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Postdensification penetration resistance of clean sands
24A Mitchell's surface suction function, z can be determined using easily measured parameters; Lm is given as z-D, where D is depth of foundation below ground surface. Data required to evaluate z and Lm were obtained during an 18 month study of airport pavements on expansive soils. 911184 Postdonsiflcation penetration resistance of clean sands Mesri. G; Feng. T W; Benak. J M J Geoteck Eugng Die ASCE V116, N7, July 1990, P1095-
1115 Laboratory and field evidence shows significant increase with time in dynamic shear modulus and penetration resistance of sands after dynamic densification. A possible mechanism for this in clean sands is continued rearrangement of particles during secondary compression. Frictional resistance to deformation develops with gradual increase in interlocking and more efficient particle packing. Empirical relations are proposed to predict postprimary consolidation shear modulus and postdensification cone penetration resistance. These relations may be used to extrapolate measurements taken immediately after ground modification. 911185 Variability in compaction control Noorany, I
J Geoteck Engug Die ASCE VII6, N7, July 1990, Pl1321136 Multiple runs of field density tests were made at three structural fills by nine engineering firms. Each site had been approved as having met 90% relative compaction. All tests were conducted at the same time and elevation and in close proximity to each other. Scatter in results as % of mean value was respectively 17, 15, and 26% for uniform silty sand, silty clay, and gravelly to cobbly fills. This is greater than the variability generally found for embankment dams. Need to improve standards of practice for structural fills and shortcomings of the test procedures are discussed. 911186 New oedometer with splitted ring for the measurement of lateral stress Senneset, K
Proc 12th International Conference on Soil Mechanics and Foundation Engineering, Rio de Jneiro, 13-18 August 1989 VI, P115-118. Publ Rotterdam: A A Balkema, 1989 An oedometer with a 3-section ring has been used to investigate the relation between horizontal and vertical stresses in soil samples under consolidation. The sections may be adjusted to clamp the soil at a set contact pressure, and controlled lateral deformation is permissable. Horizontal stresses are measured by LVDTs in the ring sections. Results are presented for a Glava clay from Norway. 911187 Pore pressure behaviour of soft clay Wei, R L; Sun, B; Wang, N X
Proc 12th International Conference on Soil Mechanics and Foundation Eugineeriug, Rio de Janeiro, 13-18 August 1989 VI, P139-142. Publ Rotterdam: A A Balkema. 1989 Undrained shear tests were carried out on remoulded soft clay under a variety of stress paths in triaxial, plane strain, and hollow cylinder apparatuses. Results show normally consolidated clay is contractive in these tests, which behaviour cannot be described in many soil models. A new constitutive model for clays is developed on the basis of the experimental data. Case histories of consolidation of foundations for a tank and a
sea wall are analysed using the proposed model and those of Duncan and Chang, and of Wei (1981). Results are compared and discussed. 911188 Interpretation of pre~arem~er test for settlement prediction (In French) Biarez. J; Cambou. B; Bozetto. P; Haghgou. M; Bouhanga. A; Garcia, L A
Proc 12tb International Conference on Soil Mechanics and Fomulation Engineering, Rio de Janeiro, 13-18 August 1989 VI, P185-186. Publ Rotterdam: A A Balkema. 1989 Results of measurements of displacements beneath a surcharge fill are used to test several methods of settlement prediction. A method is proposed for calculation of settlements on the basis of pressuremeter test results which uses the hyperbolic constitutive model of Duncan et al (1980) with some modification of parameters. 911189 Characteristics of expansive soil in Hefei, China Fan. J S; Yang. C B
Proc International Conference on Engineering Problems of Regiomd Soils, k i j u g , !1-15 August 1988 P572-575. Publ Beifing: International Academic Publishers, 1989 The geotechnical properties of expansive clays from the region between the Yangtze and Yellow rivers have been examined. Mineralogical and chemical composition, swelling and shrinkage, physical properties, stress strain behaviour and overconsolidation have been studied. The soils have low water content, high liquid limit, and dense textures, and high overconsolidation ratios. Net shaped fissures resulting from cyclic swelling-shrinkage are found in the field. Slope failures are common in cut slopes and hydraulicstructures. 911190 Three dimensional model for expansive soil on wetting-drying Li, X Y; Li, X W
Proc International Conference on Engineering Problems of Regional Soils, Bei~ug, 11-15 August 1988 P610-613. Publ Beifing: International Academic Publishers, 1989 A three-dimensional model for swelling-shrinkage of a linear elastic soil is presented. An isothermal model assuming basic independent variables strain tensor and water content is postulated. A non-isothermal model including temperature and temperature gradient as additional independent variables can be developed from this. An attempt is made to correlate parameters of the model with those used in current engineering practice. The model is applied to a soil layer subject to evapotranspiration and to the problem of earth pressure behind a retaining wall. 911191 Experimental research of expansive soils used for dam construction Liu, L D
Proc International Confereuce on Engineering Problems of Regional Soils, Beifi'q, 11-15 August 1988 P621-624. Publ Beijing: International Academic Publishers, 1989 The characteristics of expansive soils of the Sichuan region of China are described, including mineralogy, expansivity, plasticity and liquid limit. Softening on expansion and cracking on shrinkage must be taken into account when they are used in hydraulic structures. Several case studies of their use in cores of rock-earth fill dams are presented. They are mixed with non-expansive soils, and placed at optimum moisture content and compacted using heavy rollers to ensure high shear strength with low permeability, expansion and shrinkage.
