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Cyclic axial pile loading analyses: a comparative study
185A 933360 Design and performance of fom~latlom for the Canary Wharf development hi London Docklan~ Troughton, V M Geoteelmique V42, N3, Sept 1992, 1'383-393
Foundations See also: 933104, 933164, 933255 933356 Anolytieal model of an innovative pile test E1 Naggar, M H; Novak, M Can Geoteeh J V29, N4, Aug 1992, t'569-579 A new rapid method to assess pile bearing capacity is presented which is applicable to both driven and cast-in-place piles. The statnamic test employs short duration loads applied using a pressure chamber and a reaction mass. Immediate load-displacement and load-time histories are recorded using microprocessor based instrumentation. The mathematical model takes into account slip and energy dissipation, and the parameters involved are, in general, directly related to standard geotechnical parameters. Examples of use and results of statnamic testing are presented and discussed. 933357 PmbalJliistie bearing capacity analysis of jack-up structures Nadim, F; Lacasse, S Can Geotech Y V29, N4, Aug 1992, 1'580-588 Bearing capacity of jack-up spud can foundations is strongly dependent on the installation procedure of the unit. A probabilistic bearing capacity analysis is presented which includes three main steps: a priori calculation of the bearing capacity interaction diagram of a spud can; updating the diagram from vertical preloading; and bearing capacity calculation under environmental loads. Effects of spatial variability, consolidation time, loading rate, and cyclic loading on the strength of foundation clays can be taken into account. An illustrative example is shown. 933358 Cyclic axial pile loading analyses: a comparative study Chin, J T; Poulos, H G Comput Geotech V13, N3, 1992, P137-158 Four numerical approaches for analysis of cyclic loading of vertical piles are described. They are RATZ (load transfer), SCARP (simplified boundary element continuum model with strain softening soil), AXCAP (simplified boundary element model with nonlinear Ramberg-Osgood soil), and SCPIL3 (nonlinear hyperbolic load transfer). The test pile is a hypothetical offshore drilled and grouted pile subject to storm loading. Predicted initial static responses are in good agreement, but cyclic loading predictions, especially accumulated pile displacements, show greater variation. 933359 Numerical evaluation of beating capacity of a foundation in strain softening soil. Techaleal note Pietruszczak, S; Niu, X Comput Geoteeh VI3, N3, 1992, P187-198 The case of a soil mass supported by a retaining wall and subject to loading by a rigid footing is examined. The collapse load of the system is determined for three progressively more complex plasticity formulations: elastic-perfectly plastic, deviatoric hardening, and deviatoric hardening/softening. The dependence of collapse load on chosen constitutive model, in particular when locally unstable strain softening is admitted, is demonstrated.
The commercial development at Canary Wharf is on a site once part of the West India Docks. The geological profile shows alluvial clays and gravel over Woolwich and Reading beds (typically 12m thick), about 15m of Thanet sand, then Upper Chalk. Foundation design philosophy required consideration of previous development, rapid construction requirements, and adjacent building works. Piles ending in the dense Thanet sand were adopted. A variety of pile types has been used, depending on the surface structure, including driven steel piles, bored piles with and without base grouting, and continuous flight auger piles. 933361 New method for single pile settlement prediction and analysis Fleming, W G K Geotecimique V42, N3, Sept 1992, P411-425 An accurate yet simple procedure is presented for predicting the behaviour of single piles under maintained loading, which is based on combination of hyperbolic functions to describe individual shaft and base performance plus consideration of elastic pile shortening. Its validity has been confirmed for a wide variety of soils. Provided pile settlement is sufficient that the latter part of each relation is well defined beyond the stage where shaft friction is close to a constant value, all the main parameters can be obtained by back analysis and used in performance prediction. 933362 Backfill-stiffennd foundation wall design Nicholls, R J Geoteeh Engng Div ASCE Vl18, Nll, Nov 1992, P18221836 Problems can arise when constructing small foundations due to overeompaction of the soil mass. A construction method is described in which lightweight sandwich panels (mortar-faced polystyrene foam core) are assembled and a lightweight concrete fill (containing flyash and recycled polystyrene foam aggregate) is poured in two lifts.The wet fillexerts only low pressure on the walls. Design examples use laboratory testvalues and illustrate calculations to obtain minimum cost/minimum bending stiffness. 933363 Large-scale loading tests of shallow footings in pneumatic caisson Kusakabe, O; Maeda, Y; Ohuchi, M J Geoteck Engng Div ASCE Vl18, Nll, Nov 1992, P16811695
To examine the bearing capacity of foundations on a naturally deposited dense volcanic material (scoria) with SPT N count °70, a series of model tests was carried out within a pneumatic caisson. The weight of the caisson body and ballast water was available as a large reaction force. Footings of area up to 1.69 sq m were tested at the base of the caisson at several stages during its excavation. A size effect on foundation capacity is found. A finite difference numerical method has been developed to predict bearing capacity. Visible shear bands due to particle crushing developed during failure under high pressure loading.
