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Behavior of vibro-driven piles in sand
105A 912336 Probobilistic response of laterally loaded piers by three-point approximation. Application brief Drumm, E C; Bennett, R M; Oakley, G J lnt J Num Anal Aleth Geomech VI4, N7, Sept-Oct 1990, P499-507
91234O Bearing capacity of expanded-base piles with compacted concrete shafts Neely, W J J Geoteeh Engng Div ASCE VI16, N9, Sept 1990, P13091324
Uncertainty associated with soil properties can arise from several sources. The primary uncertainty herein is the natural variability of the soil, which is included using the discrete three point approximation (3PA) of Rosenblueth. The uncertainty analysis is applied to performance of laterally loaded drilled piles. Observed behaviour and the deterministic solution based on mean values of material properties are seen to be bracketed by the predicted 3PA range of response.
A database of load test results on 71 uncased, expanded base pile in sands at 61 sites was assembled, to assist development of empirical design methods based on SPT N count. Both shaft and end resistance increase with depth and increasing N count. They appear to reach limiting values in loose soils at shaft length/diameter of about 12, but continue increasing at a decreasing rate in denser soils. A modification to traditional bearing capacity theory explains this scale effect as related to decrease in bearing capacity factor (a function of friction angle) with increasing depth or overburden pressure, hence point resistance increases with depth at a decreasing rate.
912337 Settlement analysis of socketed pile groups Chow, Y K; Chin, J T; Kog, Y C; Lee, S L J Geotech Engng Div ASCE VII6, N8, Aug 1990, P11711184 A numerical procedure is presented for settlement analysis of group piles penetrated through an upper soil layer to socket in bearing stratum of finite stiffness. Parametric analysis is used to examine influence of soil, pile, and bearing stratum properties on group performance. Graph data provided allow simple estimation of pile settlement under normal working loads. Applications to settlement of two structures supported on socketed pile groups are illustrated.
912338 Laboratory modeling of vibro-driven piles O'Neill, M W~ Vipulanandan, C, Wong, D J Geotech Engng Div ASCE VII6, N8, Aug 1990. P11901209 102mm diameter instrumented model piles were penetrated into sand in a pressure chamber by vibro-driving and impact. Influence of soil grain size and relative density, vibratory parameters, and restriking with impact on pile performance was studied. Maximum penetration rate was achieved at driving frequency 20Hz, regardless of soil parameters or other driving parameters. Relative density had greatest influence on penetration rate. Static and dynamic load-transfer curves are developed for vibratory driving and compared to those for impact. Impact driven piles have greater bearing capacity than vibration driven piles at 65% soil relative density, lower at 95% relative density.
912341 Foundation-response predictions below caisson-retained island Kaliakin, V N; Muraleetharan, K K; Dafalias, Y F: Herrmann, L R; Shinde, S B J Geotech Engng Div ASCE VII6. N9, Sept 1990, PI2911308 Response of the clay bed of the Beaufort Sea to excavation, construction of a sand island, and placement and filling of a caisson is modelled using 2-dimensional finite element analysis. The sea bed is characterised by the bounding surface model for cohesive soils, with parameters from similar soils tested in the laboratory and soil stress state from in situ measurements. Numerical predictions of pore pressures, stresses, and displacements during the staged construction are in good agreement with field measurements.
912342 Improvement of soils by vertical rigid piles, for shallow foundations (In French) Combarieu, O Rev Fr Geoteck N53, 1990, P33-44 Completion of work started in 1986 on improvement of soft soils of foundations by rigid vertical micropiles is described. Relatively simple methods have been developed to dimension the pile network, which is loaded via an intermediate surface fill by flexible rafts or rigid footings. Comparisons are made between design data and published applications of similar reinforcement to demonstrate its applicability.
912339 Behavior of vibro-driven piles in sand Vipulanandan, C: Wong, D; O'Neill, M W J Geotech Engng Div ASCE VII6. N8, Aug 1990, P!2111230
912343 Slide of a slope with foundations of an industrial building Uiichkin, G M Soil Meeh Found Engng 1/26, N6. Nov-Dec 1989, P239-242
An analytical study is presented for previously described model tests (ibid, V116, P! 190-1209). In these, relative density of the sand had a greater influence on driving rate and bearing capacity than other parameters investigated. Based on tests and analysis, several models are evaluated to predict bearing capacity, load-displacement curves, and nonlinear load transfer curves for the vibrodriven piles. The exponential and modified Ramberg-Osgood models predict behaviour in reasonable agreement with test results. Performance of vibrodriven and impact driven piles is compared.
The slope considered had a shallow gradient (0.06) and 0.2m of topsoil, 4.5m of dense moist clay, then 28m of similar clay containing thin sand interlayers. Monolithic block foundations were installed in 4.5m deep trenches. Heave of the trench bottom caused foundation displacement and slides occurred, resulting in cracks forming at the brow of the trench slope. Examination revealed slides occurred due to the sand interlayers acting as weakened planes in the soil mass. Displacements were a result of frost heave. Neither of these were foreseen in the initial site investigation and design stages.
