SOILS AND FOUNDATIONS
Print ISSN : 0385-1621
Volume 24, Issue 1
Displaying 1-15 of 15 articles from this issue
  • KUNIAKI SATO, KUNIO WATANABE, NOBUYOSHI KOTAJIMA
    1984 Volume 24 Issue 1 Pages 1-8
    Published: March 15, 1984
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    With respect to hydraulic analysis of the groundwater movement in fractured rocks, the determination of permeability and the establishment of resistance law is one of the most important tasks. In particular, it is needed to clarify the flow characters of an elementary fissure in a number of interconnected fractures on the basis of dynamic analysis of viscous fluid. This paper presents the flow analysis and resistance law for the elementary fissure having irregular and rough wall in the interstitial channel. Typical flows of viscous fluid through single fissure models were analyzed by the finite difference method of Navier-Stokes and vorticity equations. In addition, an experimental spectrum analysis of fracture samples obtained from granite rocks was carried out in the laboratory. Then, a permeability formula was proposed for the single fracture.
    Download PDF (805K)
  • MASARU HOSHIYA, J.N. MANDAL
    1984 Volume 24 Issue 1 Pages 9-16
    Published: March 15, 1984
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    A number of laboratory tests on pullout resistances of square and rectangular model anchors made of aluminium plates in loose sand have been taken up for this investigation. The main purpose of this paper is to present some recent model test results for square and rectangular plates in sand at constant compactive effort and outlines the pullout resistance of anchor plates with a vertical axis of different sizes and a load displacement relationship of the model tests. Moreover, the ultimate anchor resistance has been expressed in terms of nondimensional force coefficient and breakout factor. For rectangular and square anchors, the breakout factor increases with relative depth of embedment ratio to a certain extent and then tends to approximately constant at greater depths. The critical embedment ratio for rectangular anchors is about five while there is no meaningful results in case of square anchors. An attempt has also been focussed to understand the basic behavior of embedded anchors. The depth of embedment, size of anchors and the relative density of the sand are also important factors in this investigation.
    Download PDF (752K)
  • FRANS MOLENKAMP
    1984 Volume 24 Issue 1 Pages 17-33
    Published: March 15, 1984
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    Some of the best existing constitutive models for granular materials are based on the microkinematic assumption that the velocity gradient is a direct result of interparticle slip. For instance in the stress-dilatancy theory (Rowe, 1962, 1971) and in the double sliding, free rotating model (de Josselin de Jong, 1971, 1976, 1977 a, b) the mechanism of interparticle slip plays a central role. Oda, Konishi and Nemat-Nasser (1982) have concluded from biaxial compression tests that also interparticle rolling appears to be a major microscopic deformation mechanism. This conclusion was based on the observed relative displacements of the interparticle contact points.In this paper a method for the determination of the relative importance of the interparticle mechanisms of slip and rolling is applied in which the measured macroscopic velocity gradient is decomposed into 2 components, namely a component due to interparticle slip and a component due to interparticle rolling and combined rotation of the rigid particles in contact. From one of the aforesaid biaxial compression tests it is found that in the post-peak interval the contribution to the velocity gradient by the mechanism of interparticle slip is still larger than the contribution by interparticle rolling but the latter is significant too.
    Download PDF (1625K)
  • TAKESHI TAMURA, SHOICHI KOBAYASHI, TETSUYA SUMI
    1984 Volume 24 Issue 1 Pages 34-42
    Published: March 15, 1984
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    We investigate a numerical approach to analyze the limit state of soil structures, assuming that the mechanical property of the soil is rigid plastic. It is well known that the collapse analysis of frame structures can be formulated as the linear programming problem through the upper bound theorem of plasticity. Recently this method was extended to continuum. Since the nonlinear programming problem must be treated in this case, no well-established technique is found out in the literature. There also is a little theoretical confusion concerning the constraint conditions and the indeterminate pressure (total mean stress).In this paper, we firstly formulate the problem by using the upper bound theorem and secondly show that the minimization of the upper bound is equivalent to finding out the equilibrium state with the indeterminate pressure. The present numerical procedure is illustrated by typical problems, i. e., bearing capacity of shallow foundation and slope stability. Good agreement between the present results and well-known solutions confirms that our approach can be used as a general method for the limit analysis of soil structures.
    Download PDF (903K)
  • H.B. POOROOSHASB, S. PIETRUSZCZAK
    1984 Volume 24 Issue 1 Pages 43-48
    Published: March 15, 1984
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    The form of constitutive equations for soils that use multi yield loci are stated. The stability of the material is examined in the light of Drucker's criterion which postulates that a material is stable if in an incremental loading process the increment of incremental plastic work is positive semidefinite. It is shown that while if a single family of yield surfaces is used then the so-called normality condition (the coincidence of the plastic potential surface and the yield surface) must hold. On the other hand the normality condition is not necessarily satisfied, even if Drucker's criterion is, if a multitude of families of yield loci are employed. As an example it is shown that the model proposed by Poorooshasb and Yong (1982) to describe clay deformation does satisfy the stability condition, nevertheless one family of the yield loci and the corresponding plastic potential surfaces are not coinciding.
