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Static response of an orthotropic stratified medium to surface loads - strip footings
251A 924354 One-dimensional analysis of soil plugs in pipe piles Randolph, M F; Leong, E C; Houlsby, G T Geoteelmblue V41, N4, Dec 1991, t)587-598
924358 Pile capacity for axial cyclic loading Boa, R G J Geoteck Engng Div ASCE VlI8. NI, Jan 1992, P34-50
Open ended pipe piles will generally fail in the plugged mode during drained compression loading as arching action within the pile leads to high frictional capacity of the plug. Under the faster rates of loading in offshore environments, plug capacity will be lower due to the limited increases of effective stresses within the soil plug. A simple one dimensional analysis of the soil plug capacity under partially drained conditions is presented. Design charts are developed which show plug capacity as a function of soil plug parameters and loading rate. Example calculations are presented for typical offshore conditions in calcareous soils.
The effects of storm wave loading on axial capacity of piles of an offshore structure in cohesive soil have been analysed. Pilesoil interaction under intense cyclic loading is examined using the program PAR (Pile Analysis Routines), a time domain, nonlinear discrete element model. Data used are for a platform in 300m of water in the Gulf of Mexico. Loading rate, ratio of static to cyclic load amplitude, number and sequence of cycles, and relative pile to soil stiffness have major impact on performance. Safety factors are evaluated for a range of loading scenarios.
924355 Device for control of building settlement and for seismic protection Aguirre, M J Geotech Engng Div ASCE VII7, NI2, Dec 1991, P18481859 Where heavy structures are founded on deep end bearing piles and regional consolidation of compressible subsoils results in sinking of the ground surface, damage can occur to pavements, utilities and adjacent structures. To prevent this in Mexico City, the control pile device has been developed, such that the building neither settles nor emerges relative to the surrounding ground. Part of the building load is transmitted to foundation piles via layers of cubes of a local wood (CaobiUa) which behaves in a roughly elastoplastic manner. The device is fixed to the head of the piles, which pass freely through the foundation slab and are connected to it via anchor bolts. It also provides a degree of seismic protection. 924356 Model for capacity of single piles in sand using fuzzy sets Juang, C H; Wey, J L; Elton, D J J Geotech Engng Div ASCE VII7, NI2, Dec 1991, P19201931 The incomplete understanding of soil-pile.interaction and the limited quantity and inexact quality of subsurface data make prediction of bearing capacity of piles in cohesionless soil problematical. Uncertainties in the method of calculation and in the data used cannot be quantified in many cases. The use of fuzzy set theory is proposed to account for these uncertaintes. Qualitative information and subjective judgement can be included in the computations. A computer program PCFS (prediction of pile capacity using fuzzy sets) has been developed and is illustrated for improved prediction of the beating capacity of a single pile in sand. 924357 Bearing capacity of clay overlain by stiff soil. Technical note Madhav, M R; Sharma, J S N J Geotech Engng Div ASCE VII7, NI2, Dec 1991, P19411948 The bearing capacity of a footing resting on a stiff layer underlain by soft clay has been investigated. The effect of the stiff layer is to distribute the uniform applied stress over a larger width than if it is absent. Loading on the clay is uniform over a width B, then decreases linearly or exponentially with distance. Increase in bearing capacity of 20-30% is possible where surcharge stress extends over a distance 5B and the ratio of elastic moduli of the soil layers is 100. Similar results are seen for triangular loading.
924359 Driving characteristics of open-toe piles in dense sand Raines, R D; Ugaz, O G; O'Neill, W J Geotech Engng Div ASCE VII8, NI, Jan 1992, P73-87 Model tests were carried out in a pressure chamber with 102mm o.d. pipe piles driven into dense saturated sand at constant hammer energy. Interactions with the soil plug and effects of pile toe geometry on driving were examined and wave equation parameters evaluated. Test data and finite element simulations suggest that no piles plug solidly at depths of penetration up to 21 diameters, and that thickened, bevel toed piles are more easily driven than plain toed piles. The one dimensional wave equation models behaviour accurately only after empirical adjustments of values of commonly used parameters.
924360 Static response of an orthotropic stratified medium to surface loads - strip footings Garg, N R; Sharma, R K Phys Earth Planet Inter V69, NI/2, Nov 1991, P20-36 The study of horizontally layered systems under surface loading has many applications in engineering. Orthotropic symmetry is a property of principal rock forming minerals of the earth crust. Static deformation of an orthotropic multilayered elastic medium is examined with a transfer matrix approach used to evaluate displacements and stresses in the medium. Plane and antiplane strain cases are considered. Two examples are presented, where the multilayered medium is in welded contact with an elastic half space and when it lies on a rigid base.
924361 Foundations on intermediate cushion of variable stiffness Sorochan, E A; Bysutenko, O V; Likhovtsev, V M Soil Meek Found Engng V28, NI, Jan-Feb 1991, P12-15 The use of an intermediate cushion of variable stiffness to lower materials consumption for site preparation and substructure installation is described. In one case a bed of 5-10 cm of loose sand and concrete was laid directly on the soil base. In another, concrete slabs of width 0.3-0.8 foundation width were pressed directly into the soil. Stress distribution beneath footings installed on the cushion and settlements have been studied. Settlement nonuniformity can be reduced by using an intermediate cushion with rigid portion width adjusted in accordance with relative load intensity.
