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Nonlinear vibration of pile groups under lateral loading. Note
197A 933445 Stabflisation of a landslide with submerged motor-driven pumps Olcese, A; Vescovo, C; Boni, S; Giusti, G
Proc Conference on Slope Stability Esgineering: Deve~pmeats and Applications, Isle of Wight, 15-18 April 1991 P321-326. Publ London: Thomas Telford, 1991 A gas pipeline near Campegii (Genoa, Italy) crosses an old landslide. Prior to laying the pipes, a stratigraphic profile was obtained, hydrology investigated, and geotechnical properties of the materials involved measured. Slope stability analysis was carried out and it was decided to lower the water table to improve stability. Small diameter wells with submerged pumps and drainage trenches were installed. Monitoring data from piezometers, inclinometers, and strain gauges on the pipeline itself are presented, which demonstrate the stability achieved.
933449 Sei,mie response of mulfl~ehored retaining walls Siller, T J; Frawley, D D
J Geotech Engng Die ASC£ V118, Nll, Nov 1992, P17871803 Finite element analysis of a multianchored retaining wall under dynamic loading is presented. Effects of anchor stiffness, inclination, and vertical spacing (single to four-anchor wall) on maximum and permanent horizontal wall displacements and maximum anchor load are examined. Effects of input wavelength on response were also studied. Design recommendations are for numerous low stiffness anchors rather than few high stiffness anchors, and a stiffness value greater than that for static loading should be adopted.
Influence of dynamic loads
933450 Design of tied-back walls for seismic loading Siller, T J; Dolly, M O
See also: 933176
J Geotech Engng Die ASCE Vl18, Nll, Nov 1992, P18041821
933446 Nonlinear vibration of pile groups under lateral loading. Note Vaziri, H H; Han, Y
Can Geotech J V29, Nd, Aug 1992, P702-710 Groups of 6 (3x2) full size cast-in-situ piles have been subject to various levels of harmonic excitation along and across the plane composed of 3 piles. Measured response is compared to that predicted using the dynamic interaction factors approach, with a boundary concept introduced to account for yielding of the soil around the piles. Rocking stiffness is significantly influenced by the number of piles in the direction of excitation, horizontal stiffness virtually unaffected. Stiffness and damping of the pile group reduce with increasing excitation intensity. 933447 F_ABeient time-domain soil-structure interaction analysis based on the dynamic stiffness of an unbounded soil Hayashi, Y; Takahashi, I
Finite element simulation of the seismic behaviour of static and seismic tiedback retaining wall designs is presented. Two designs are considered: one assuming active earth pressure, resulting in a single anchor design, and one assuming a rectangular apparent-pressure diagram, giving a two-anchor design. These designs are modified using the Mononobe-Okabe method to account for seismic loading. The two-anchor static design suffers less displacement than either static or seismic single anchor designs and is as good as the two-anchor seismic design at accelerations less than 0.2g. Increasing embedment depth above the M-O calculated value provides no benefit in limiting displacements above the dredgeline.
933451 Vertical radiation damping for a circular footing resting on a simple layered half-space Navarre, C
Earthq Engng Struct Dynam V21, N9, Sept 1992, P787-796
Soil Dynam Earthq E n g q VI1, N5, 1992, P249-253
An approximate (preliminary) method and a rigorous (detailed) method for time-domain soil-structure interaction analysis are presented. They use soil stiffness values obtained in the limited frequency range and are based on the approximation that the first few terms of the Fourier or Taylor expansion of a frequency-dependent function are used. The difference lies in the number of coefficients of each series and the manner in which the coefficients can be determined. They are demonstrated for a soil-structure system with a complex soil profile under the foundation.
A simplified approximate analysis is presented for the case of a rigid circular foundation subject of vertical harmonic loading of fixed amplitude. The footing rests on an elastic layer of constant thickness over an elastic half space. The conventional damping ratio is evaluated as a function of layer thickness, foundation radius and Poisson's ratio, and layer and half space mechanical properties. Results are presented graphically as a practical design aid.
933448 Axisymn~tric infinite elements for soil-structure interaction
am~ym Yang, S C; Yun, C B
£ngmg Struct V14, N6, Nov 1992, P361-370 A dynamic infinite element which can deal efficiently with multiple wave components is presented, which allows discretization of the far field in unbounded soil media. An efficient numerical scheme is devised for constructing the element characteristic matrices of the infinite elements using the GaussLaguerre quadrature. It is illustrated in calculations of the impedance of circular footings on elastic and on layered half spaces.
933452 Application of reflection and frequency methods in nondestructive pile foundation inspection Li Piwu
Proc 3rd Imermuiomd Symposhtm o n Field Mensuremeats in Geomeclumics, Osio, 9-11 September 1991 V1, P43-51. Publ Rotterdam: A A Balkema, 1991 Techniques based on analysis of results from use of an exploration seismograph and a steady state vibration source to determine the type and location of defects in piles are presented. Basic theory is outlined and limitations at various depth ranges discussed. Methods to evaluate the bearing capacity of single piles from in situ measurements of dynamic stiffness are also presented.