    Download PDF (580K)
  • AKIRA ASAOKA, MINORU MATSUO
    1984 Volume 24 Issue 1 Pages 49-62
    Published: March 15, 1984
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    This study intends to give theoretical bases for the observational procedure of predicting multi-dimensional consolidation behavior, in which the observations of deformations and/or excess pore water pressures raised in the early stages of consolidation are utlized for the prediction of those behavior in the successive future stage.The developed procedure is based on the Biot's linear elastic consolidation theory and is applicable to inhomogeneous soil mass with anisotropic soil properties concerning both elasticity and permeability. For the purpose of practical use the procedure is introduced in two ways, one is under constant load condition and the other, under gradual load application. Furthermore, taking field engineering practice into consideration, the method is presented for two cases, one is the case when excess pore water pressure behavior can be observed and the other, not observed.The numerical simulations using finite element analyses and some actual field observations show the high applicability of the proposed procedure.
    Download PDF (1261K)
  • TATSURO MURO
    1984 Volume 24 Issue 1 Pages 63-76
    Published: March 15, 1984
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    Compression and shear deformation properties of dry fresh snow and dry age-hardened snow were investigated in a cold room. And those properties of fresh wet snow were tested in-situ using a portable loading plate, and vane or ring shear test apparatus. Then, a shallow snow performance of tracked vehicle was analysed by means of energy equilibrium equation.The experimantal and analytical results obtained here are as follows : (1) Modulus of elasticity and coefficient of propagation of brittle compression of dry fresh snow is an exponential function of initial density.(2) For dry snow, the maximum draw-bar-pull (D.B.P.) of tracked vehicle running on shallow snow terrain is obtained at zero slip ratio, and it increases linearly with average contact pressure. And the influence of snow compaction on its D.B.P. is comparatively small.(3) For wet shallow snow deposit, the maximum D.B.P. is obtained at a few percentage of slip ratio. Both energy losses of compressive deformation and slippage are small. And, there is an optimum average contact pressure in the range of 27.4 to 42.1 kPa, to get a maximum D.B.P..
    Download PDF (1573K)
  • NORIHIKO MIURA, HIDEKAZU MURATA, NORIYUKI YASUFUKU
    1984 Volume 24 Issue 1 Pages 77-89
    Published: March 15, 1984
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    Yield curves of sand in a particle-crushing ragion were determined by a multi-step stress path method under triaxial compression and extension stresses. The yield curves were found to have the characteristic dq/dp=G(η), irrespective of the stress path, where q is the deviator stress, p, the effective mean principal stress and η, the stress ratio. Using the relationship between dq/dp and η, families of yield curves were depicted in both compression and extension stress regions. Based on a new expression for energy dissipation per unit volume, a yield curve equation was derived and this equation was proved to be well comparable with the experimental curve. An equation for predicting the stress-strain relation was also presented. This stress-strain equation was shown to be very conformable with the experimen talstress-strain curves in conditions of constant σr and constant p in both triaxial compression and extension stress regions.
    Download PDF (1069K)
  • KENJI ISHIHARA, VLAD PERLEA
    1984 Volume 24 Issue 1 Pages 90-112
    Published: March 15, 1984
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    During the Vrancea earthquake of March 4, 1977, severe damage was incurred to the ground in the old riverbed deposit of the Dimbovitza river in the city area of Bucharest, Romania, due to the development of liquefaction. Following the earthquake extensive in-situ investigations were carried out to clarify subsurface soil conditions by means of the Dutch cone penetration test and the Swedish automatic ram sounding test. On the basis of the results of these tests, analyses were made for the liquefaction at two sites in this area ;one site where apparent signs of liquefaction were observed and the other site where no such sign was visible on the ground surface following the earthquake. The result ot the analyses indicated that liquefaction could occur in the sand deposit underlying the surface layer composed of clayey silt. However, because the surface crust was not thick enough at one site, it was broken up and the liquefied sand migrated through the fissures upwards on the ground surface. In contrast to this, the surface layer at the other site was sufficiently thick to prevent such breach and consequent sand ejection from occurring during the earthquake.One of the most alarming aspects of the collapse in the ground was several huge sinkholes which developed in the flood plain area of the Danube river near the town of Giurgiu in Romania. As a result of boring investigation, cavernous limestone formation was found to exist at a depth of about 20 m below a thick sand deposit of alluvial origin. It is then speculated that the cave-in must have taken place as a result of ravelling failure in the weathered upper portion of the limestone formation. In order to provide some quantitative interpretation to the mechanism of the sinkhole development, an instability analysis was made with respect to the seepage conditions in the weathered limestone layer which might have been altered due to the increase in pore water pressure in the upperlying alluvial sand deposit during the earthquake. The result of the analysis indicated that the seepage-associated instability caused by the increase in pore water pressure in the sand deposit is most likely to be an immediate cause of the catastrophic sinkhole development in the ground during the Vrancea earthquake.