© 1991 Pergamon Press pic. Reproduction not permitted
1115 Laboratory and field evidence shows significant increase with time in dynamic shear modulus and penetration resistance of sands after dynamic densification. A possible mechanism for this in clean sands is continued rearrangement of particles during secondary compression. Frictional resistance to deformation develops with gradual increase in interlocking and more efficient particle packing. Empirical relations are proposed to predict postprimary consolidation shear modulus and postdensification cone penetration resistance. These relations may be used to extrapolate measurements taken immediately after ground modification. 911185 Variability in compaction control Noorany, I
J Geoteck Engug Die ASCE VII6, N7, July 1990, Pl1321136 Multiple runs of field density tests were made at three structural fills by nine engineering firms. Each site had been approved as having met 90% relative compaction. All tests were conducted at the same time and elevation and in close proximity to each other. Scatter in results as % of mean value was respectively 17, 15, and 26% for uniform silty sand, silty clay, and gravelly to cobbly fills. This is greater than the variability generally found for embankment dams. Need to improve standards of practice for structural fills and shortcomings of the test procedures are discussed. 911186 New oedometer with splitted ring for the measurement of lateral stress Senneset, K
Proc 12th International Conference on Soil Mechanics and Foundation Engineering, Rio de Jneiro, 13-18 August 1989 VI, P115-118. Publ Rotterdam: A A Balkema, 1989 An oedometer with a 3-section ring has been used to investigate the relation between horizontal and vertical stresses in soil samples under consolidation. The sections may be adjusted to clamp the soil at a set contact pressure, and controlled lateral deformation is permissable. Horizontal stresses are measured by LVDTs in the ring sections. Results are presented for a Glava clay from Norway. 911187 Pore pressure behaviour of soft clay Wei, R L; Sun, B; Wang, N X
Proc 12th International Conference on Soil Mechanics and Foundation Eugineeriug, Rio de Janeiro, 13-18 August 1989 VI, P139-142. Publ Rotterdam: A A Balkema. 1989 Undrained shear tests were carried out on remoulded soft clay under a variety of stress paths in triaxial, plane strain, and hollow cylinder apparatuses. Results show normally consolidated clay is contractive in these tests, which behaviour cannot be described in many soil models. A new constitutive model for clays is developed on the basis of the experimental data. Case histories of consolidation of foundations for a tank and a
sea wall are analysed using the proposed model and those of Duncan and Chang, and of Wei (1981). Results are compared and discussed. 911188 Interpretation of pre~arem~er test for settlement prediction (In French) Biarez. J; Cambou. B; Bozetto. P; Haghgou. M; Bouhanga. A; Garcia, L A
Proc 12tb International Conference on Soil Mechanics and Fomulation Engineering, Rio de Janeiro, 13-18 August 1989 VI, P185-186. Publ Rotterdam: A A Balkema. 1989 Results of measurements of displacements beneath a surcharge fill are used to test several methods of settlement prediction. A method is proposed for calculation of settlements on the basis of pressuremeter test results which uses the hyperbolic constitutive model of Duncan et al (1980) with some modification of parameters. 911189 Characteristics of expansive soil in Hefei, China Fan. J S; Yang. C B
Proc International Conference on Engineering Problems of Regiomd Soils, k i j u g , !1-15 August 1988 P572-575. Publ Beifing: International Academic Publishers, 1989 The geotechnical properties of expansive clays from the region between the Yangtze and Yellow rivers have been examined. Mineralogical and chemical composition, swelling and shrinkage, physical properties, stress strain behaviour and overconsolidation have been studied. The soils have low water content, high liquid limit, and dense textures, and high overconsolidation ratios. Net shaped fissures resulting from cyclic swelling-shrinkage are found in the field. Slope failures are common in cut slopes and hydraulicstructures. 911190 Three dimensional model for expansive soil on wetting-drying Li, X Y; Li, X W
Proc International Conference on Engineering Problems of Regional Soils, Bei~ug, 11-15 August 1988 P610-613. Publ Beifing: International Academic Publishers, 1989 A three-dimensional model for swelling-shrinkage of a linear elastic soil is presented. An isothermal model assuming basic independent variables strain tensor and water content is postulated. A non-isothermal model including temperature and temperature gradient as additional independent variables can be developed from this. An attempt is made to correlate parameters of the model with those used in current engineering practice. The model is applied to a soil layer subject to evapotranspiration and to the problem of earth pressure behind a retaining wall. 911191 Experimental research of expansive soils used for dam construction Liu, L D
Proc International Confereuce on Engineering Problems of Regional Soils, Beifi'q, 11-15 August 1988 P621-624. Publ Beijing: International Academic Publishers, 1989 The characteristics of expansive soils of the Sichuan region of China are described, including mineralogy, expansivity, plasticity and liquid limit. Softening on expansion and cracking on shrinkage must be taken into account when they are used in hydraulic structures. Several case studies of their use in cores of rock-earth fill dams are presented. They are mixed with non-expansive soils, and placed at optimum moisture content and compacted using heavy rollers to ensure high shear strength with low permeability, expansion and shrinkage.
© 1991 Pergamon Press pic. Reproduction not permitted