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The ultimate shaft frictional resistance mobilised by bored piles in over-consolidated clays and socketed into weak and weathered rock
SURFACE STRUCTURES:FOUNDATIONS uniform or irregular cyclic loading. The soil mass may be arbitrarily layered and the nonlinear pile response is represented by a s~n~le cyclic hyperbolic interface soil model. The method is used to analyze the response of model pile-group tests in soft clay under cyclic loading. In addition, a repeated monotonic loading on a full-scale pilegroup field test in stiff overconsolidated clay is analyzed. -from Author 943270 I m p e d a n c e functions of piles in inhomogeneous media H. Vazixi & Y. Han, Journal of Geotechnical Engineering - ASCE, 119(9), 1993, pp 1414-1430. A new model is presented for characterizing the response of soils within the boundary zone around piles. The proposed concept provides for a continuous variation of soil properties with smooth transition into the outer zone; these operties alleviate the wave reflections from the interface tween the two media. With this model the impedances of composite layers do not show the oscillations mat axe generally observed with the other boundary zone models that take account of the soil mass. The developed impedance functions are used in the dynamic analysis of a field problem involving vertical vibration of a single pile. -from Authors 943271 Pipelines and laterally loaded piles in elastoplastic medium B. Rajani & N. Morgenstern, Journal of Geotechnical Engineering - ASCE, 119(9), 1993, pp 1431-1448. The uplift behavior of a shallow pipeline embedded in an elastoplastic medium is examined. An analytical solution for a beam on elastoplastic foundation is developed and a characteristic nondLmensional load-displacement and stress-displacement relationships are presented. An approximate three-dimensional (3D) solution is proposed that accounts for embedment and breakaway condition behind the pipeline. A comparison of these results with those obtained by 3D finite-element analysis indicates that the simplified solution of a beam on elastoplastic foundation is a practical alternative for analyzing the uplift behavior of shallow pipelines. -from Authors 943272 Settlement of pile groups - practical a p p r o a c h C. Y. Lee, Journal of Geotechnical Engineering - ASCE, 119(9), 1993, pp 1449-1461. A simple and practical approach is presented for the analysis of settlement of large pile groups embedded in an isotropic elastic half-space wlth adequate accuracy but without the expense of a complete rigorous analysis. The approach is based on the superposition of the interaction factors between piles within a group. An approximate closed-form analytical model is suggested to evaluate these interaction factors in homogeneous and nee.homogeneous soils. The values of the interaction factors comPhUted by the analytical model agree reasonably well with ose by the more rigorous boundary element approach. -from Author 943273
Simplified a p p r o a c h for pile and foundation
interaction analysis
Keming Sun & J. A. Pires, Journal of Geotechnical Engineering- ASCE, 119(9), 1993, pp 1462-1479. A simple approach is described for the analysis of soil-pile interactions under static and dynamic lateral Ioadings. The method uses variational calculus to obtain the governing differential equations of motion for the soil-pl]e system under a harmonic concentrated load at the pile head with intensity Po and frequency co. The solutions are based on a semianalytical and seminumerical approach, and are brought to a form that makes it possible to predict the dynamic.displacements, stiffness, and damping for different soils and end conditions of the pile. Two cases are investigated: I) A pile clamped to a rigid bottom underlying an elastic soil layer; and 2) a floating pile in a elastic half-space. -from Authors 943274
A p p r o x i m a t e G r e e n ' s function for surface
foundations
J. W. Meek & J. P. Wolf, Journal of Geotechnical Engineering - ASCE, 119(10), 1993, pp 1499-1514.
155A
In a strength-of-materials approach to foundation dynamics, approximate Green's functions are employed in lieu of rigorous fundamental solutions. For a vertical _point load on the elastic half-space, the form of the Green s function may be deduced via noumathematical physical reasoning, then calibrated with a few constants taken from rigorous solutions. By superposing point loads, approximate Green's functions are constructed for a ring, then a disk. Finally, arbitrarily shaped foundations are treated as an assemblage of subdisks. As an example, rectangular foundations with various slenderness ratios are analyzed. -from Authors 943275 Pile groups under negative skin friction C . Y . Lee, Journal of Geotechnical Engineering - ASCE, 119(10), 1993, pp 1587-1600. This paper describes a simplified hybrid load-transfer approach for analyzing the response o f pile groups under negative skin friction. The interaction between piles in a group, bearing on a stiffer stratum is considered using a modified form of Mindlin's analytical point-load solution. The consolidation settlement is estimated by using Terzaghi's one-dimensional consolidation theory. The linear elastic solutions computed by the present approach are in good agreement with those by the more rigorous continuum approaches. The behavior of two field pile tests and a test on a model nine-pile group subjected to negative skin friction predicted by the present nonlinear approach agrees favorably with the measured results. -from Author The ultimate shaft frictional resistance mobilised by bored piles in over-consolidated clays and socketed into weak and weathered rock 943276
P. Hooley & S. R. L. Brooks, in: The engineering geology of weak rock. Proc. conference, Leeds, 1990, ed J.C. Cripps & others, (Balkema; Engineering Geology Special Publication, 8), 1993, pp 447-455. Data from pile tests, carried out to failure to measure the ultimate shaft frictional resistance mobilized in rock sockets are presented. These tests comprised tension tests, compression tests on piles with voided toes and model pile tests. On the basis of these results, correlations have been proposed, relating the ultimate shah frictional resistance to the unconfined compressive strength of the rock. Examination of the results of a number of p i l e tests carried out in weak, highly weathered rocks indicates inaccurate estimates of frictional resistance. In order topermit the design of socketed piles, where the benefits of preliminary pile tests are not available, this paper seeks to suggest a lower bound correlation between ultimate shah frictional resistance and unconfined compressive strength for use in the preliminary design of boredpiles. -from Authors 943277