    Download PDF (2670K)
  • FUMIO TATSUOKA, FRANS MOLENKAMP, TSUYOSHI TORII, TSUTOMU HINO
    1984 Volume 24 Issue 1 Pages 113-128
    Published: March 15, 1984
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    The results of a series of direct shear tests on lubrication layers and other related tests performed to get a better insight into the methods of lubrication between the sand samples and the platens are described. The lubrication layers used consist of grease and latex disc. To get a good quality of lubrication, it is first needed that the grease has an enough resistance against squeezing out when compressed. The inclusion of fine solid fillers in the grease increases this resistance, while as a result lubrication when not squeezed out becomes less effective with the increase in the amount of fillers as well. The quality of lubrication depends on the following factors at least; (1) the quality of grease (the viscosity of the base silicone oil and the amount of fine solid fillers included in the grease), (2) the normal stress, (3) the composition concerning latex disc and silicone grease. For the lubrication at low normal stresses, the following composition may be recommended; (1) the grease should be composed of low viscosity silicone oil and an appropriate amount of fillers, and (2) a smooth surface should be facing the grease layer. For the lubrication at high normal stresses the following composition may be recommended; (1) the grease should be composed of high viscosity silicone oil and an appropriate amount of fine fillers, and (2) a composition with which stress concentrations in the grease layer are reduced. By using an appropriate method of lubrication the apparent angle of friction for a lubrication layer placed between a fine angular sand mass and a steel platen can be much smaller than 1 degree for normal stresses of 150∼670 kN/m2 at least.
    Download PDF (1627K)
  • HIDEO SEKIGUCHI
    1984 Volume 24 Issue 1 Pages 129-147
    Published: March 15, 1984
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    A theory of undrained creep rupture of normally consolidated clay is developed within the framework of an elasto-viscoplastic constitutive model. Particular emphasis is placed on giving the analytical expressions whereby all important aspects of undrained creep rupture are clearly explained. The principal expressions derived are as follows : the time-independent failure condition in terms of effective stress; the equation governing the migration of effective stress state during undrained creep; the relationship between rupture life and creep stress; the equation governing the effective stress state at the minimum creep rate; and the deviatoric creep equations governing the time-dependent variations of deviatoric strain and of deviatoric strain rate in the whole process of creep rupture. The validity of the creep rupture theory is successfully verified based on the results of undrained triaxial creep tests on isotropically, normally consolidated samples of a natural clay.Furthermore, the possible influence of anisotropic consolidation history on the subsequent, undrained creep rupture behavior is concisely indicated.
    Download PDF (1561K)
  • MASATOSHI SAWAGUCHI
    1984 Volume 24 Issue 1 Pages 148-150
    Published: March 15, 1984
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    Several kinds of instruments are available, for measuring the deformation of soils. Some of these instruments are used for observation of slope sliding or of the lateral flow of subsoils. The gauges reported on herein are newly developed for measuring shear strain in soils electrically. This report describes the results of sliding tests performed on sand in a small test box, measuring shear strain with the use of the gauges.
    Download PDF (475K)
  • HAKUJU YAMAGUCHI
    1984 Volume 24 Issue 1 Pages 151-156
    Published: March 15, 1984
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    It is pointed out firstly that Fox's method of computing the settlement of an embedded foundation is unsuitable because the solution given by Fox based on the superposition of Mindlin's first solution does by no means conform to the stress state which can be visualized within the soil mass around a foundation. It can be concluded accordingly that the settlement thus computed is in general greater than the observed settlement, and especially when the depth of a foundation is large the degree of error will be excessive.Secondly, a new settlement formula is proposed by considering such factors as the net foundation pressure, the modulus of deformation and the bearing capacity below the foundation level which produce an essential effect on the settlement behavior of an embedded foundation.
    Download PDF (667K)
  • Hiroshi Oikawa, Masaki Tsushima
    1984 Volume 24 Issue 1 Pages 173-182
    Published: March 15, 1984
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    Download PDF (1223K)
  • Yoou Yamada
    1984 Volume 24 Issue 1 Pages 183-191
    Published: March 15, 1984
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    Download PDF (1167K)
feedback
Top