© 1991 Pergamon Press plc. Reproduction not permitted RMMS 28 .~3--K
91234O Bearing capacity of expanded-base piles with compacted concrete shafts Neely, W J J Geoteeh Engng Div ASCE VI16, N9, Sept 1990, P13091324
Uncertainty associated with soil properties can arise from several sources. The primary uncertainty herein is the natural variability of the soil, which is included using the discrete three point approximation (3PA) of Rosenblueth. The uncertainty analysis is applied to performance of laterally loaded drilled piles. Observed behaviour and the deterministic solution based on mean values of material properties are seen to be bracketed by the predicted 3PA range of response.
A database of load test results on 71 uncased, expanded base pile in sands at 61 sites was assembled, to assist development of empirical design methods based on SPT N count. Both shaft and end resistance increase with depth and increasing N count. They appear to reach limiting values in loose soils at shaft length/diameter of about 12, but continue increasing at a decreasing rate in denser soils. A modification to traditional bearing capacity theory explains this scale effect as related to decrease in bearing capacity factor (a function of friction angle) with increasing depth or overburden pressure, hence point resistance increases with depth at a decreasing rate.
912337 Settlement analysis of socketed pile groups Chow, Y K; Chin, J T; Kog, Y C; Lee, S L J Geotech Engng Div ASCE VII6, N8, Aug 1990, P11711184 A numerical procedure is presented for settlement analysis of group piles penetrated through an upper soil layer to socket in bearing stratum of finite stiffness. Parametric analysis is used to examine influence of soil, pile, and bearing stratum properties on group performance. Graph data provided allow simple estimation of pile settlement under normal working loads. Applications to settlement of two structures supported on socketed pile groups are illustrated.
912338 Laboratory modeling of vibro-driven piles O'Neill, M W~ Vipulanandan, C, Wong, D J Geotech Engng Div ASCE VII6, N8, Aug 1990. P11901209 102mm diameter instrumented model piles were penetrated into sand in a pressure chamber by vibro-driving and impact. Influence of soil grain size and relative density, vibratory parameters, and restriking with impact on pile performance was studied. Maximum penetration rate was achieved at driving frequency 20Hz, regardless of soil parameters or other driving parameters. Relative density had greatest influence on penetration rate. Static and dynamic load-transfer curves are developed for vibratory driving and compared to those for impact. Impact driven piles have greater bearing capacity than vibration driven piles at 65% soil relative density, lower at 95% relative density.
912341 Foundation-response predictions below caisson-retained island Kaliakin, V N; Muraleetharan, K K; Dafalias, Y F: Herrmann, L R; Shinde, S B J Geotech Engng Div ASCE VII6. N9, Sept 1990, PI2911308 Response of the clay bed of the Beaufort Sea to excavation, construction of a sand island, and placement and filling of a caisson is modelled using 2-dimensional finite element analysis. The sea bed is characterised by the bounding surface model for cohesive soils, with parameters from similar soils tested in the laboratory and soil stress state from in situ measurements. Numerical predictions of pore pressures, stresses, and displacements during the staged construction are in good agreement with field measurements.
912342 Improvement of soils by vertical rigid piles, for shallow foundations (In French) Combarieu, O Rev Fr Geoteck N53, 1990, P33-44 Completion of work started in 1986 on improvement of soft soils of foundations by rigid vertical micropiles is described. Relatively simple methods have been developed to dimension the pile network, which is loaded via an intermediate surface fill by flexible rafts or rigid footings. Comparisons are made between design data and published applications of similar reinforcement to demonstrate its applicability.
912339 Behavior of vibro-driven piles in sand Vipulanandan, C: Wong, D; O'Neill, M W J Geotech Engng Div ASCE VII6. N8, Aug 1990, P!2111230
912343 Slide of a slope with foundations of an industrial building Uiichkin, G M Soil Meeh Found Engng 1/26, N6. Nov-Dec 1989, P239-242
An analytical study is presented for previously described model tests (ibid, V116, P! 190-1209). In these, relative density of the sand had a greater influence on driving rate and bearing capacity than other parameters investigated. Based on tests and analysis, several models are evaluated to predict bearing capacity, load-displacement curves, and nonlinear load transfer curves for the vibrodriven piles. The exponential and modified Ramberg-Osgood models predict behaviour in reasonable agreement with test results. Performance of vibrodriven and impact driven piles is compared.
The slope considered had a shallow gradient (0.06) and 0.2m of topsoil, 4.5m of dense moist clay, then 28m of similar clay containing thin sand interlayers. Monolithic block foundations were installed in 4.5m deep trenches. Heave of the trench bottom caused foundation displacement and slides occurred, resulting in cracks forming at the brow of the trench slope. Examination revealed slides occurred due to the sand interlayers acting as weakened planes in the soil mass. Displacements were a result of frost heave. Neither of these were foreseen in the initial site investigation and design stages.
© 1991 Pergamon Press plc. Reproduction not permitted RMMS 28 .~3--K