Soil-pile interaction during the passage of
Rayleigh waves: an analytical solution N. Makris, Earthquake Engineering & Structural Dynamics, 23(2), 1994, pp 153-167. A simple analytical solution is presented to calculate the single-pile response when excited by the passage of Rayleigh seismic waves. It is shown that in vecdcal motion, the differences between pile and soil displacements are far more significant than in horizontal motion, and therefore, further work is needed to investigate the importance of pile-soil-pile interaction (group effects), because of the vertical component of Rayleigh seismic waves. -from Author Dynamic behaviour of pile foundations in homogeneous and non-homogeneous media
943278
K. Miura, A. M. Kaynia, K. Masuda, E. Kitamura & Y. Sere, Earthquake Engineering & Structural Dynamics, 23(2), 1994, pp 183-192. A three-dimensional formulation based on Green's functions of cylindrical loads in layered semi-infinite media is employed to investigate the dynamic behaviour of piles in homo~.eneous and non-homogeneous half spaces. The pilesoil-pile interaction taking place in pile groups is incorporated in the model. The results include the dynamic stiffness and damping of single piles as well as those of representative 2 x 2 and 4 x 4 squarepile groups in the soil media considered in this study. I n addition, the distribution
Simplified a p p r o a c h for pile and foundation
interaction analysis
Keming Sun & J. A. Pires, Journal of Geotechnical Engineering- ASCE, 119(9), 1993, pp 1462-1479. A simple approach is described for the analysis of soil-pile interactions under static and dynamic lateral Ioadings. The method uses variational calculus to obtain the governing differential equations of motion for the soil-pl]e system under a harmonic concentrated load at the pile head with intensity Po and frequency co. The solutions are based on a semianalytical and seminumerical approach, and are brought to a form that makes it possible to predict the dynamic.displacements, stiffness, and damping for different soils and end conditions of the pile. Two cases are investigated: I) A pile clamped to a rigid bottom underlying an elastic soil layer; and 2) a floating pile in a elastic half-space. -from Authors 943274
A p p r o x i m a t e G r e e n ' s function for surface
foundations
J. W. Meek & J. P. Wolf, Journal of Geotechnical Engineering - ASCE, 119(10), 1993, pp 1499-1514.
155A
In a strength-of-materials approach to foundation dynamics, approximate Green's functions are employed in lieu of rigorous fundamental solutions. For a vertical _point load on the elastic half-space, the form of the Green s function may be deduced via noumathematical physical reasoning, then calibrated with a few constants taken from rigorous solutions. By superposing point loads, approximate Green's functions are constructed for a ring, then a disk. Finally, arbitrarily shaped foundations are treated as an assemblage of subdisks. As an example, rectangular foundations with various slenderness ratios are analyzed. -from Authors 943275 Pile groups under negative skin friction C . Y . Lee, Journal of Geotechnical Engineering - ASCE, 119(10), 1993, pp 1587-1600. This paper describes a simplified hybrid load-transfer approach for analyzing the response o f pile groups under negative skin friction. The interaction between piles in a group, bearing on a stiffer stratum is considered using a modified form of Mindlin's analytical point-load solution. The consolidation settlement is estimated by using Terzaghi's one-dimensional consolidation theory. The linear elastic solutions computed by the present approach are in good agreement with those by the more rigorous continuum approaches. The behavior of two field pile tests and a test on a model nine-pile group subjected to negative skin friction predicted by the present nonlinear approach agrees favorably with the measured results. -from Author The ultimate shaft frictional resistance mobilised by bored piles in over-consolidated clays and socketed into weak and weathered rock 943276
P. Hooley & S. R. L. Brooks, in: The engineering geology of weak rock. Proc. conference, Leeds, 1990, ed J.C. Cripps & others, (Balkema; Engineering Geology Special Publication, 8), 1993, pp 447-455. Data from pile tests, carried out to failure to measure the ultimate shaft frictional resistance mobilized in rock sockets are presented. These tests comprised tension tests, compression tests on piles with voided toes and model pile tests. On the basis of these results, correlations have been proposed, relating the ultimate shah frictional resistance to the unconfined compressive strength of the rock. Examination of the results of a number of p i l e tests carried out in weak, highly weathered rocks indicates inaccurate estimates of frictional resistance. In order topermit the design of socketed piles, where the benefits of preliminary pile tests are not available, this paper seeks to suggest a lower bound correlation between ultimate shah frictional resistance and unconfined compressive strength for use in the preliminary design of boredpiles. -from Authors 943277
Soil-pile interaction during the passage of
Rayleigh waves: an analytical solution N. Makris, Earthquake Engineering & Structural Dynamics, 23(2), 1994, pp 153-167. A simple analytical solution is presented to calculate the single-pile response when excited by the passage of Rayleigh seismic waves. It is shown that in vecdcal motion, the differences between pile and soil displacements are far more significant than in horizontal motion, and therefore, further work is needed to investigate the importance of pile-soil-pile interaction (group effects), because of the vertical component of Rayleigh seismic waves. -from Author Dynamic behaviour of pile foundations in homogeneous and non-homogeneous media
943278
K. Miura, A. M. Kaynia, K. Masuda, E. Kitamura & Y. Sere, Earthquake Engineering & Structural Dynamics, 23(2), 1994, pp 183-192. A three-dimensional formulation based on Green's functions of cylindrical loads in layered semi-infinite media is employed to investigate the dynamic behaviour of piles in homo~.eneous and non-homogeneous half spaces. The pilesoil-pile interaction taking place in pile groups is incorporated in the model. The results include the dynamic stiffness and damping of single piles as well as those of representative 2 x 2 and 4 x 4 squarepile groups in the soil media considered in this study. I n addition, the distribution