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Axial capacity of steel pile piles in sand
157A geotechnical site investigation techniques for reducing failure are described. Different analytical procedures of possible use in predicting safe foundation performance are reviewed. 40 refs.
855165 Group action in offshore piles O'Neill, M W Proc Conference on Geotechnical Practice in Offshore Engineering, Austin, Texas, 27-29 April 1983 P25-64. Publ New York: ASCE, 1983 A review of work to date on grouped-pile foundations for offshore structures. Design considerations, pile-soil interaction on sand, clay and layered soils, flexibility and loading are all discussed. Extensive use is made of model pile data, data from onshore piles and mathematical modelling. 199 refs.
855166 Dynamic fluid-structure-soil interaction Prevost, J H: Hughes. TJ R Proc Conference on Geotechnical Practice in Offshore Engineering, Austin, Texas, 27-29 April 1983 P133-143. Puhl New York: ASCE, 1983 A general finite element model is proposed for dynamic fluidstructure-soil interaction problems experienced in offshore engineering. The procedure permits realistic modelling of the fluid domain and its free surface and the two phase (soil skeleton and pore fluid) saturated foundation soil domain.
855167 Group effect on piles in a liquefying sand deposit De Alba, P A Proc Conference on Geotechnicai Practice in Offshore Engineering, Austin, Texas, 27-29 April 1983 P300-314. Publ New York~ .4SCE, 1983 Tests modelling the behaviour of single and grouped cylindrical piles, in a liquefiable medium over a rigid base, indicate that, as pore pressure increases, groups settle more slowly than single piles. The difference in behaviour is a function of pile diameter and pile tip-solid base distance, but becomes unimportant if this ratio falls below about 1:8. In deep deposits there is no difference in settling rate. The behaviour was consistent for pile groups and single piles when compared in dimensionless terms. This suggests test results may provide insight into the performance of full size pile groups.
855168 Torsional behaviour of model piles in sand Dutt, R N; O'Neill, M W Proc Conference on Geotechnicai Practice in Offshore Engineering, Austin, Texas, 27-29 April 1983 P315-334. Publ New York: ASCE, 1983 The torsional behaviour of large model piles in sand was studied to formulate a criterion describing the soil-pile interaction in the form of non-linear soil reaction curves. These curves were used in a numerical model to simulate pile-head-torque-twist behaviour. Shear transfer was essentially constant below a normalised depth and was largely dependent on pile shape and sand density. It was emphasised that without information from fullscale testing, care should be taken when applying this model to real structures.
855169 Uplift resistance of model single piles Chaudhuri. K P R: Symons. M V Proc Conference on Geotechnical Practice in Offshore Engineering, Austin, Texas, 27-29 April 1983 P335-355. Publ .\'~w York. ,4SCE. 1983
Instrumented cylindrical single model piles, of different diameters, length, surface roughness and embedment depth, were subjected to uplift loading tests from dense and medium sand. Surface roughness and sand density determined the shape of the load-displacement curve. Uplift load transfer mechanisms were evaluated by measuring axial Ioadings within the piles and calculating shear stress distribution. The depths beyond which average frictional resistance reaches constant values are defined for the various pile/sand combinations. The test results are compared with previous work and theoretical analyses.
855 ! 70 Model tests of piles in calcareous sands Nauroy, J F; Le TiranL P Proc Conference on Geotechnical Practice in Offshore Engineering, Austin, Texas, 27-29 April 1983 P356-369. Puhl New York: ASCE, 1983 Model piles were embedded in non-cemented calcareous sands by jacking and driving and variation of lateral pressure with penetration depth measured. Skin friction was measured during pullout tests. Compressibility, a factor integrating effects of mechanical, physical and microstructural properties of the sand, was found to have a major influence on results. The final value of normal stress on the pile wall was dependent on compressibility and could be less than the initial value, explaining low skin friction in calcareous sands. End bearing capacity was found to become less as sand compressibility increased. There was insufficient data to specify the relationship between skin friction and compressibility.
855171 Axial capacity of steel pipe piles in clay Dennis, N D; Olson, R E Proc Conference on G e o t e c h n i c a l Practice in Offshore Engineering, Austin, Texas, 27-29 April 1983 P370-388. Publ New York: ASCE, 1983 Pile capacities from a data base of 84 load tests were compared with values predicted by five methods. The two lambda methods had least scatter but overpredicted capacity by about 20%. The API method had more scatter and overpredicted by about 1300. The two alpha methods had largest scatter and largest difference between measured and predicted capacity. It is suggested that scatter can be reduced by using a standardised soil shear strength measured on samples prepared by a standardised method. Excellent prediction of capacity and reduced scatter was obtained using a modified alpha method with this standardised strength and a length correction factor.
855172 Axial capacity of steel pile piles in sand Dennis, N D; Olson, R E Proc Conference on Geotechnieal Practice in Offshore Engineering, Austin, Texas, 27-29 April 1983 P389-402. Publ New York. ASCE, 1983 Data were collected for 66 axial loading tests, essentially to failure, for steel pipe piles in cohesionless soils. Measured bearing capacities were compared with those predicted by the APIS method, which gave a large scatter, 0.2-11.0 times measured values and average 20%o overprediction. A revised method of analysis was formulated which used an extended classification system accounting for soil density and grain hardness. This reduced both scatter and overprediction.