© 1993 Pergamon Press Ltd. Reproduction not permitted
Proc Conference on Slope Stability Esgineering: Deve~pmeats and Applications, Isle of Wight, 15-18 April 1991 P321-326. Publ London: Thomas Telford, 1991 A gas pipeline near Campegii (Genoa, Italy) crosses an old landslide. Prior to laying the pipes, a stratigraphic profile was obtained, hydrology investigated, and geotechnical properties of the materials involved measured. Slope stability analysis was carried out and it was decided to lower the water table to improve stability. Small diameter wells with submerged pumps and drainage trenches were installed. Monitoring data from piezometers, inclinometers, and strain gauges on the pipeline itself are presented, which demonstrate the stability achieved.
933449 Sei,mie response of mulfl~ehored retaining walls Siller, T J; Frawley, D D
J Geotech Engng Die ASC£ V118, Nll, Nov 1992, P17871803 Finite element analysis of a multianchored retaining wall under dynamic loading is presented. Effects of anchor stiffness, inclination, and vertical spacing (single to four-anchor wall) on maximum and permanent horizontal wall displacements and maximum anchor load are examined. Effects of input wavelength on response were also studied. Design recommendations are for numerous low stiffness anchors rather than few high stiffness anchors, and a stiffness value greater than that for static loading should be adopted.
Influence of dynamic loads
933450 Design of tied-back walls for seismic loading Siller, T J; Dolly, M O
See also: 933176
J Geotech Engng Die ASCE Vl18, Nll, Nov 1992, P18041821
933446 Nonlinear vibration of pile groups under lateral loading. Note Vaziri, H H; Han, Y
Can Geotech J V29, Nd, Aug 1992, P702-710 Groups of 6 (3x2) full size cast-in-situ piles have been subject to various levels of harmonic excitation along and across the plane composed of 3 piles. Measured response is compared to that predicted using the dynamic interaction factors approach, with a boundary concept introduced to account for yielding of the soil around the piles. Rocking stiffness is significantly influenced by the number of piles in the direction of excitation, horizontal stiffness virtually unaffected. Stiffness and damping of the pile group reduce with increasing excitation intensity. 933447 F_ABeient time-domain soil-structure interaction analysis based on the dynamic stiffness of an unbounded soil Hayashi, Y; Takahashi, I
Finite element simulation of the seismic behaviour of static and seismic tiedback retaining wall designs is presented. Two designs are considered: one assuming active earth pressure, resulting in a single anchor design, and one assuming a rectangular apparent-pressure diagram, giving a two-anchor design. These designs are modified using the Mononobe-Okabe method to account for seismic loading. The two-anchor static design suffers less displacement than either static or seismic single anchor designs and is as good as the two-anchor seismic design at accelerations less than 0.2g. Increasing embedment depth above the M-O calculated value provides no benefit in limiting displacements above the dredgeline.
933451 Vertical radiation damping for a circular footing resting on a simple layered half-space Navarre, C
Earthq Engng Struct Dynam V21, N9, Sept 1992, P787-796
Soil Dynam Earthq E n g q VI1, N5, 1992, P249-253
An approximate (preliminary) method and a rigorous (detailed) method for time-domain soil-structure interaction analysis are presented. They use soil stiffness values obtained in the limited frequency range and are based on the approximation that the first few terms of the Fourier or Taylor expansion of a frequency-dependent function are used. The difference lies in the number of coefficients of each series and the manner in which the coefficients can be determined. They are demonstrated for a soil-structure system with a complex soil profile under the foundation.
A simplified approximate analysis is presented for the case of a rigid circular foundation subject of vertical harmonic loading of fixed amplitude. The footing rests on an elastic layer of constant thickness over an elastic half space. The conventional damping ratio is evaluated as a function of layer thickness, foundation radius and Poisson's ratio, and layer and half space mechanical properties. Results are presented graphically as a practical design aid.
933448 Axisymn~tric infinite elements for soil-structure interaction
am~ym Yang, S C; Yun, C B
£ngmg Struct V14, N6, Nov 1992, P361-370 A dynamic infinite element which can deal efficiently with multiple wave components is presented, which allows discretization of the far field in unbounded soil media. An efficient numerical scheme is devised for constructing the element characteristic matrices of the infinite elements using the GaussLaguerre quadrature. It is illustrated in calculations of the impedance of circular footings on elastic and on layered half spaces.
933452 Application of reflection and frequency methods in nondestructive pile foundation inspection Li Piwu
Proc 3rd Imermuiomd Symposhtm o n Field Mensuremeats in Geomeclumics, Osio, 9-11 September 1991 V1, P43-51. Publ Rotterdam: A A Balkema, 1991 Techniques based on analysis of results from use of an exploration seismograph and a steady state vibration source to determine the type and location of defects in piles are presented. Basic theory is outlined and limitations at various depth ranges discussed. Methods to evaluate the bearing capacity of single piles from in situ measurements of dynamic stiffness are also presented.
© 1993 Pergamon Press Ltd. Reproduction not permitted