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Field study of moisture effects on slab movements
!IOA
785139 SLIPPING THEN STICKING Cor~mlt Er~r, V41, NI, Jan 1977, P39-&I Describes the al~lication of electro-osmosis in piling, w h ~ e b y the ~rou~'s resistance to pile drivimg in certain soils can be halved without affecting the load bearimg ability of either ground or pile after completion of driving. In fine soils such as clays, a hydraulic gradier~ of more than 1000 m h e a ~ m can be obtained. 785140 SETTLII~ DOWN CCMFORTABLY Corm~It Emgr, V~I, NI, Jan 1977, P~I-43 A brief review of the symposit~n 'Piling '76' held in November 1976, at which the current CIEIA research l~ogramme was discussed. Topics covered are: cast-in-place concrete piles, use of bentonite suspensions in piling, amd a study of moderately loaded four~ations in LOndon clay to determine the atruct~ral loads carried by piles. This study suggests %hat there may be no need for piles in the type of construction described. 78~i~I F ~ STUDY OF M O I S ~ EFFECTS ON SLAB M O V ~ N T S Tucker, R L; Pock, A R J Geotech Emgmg Div, ASCE, V104, EUgI%, April
1978, I~03-~i~ A study is re~orted of 69 residential slabs located in an area of expansive clay. The slabs had experienced significant differer~ial vertical movements. Differential vertical mov~me~s are shown to correlate with differences in moisture contents from the centre to the corne~s of the slabs. Trees planted near the houses are shown to have majOr influences u~on slab behaviour. The tree root systems absorbed moisture from the soil causing subsequent drying under the slab edges.
7851LI-2 UNSHEATHED
EXCAVATION IN COHESIVE SOILS. TECHNICAL NOTE War~, W L; Salmassian, K J Geotech Engmg Div, ASCE, V104, NGT4, A ~ i l
1978, I%93-h-96 Relates to the stability of soils between unsheathed piles. 78~143 LIMITING EQUILIBRIUM ANALYSIS OF STRIP FOOTINGS Cralg~ R F; Pariti, L N M J Geotech Emgr~ Div, ASCE, V104, NGT3, March 1978, P357-368 A computer-o~ient~ method of analysis, using the limiting equilibrit~ principle amd satisfying all the comditio~ of equilibrium, is presented for the determimation of the bearing capacity of tunifQc~mly loaded shallow s~rip footings. The soils mass above a potential failure surface is divided into a rs~mber of vertical slices ar~ %he basic equations of equilibri~ are derived in te~ms of effective stresses. A r ~ b e r of examples are solved involving differez~ types of soils, deph~ widT~ ratios, and Positions of ground-water level. Comparison is made with the results from other theories of bearing capacity.
785144
SEISMIC RESPONSE DUE TO TRAVELLING SHEAR WAVE INCLUDING SOIL-S~UCTUHE INTERACTION WITH BASEMAT UPLIFT Wolf~ J P Int J Earthq EngDg S t r ~ Dynam, VS, N~, OctDec i ~ , P337-93 A theoretical studcF of the translational ar~l
torsional excitations of a circular foumdation
mat caused by the passage of an S-wave. A soilstructure interaction model is developed,~ including a generallsed procedure to accour~ for partial separation of the mat amd for slipping. As an example, %he dynamic response of an axesymmetric nuclear reactor building is determined. 