855165 Group action in offshore piles O'Neill, M W Proc Conference on Geotechnical Practice in Offshore Engineering, Austin, Texas, 27-29 April 1983 P25-64. Publ New York: ASCE, 1983 A review of work to date on grouped-pile foundations for offshore structures. Design considerations, pile-soil interaction on sand, clay and layered soils, flexibility and loading are all discussed. Extensive use is made of model pile data, data from onshore piles and mathematical modelling. 199 refs.
855166 Dynamic fluid-structure-soil interaction Prevost, J H: Hughes. TJ R Proc Conference on Geotechnical Practice in Offshore Engineering, Austin, Texas, 27-29 April 1983 P133-143. Puhl New York: ASCE, 1983 A general finite element model is proposed for dynamic fluidstructure-soil interaction problems experienced in offshore engineering. The procedure permits realistic modelling of the fluid domain and its free surface and the two phase (soil skeleton and pore fluid) saturated foundation soil domain.
855167 Group effect on piles in a liquefying sand deposit De Alba, P A Proc Conference on Geotechnicai Practice in Offshore Engineering, Austin, Texas, 27-29 April 1983 P300-314. Publ New York~ .4SCE, 1983 Tests modelling the behaviour of single and grouped cylindrical piles, in a liquefiable medium over a rigid base, indicate that, as pore pressure increases, groups settle more slowly than single piles. The difference in behaviour is a function of pile diameter and pile tip-solid base distance, but becomes unimportant if this ratio falls below about 1:8. In deep deposits there is no difference in settling rate. The behaviour was consistent for pile groups and single piles when compared in dimensionless terms. This suggests test results may provide insight into the performance of full size pile groups.
855168 Torsional behaviour of model piles in sand Dutt, R N; O'Neill, M W Proc Conference on Geotechnicai Practice in Offshore Engineering, Austin, Texas, 27-29 April 1983 P315-334. Publ New York: ASCE, 1983 The torsional behaviour of large model piles in sand was studied to formulate a criterion describing the soil-pile interaction in the form of non-linear soil reaction curves. These curves were used in a numerical model to simulate pile-head-torque-twist behaviour. Shear transfer was essentially constant below a normalised depth and was largely dependent on pile shape and sand density. It was emphasised that without information from fullscale testing, care should be taken when applying this model to real structures.
855169 Uplift resistance of model single piles Chaudhuri. K P R: Symons. M V Proc Conference on Geotechnical Practice in Offshore Engineering, Austin, Texas, 27-29 April 1983 P335-355. Publ .\'~w York. ,4SCE. 1983
Instrumented cylindrical single model piles, of different diameters, length, surface roughness and embedment depth, were subjected to uplift loading tests from dense and medium sand. Surface roughness and sand density determined the shape of the load-displacement curve. Uplift load transfer mechanisms were evaluated by measuring axial Ioadings within the piles and calculating shear stress distribution. The depths beyond which average frictional resistance reaches constant values are defined for the various pile/sand combinations. The test results are compared with previous work and theoretical analyses.
855 ! 70 Model tests of piles in calcareous sands Nauroy, J F; Le TiranL P Proc Conference on Geotechnical Practice in Offshore Engineering, Austin, Texas, 27-29 April 1983 P356-369. Puhl New York: ASCE, 1983 Model piles were embedded in non-cemented calcareous sands by jacking and driving and variation of lateral pressure with penetration depth measured. Skin friction was measured during pullout tests. Compressibility, a factor integrating effects of mechanical, physical and microstructural properties of the sand, was found to have a major influence on results. The final value of normal stress on the pile wall was dependent on compressibility and could be less than the initial value, explaining low skin friction in calcareous sands. End bearing capacity was found to become less as sand compressibility increased. There was insufficient data to specify the relationship between skin friction and compressibility.
855171 Axial capacity of steel pipe piles in clay Dennis, N D; Olson, R E Proc Conference on G e o t e c h n i c a l Practice in Offshore Engineering, Austin, Texas, 27-29 April 1983 P370-388. Publ New York: ASCE, 1983 Pile capacities from a data base of 84 load tests were compared with values predicted by five methods. The two lambda methods had least scatter but overpredicted capacity by about 20%. The API method had more scatter and overpredicted by about 1300. The two alpha methods had largest scatter and largest difference between measured and predicted capacity. It is suggested that scatter can be reduced by using a standardised soil shear strength measured on samples prepared by a standardised method. Excellent prediction of capacity and reduced scatter was obtained using a modified alpha method with this standardised strength and a length correction factor.
855172 Axial capacity of steel pile piles in sand Dennis, N D; Olson, R E Proc Conference on Geotechnieal Practice in Offshore Engineering, Austin, Texas, 27-29 April 1983 P389-402. Publ New York. ASCE, 1983 Data were collected for 66 axial loading tests, essentially to failure, for steel pipe piles in cohesionless soils. Measured bearing capacities were compared with those predicted by the APIS method, which gave a large scatter, 0.2-11.0 times measured values and average 20%o overprediction. A revised method of analysis was formulated which used an extended classification system accounting for soil density and grain hardness. This reduced both scatter and overprediction.