© 1993 Pergamon Press Ltd. Reproduction not permitted
Foundations See also: 933104, 933164, 933255 933356 Anolytieal model of an innovative pile test E1 Naggar, M H; Novak, M Can Geoteeh J V29, N4, Aug 1992, t'569-579 A new rapid method to assess pile bearing capacity is presented which is applicable to both driven and cast-in-place piles. The statnamic test employs short duration loads applied using a pressure chamber and a reaction mass. Immediate load-displacement and load-time histories are recorded using microprocessor based instrumentation. The mathematical model takes into account slip and energy dissipation, and the parameters involved are, in general, directly related to standard geotechnical parameters. Examples of use and results of statnamic testing are presented and discussed. 933357 PmbalJliistie bearing capacity analysis of jack-up structures Nadim, F; Lacasse, S Can Geotech Y V29, N4, Aug 1992, 1'580-588 Bearing capacity of jack-up spud can foundations is strongly dependent on the installation procedure of the unit. A probabilistic bearing capacity analysis is presented which includes three main steps: a priori calculation of the bearing capacity interaction diagram of a spud can; updating the diagram from vertical preloading; and bearing capacity calculation under environmental loads. Effects of spatial variability, consolidation time, loading rate, and cyclic loading on the strength of foundation clays can be taken into account. An illustrative example is shown. 933358 Cyclic axial pile loading analyses: a comparative study Chin, J T; Poulos, H G Comput Geotech V13, N3, 1992, P137-158 Four numerical approaches for analysis of cyclic loading of vertical piles are described. They are RATZ (load transfer), SCARP (simplified boundary element continuum model with strain softening soil), AXCAP (simplified boundary element model with nonlinear Ramberg-Osgood soil), and SCPIL3 (nonlinear hyperbolic load transfer). The test pile is a hypothetical offshore drilled and grouted pile subject to storm loading. Predicted initial static responses are in good agreement, but cyclic loading predictions, especially accumulated pile displacements, show greater variation. 933359 Numerical evaluation of beating capacity of a foundation in strain softening soil. Techaleal note Pietruszczak, S; Niu, X Comput Geoteeh VI3, N3, 1992, P187-198 The case of a soil mass supported by a retaining wall and subject to loading by a rigid footing is examined. The collapse load of the system is determined for three progressively more complex plasticity formulations: elastic-perfectly plastic, deviatoric hardening, and deviatoric hardening/softening. The dependence of collapse load on chosen constitutive model, in particular when locally unstable strain softening is admitted, is demonstrated.
The commercial development at Canary Wharf is on a site once part of the West India Docks. The geological profile shows alluvial clays and gravel over Woolwich and Reading beds (typically 12m thick), about 15m of Thanet sand, then Upper Chalk. Foundation design philosophy required consideration of previous development, rapid construction requirements, and adjacent building works. Piles ending in the dense Thanet sand were adopted. A variety of pile types has been used, depending on the surface structure, including driven steel piles, bored piles with and without base grouting, and continuous flight auger piles. 933361 New method for single pile settlement prediction and analysis Fleming, W G K Geotecimique V42, N3, Sept 1992, P411-425 An accurate yet simple procedure is presented for predicting the behaviour of single piles under maintained loading, which is based on combination of hyperbolic functions to describe individual shaft and base performance plus consideration of elastic pile shortening. Its validity has been confirmed for a wide variety of soils. Provided pile settlement is sufficient that the latter part of each relation is well defined beyond the stage where shaft friction is close to a constant value, all the main parameters can be obtained by back analysis and used in performance prediction. 933362 Backfill-stiffennd foundation wall design Nicholls, R J Geoteeh Engng Div ASCE Vl18, Nll, Nov 1992, P18221836 Problems can arise when constructing small foundations due to overeompaction of the soil mass. A construction method is described in which lightweight sandwich panels (mortar-faced polystyrene foam core) are assembled and a lightweight concrete fill (containing flyash and recycled polystyrene foam aggregate) is poured in two lifts.The wet fillexerts only low pressure on the walls. Design examples use laboratory testvalues and illustrate calculations to obtain minimum cost/minimum bending stiffness. 933363 Large-scale loading tests of shallow footings in pneumatic caisson Kusakabe, O; Maeda, Y; Ohuchi, M J Geoteck Engng Div ASCE Vl18, Nll, Nov 1992, P16811695
To examine the bearing capacity of foundations on a naturally deposited dense volcanic material (scoria) with SPT N count °70, a series of model tests was carried out within a pneumatic caisson. The weight of the caisson body and ballast water was available as a large reaction force. Footings of area up to 1.69 sq m were tested at the base of the caisson at several stages during its excavation. A size effect on foundation capacity is found. A finite difference numerical method has been developed to predict bearing capacity. Visible shear bands due to particle crushing developed during failure under high pressure loading.
© 1993 Pergamon Press Ltd. Reproduction not permitted