988 The response program PONDUS, developed during the PIPESTAB program, is used to model the response of a seafloor pipeline to wave loading. The model assumes linearly elastic material properties, a flat bottom, homogeneous soil, and waves propagating perpendicular to the pipe. For sand soils, limited pipeline movement and strain is permitted for extreme sea states, but for soft to medium clay soils, absolute stability is required. The design method determines the pipe weight which satisfies given criteria for acceptable pipeline response.
© 1990 Pergamon Press pie. Reproduction not permitted RMMS 27 2--1