785145 RESISTANCE OF SOIL TO A HORIZONTALLY VIBRATI~K~ PILE Nogaml, T; Novak, M In% J E a r ~ Emgmg Struct Dyr~, V5, N3, JttlySept 1977, P249-261 The resistance of a soil layer to steady hOrizontal vibration of an elastic pile ~s thecretically investigated. The pile is a s s ~ to be vertical a~d of clrc~lar cross-section. The soil is modelled as a llnear viscoelastic layer with hysteretic material damping. A closed form solution is obtained for the resistance of the soll l a ~ to the motion. This resistance depends on shear modulus of soil, frequmncy, pile slemderness, material damping and Poisson's ratio. A param~i~ic s t t ~ of the effect of these parameters is incl~ded. The soil layer resistamce is expressed in a form which can be used directly in the sel~ion of %he soil-pile ir/beraction problem which is treated in a subsequent paper. The apl~oach also applies for rigid deeply embedded footings. Auth. 785146 SOIL-PILE INI~ZRACTION IN HORiZOI~AL VIBRATION Novak, M; Nogaml, T Int J E a z ~ E r ~ Struct Dynsm, VS, N3, JulySept 1977, P26B-281 The modification of pile stiffness and the generation of damping due to er2rgy radiation ar~ dissipation in the soil are analysed and the response of the pile to horizontal loads and moments in the vertical plane is theoretically investigated. This study is based on the definition of the resistance of the soil layer to the pile motion presented in a preceding paper. 785147 CONTAC~f SI~SSES AED GROUND MORION GENERATED BY SOIL S T R U L ~ INTERACTION Wong, H L; Luco, J E; Trif~Anac, M D Int J Esrthq Er~ng Struct Dyn~m, V5, N1, JanMarch 1977, Fo7-79 ~udies the dynamic contact stresses that the foundation of a nine-storey reinforced concrete building exerts on the soil durir~ forced vibration tests. The effects of the flexibility of the founlation on %he contact stress distribution ani on the f o r c e - d i s p l a c ~ relationship for the founlstion have been e x ~ n e d i n order to test several simplifying a s ~ l ~ i o n s commonly used in soil-atructure interaction studies. Comparisons of calculated amd ob~ea=ved ground displacements are also made. 785148 METHODS OF FOI~41NG HOLES FOR CAST-IN-PLAC~ PILES Wl~OLWf SOIL EXCAVATION Ermoshkln, P M Soil Mech Found Engng, VI3, N4, July-Aug 1976, P252-256 Discusses the use of cable tool rigs for drilling holes l~ior to installing cast-in-place piles. Tests were carried out using driving or boring to form the holes and rsnmdng in layers or no ramming to concrete them. Another system for installing cast-in-place piles, using a vlbroformer, is also described. Both method~ are
785139 SLIPPING THEN STICKING Cor~mlt Er~r, V41, NI, Jan 1977, P39-&I Describes the al~lication of electro-osmosis in piling, w h ~ e b y the ~rou~'s resistance to pile drivimg in certain soils can be halved without affecting the load bearimg ability of either ground or pile after completion of driving. In fine soils such as clays, a hydraulic gradier~ of more than 1000 m h e a ~ m can be obtained. 785140 SETTLII~ DOWN CCMFORTABLY Corm~It Emgr, V~I, NI, Jan 1977, P~I-43 A brief review of the symposit~n 'Piling '76' held in November 1976, at which the current CIEIA research l~ogramme was discussed. Topics covered are: cast-in-place concrete piles, use of bentonite suspensions in piling, amd a study of moderately loaded four~ations in LOndon clay to determine the atruct~ral loads carried by piles. This study suggests %hat there may be no need for piles in the type of construction described. 78~i~I F ~ STUDY OF M O I S ~ EFFECTS ON SLAB M O V ~ N T S Tucker, R L; Pock, A R J Geotech Emgmg Div, ASCE, V104, EUgI%, April
1978, I~03-~i~ A study is re~orted of 69 residential slabs located in an area of expansive clay. The slabs had experienced significant differer~ial vertical movements. Differential vertical mov~me~s are shown to correlate with differences in moisture contents from the centre to the corne~s of the slabs. Trees planted near the houses are shown to have majOr influences u~on slab behaviour. The tree root systems absorbed moisture from the soil causing subsequent drying under the slab edges.