© 1992 Pergamon Press Ltd. Reproduction not permitted
924358 Pile capacity for axial cyclic loading Boa, R G J Geoteck Engng Div ASCE VlI8. NI, Jan 1992, P34-50
Open ended pipe piles will generally fail in the plugged mode during drained compression loading as arching action within the pile leads to high frictional capacity of the plug. Under the faster rates of loading in offshore environments, plug capacity will be lower due to the limited increases of effective stresses within the soil plug. A simple one dimensional analysis of the soil plug capacity under partially drained conditions is presented. Design charts are developed which show plug capacity as a function of soil plug parameters and loading rate. Example calculations are presented for typical offshore conditions in calcareous soils.
The effects of storm wave loading on axial capacity of piles of an offshore structure in cohesive soil have been analysed. Pilesoil interaction under intense cyclic loading is examined using the program PAR (Pile Analysis Routines), a time domain, nonlinear discrete element model. Data used are for a platform in 300m of water in the Gulf of Mexico. Loading rate, ratio of static to cyclic load amplitude, number and sequence of cycles, and relative pile to soil stiffness have major impact on performance. Safety factors are evaluated for a range of loading scenarios.
924355 Device for control of building settlement and for seismic protection Aguirre, M J Geotech Engng Div ASCE VII7, NI2, Dec 1991, P18481859 Where heavy structures are founded on deep end bearing piles and regional consolidation of compressible subsoils results in sinking of the ground surface, damage can occur to pavements, utilities and adjacent structures. To prevent this in Mexico City, the control pile device has been developed, such that the building neither settles nor emerges relative to the surrounding ground. Part of the building load is transmitted to foundation piles via layers of cubes of a local wood (CaobiUa) which behaves in a roughly elastoplastic manner. The device is fixed to the head of the piles, which pass freely through the foundation slab and are connected to it via anchor bolts. It also provides a degree of seismic protection. 924356 Model for capacity of single piles in sand using fuzzy sets Juang, C H; Wey, J L; Elton, D J J Geotech Engng Div ASCE VII7, NI2, Dec 1991, P19201931 The incomplete understanding of soil-pile.interaction and the limited quantity and inexact quality of subsurface data make prediction of bearing capacity of piles in cohesionless soil problematical. Uncertainties in the method of calculation and in the data used cannot be quantified in many cases. The use of fuzzy set theory is proposed to account for these uncertaintes. Qualitative information and subjective judgement can be included in the computations. A computer program PCFS (prediction of pile capacity using fuzzy sets) has been developed and is illustrated for improved prediction of the beating capacity of a single pile in sand. 924357 Bearing capacity of clay overlain by stiff soil. Technical note Madhav, M R; Sharma, J S N J Geotech Engng Div ASCE VII7, NI2, Dec 1991, P19411948 The bearing capacity of a footing resting on a stiff layer underlain by soft clay has been investigated. The effect of the stiff layer is to distribute the uniform applied stress over a larger width than if it is absent. Loading on the clay is uniform over a width B, then decreases linearly or exponentially with distance. Increase in bearing capacity of 20-30% is possible where surcharge stress extends over a distance 5B and the ratio of elastic moduli of the soil layers is 100. Similar results are seen for triangular loading.
924359 Driving characteristics of open-toe piles in dense sand Raines, R D; Ugaz, O G; O'Neill, W J Geotech Engng Div ASCE VII8, NI, Jan 1992, P73-87 Model tests were carried out in a pressure chamber with 102mm o.d. pipe piles driven into dense saturated sand at constant hammer energy. Interactions with the soil plug and effects of pile toe geometry on driving were examined and wave equation parameters evaluated. Test data and finite element simulations suggest that no piles plug solidly at depths of penetration up to 21 diameters, and that thickened, bevel toed piles are more easily driven than plain toed piles. The one dimensional wave equation models behaviour accurately only after empirical adjustments of values of commonly used parameters.
924360 Static response of an orthotropic stratified medium to surface loads - strip footings Garg, N R; Sharma, R K Phys Earth Planet Inter V69, NI/2, Nov 1991, P20-36 The study of horizontally layered systems under surface loading has many applications in engineering. Orthotropic symmetry is a property of principal rock forming minerals of the earth crust. Static deformation of an orthotropic multilayered elastic medium is examined with a transfer matrix approach used to evaluate displacements and stresses in the medium. Plane and antiplane strain cases are considered. Two examples are presented, where the multilayered medium is in welded contact with an elastic half space and when it lies on a rigid base.
924361 Foundations on intermediate cushion of variable stiffness Sorochan, E A; Bysutenko, O V; Likhovtsev, V M Soil Meek Found Engng V28, NI, Jan-Feb 1991, P12-15 The use of an intermediate cushion of variable stiffness to lower materials consumption for site preparation and substructure installation is described. In one case a bed of 5-10 cm of loose sand and concrete was laid directly on the soil base. In another, concrete slabs of width 0.3-0.8 foundation width were pressed directly into the soil. Stress distribution beneath footings installed on the cushion and settlements have been studied. Settlement nonuniformity can be reduced by using an intermediate cushion with rigid portion width adjusted in accordance with relative load intensity.
© 1992 Pergamon Press Ltd. Reproduction not permitted