7851LI-2 UNSHEATHED
EXCAVATION IN COHESIVE SOILS. TECHNICAL NOTE War~, W L; Salmassian, K J Geotech Engmg Div, ASCE, V104, NGT4, A ~ i l
1978, I%93-h-96 Relates to the stability of soils between unsheathed piles. 78~143 LIMITING EQUILIBRIUM ANALYSIS OF STRIP FOOTINGS Cralg~ R F; Pariti, L N M J Geotech Emgr~ Div, ASCE, V104, NGT3, March 1978, P357-368 A computer-o~ient~ method of analysis, using the limiting equilibrit~ principle amd satisfying all the comditio~ of equilibrium, is presented for the determimation of the bearing capacity of tunifQc~mly loaded shallow s~rip footings. The soils mass above a potential failure surface is divided into a rs~mber of vertical slices ar~ %he basic equations of equilibri~ are derived in te~ms of effective stresses. A r ~ b e r of examples are solved involving differez~ types of soils, deph~ widT~ ratios, and Positions of ground-water level. Comparison is made with the results from other theories of bearing capacity.
785144
SEISMIC RESPONSE DUE TO TRAVELLING SHEAR WAVE INCLUDING SOIL-S~UCTUHE INTERACTION WITH BASEMAT UPLIFT Wolf~ J P Int J Earthq EngDg S t r ~ Dynam, VS, N~, OctDec i ~ , P337-93 A theoretical studcF of the translational ar~l
torsional excitations of a circular foumdation
mat caused by the passage of an S-wave. A soilstructure interaction model is developed,~ including a generallsed procedure to accour~ for partial separation of the mat amd for slipping. As an example, %he dynamic response of an axesymmetric nuclear reactor building is determined. 785145 RESISTANCE OF SOIL TO A HORIZONTALLY VIBRATI~K~ PILE Nogaml, T; Novak, M In% J E a r ~ Emgmg Struct Dyr~, V5, N3, JttlySept 1977, P249-261 The resistance of a soil layer to steady hOrizontal vibration of an elastic pile ~s thecretically investigated. The pile is a s s ~ to be vertical a~d of clrc~lar cross-section. The soil is modelled as a llnear viscoelastic layer with hysteretic material damping. A closed form solution is obtained for the resistance of the soll l a ~ to the motion. This resistance depends on shear modulus of soil, frequmncy, pile slemderness, material damping and Poisson's ratio. A param~i~ic s t t ~ of the effect of these parameters is incl~ded. The soil layer resistamce is expressed in a form which can be used directly in the sel~ion of %he soil-pile ir/beraction problem which is treated in a subsequent paper. The apl~oach also applies for rigid deeply embedded footings. Auth. 785146 SOIL-PILE INI~ZRACTION IN HORiZOI~AL VIBRATION Novak, M; Nogaml, T Int J E a z ~ E r ~ Struct Dynsm, VS, N3, JulySept 1977, P26B-281 The modification of pile stiffness and the generation of damping due to er2rgy radiation ar~ dissipation in the soil are analysed and the response of the pile to horizontal loads and moments in the vertical plane is theoretically investigated. This study is based on the definition of the resistance of the soil layer to the pile motion presented in a preceding paper. 785147 CONTAC~f SI~SSES AED GROUND MORION GENERATED BY SOIL S T R U L ~ INTERACTION Wong, H L; Luco, J E; Trif~Anac, M D Int J Esrthq Er~ng Struct Dyn~m, V5, N1, JanMarch 1977, Fo7-79 ~udies the dynamic contact stresses that the foundation of a nine-storey reinforced concrete building exerts on the soil durir~ forced vibration tests. The effects of the flexibility of the founlation on %he contact stress distribution ani on the f o r c e - d i s p l a c ~ relationship for the founlstion have been e x ~ n e d i n order to test several simplifying a s ~ l ~ i o n s commonly used in soil-atructure interaction studies. Comparisons of calculated amd ob~ea=ved ground displacements are also made. 785148 METHODS OF FOI~41NG HOLES FOR CAST-IN-PLAC~ PILES Wl~OLWf SOIL EXCAVATION Ermoshkln, P M Soil Mech Found Engng, VI3, N4, July-Aug 1976, P252-256 Discusses the use of cable tool rigs for drilling holes l~ior to installing cast-in-place piles. Tests were carried out using driving or boring to form the holes and rsnmdng in layers or no ramming to concrete them. Another system for installing cast-in-place piles, using a vlbroformer, is also described. Both method~ are