Articles

  1. Spatial Interpolation of consolidation properties of Holocene clays at Kobe Airport using an artificial neural network Download Article

    Kazuhiro Oda, Minsun Lee and Shotaro Kitamura
    • Article Type: Research Article
    • View Abstract
    • Pages (423-428 )
    • No of Download = 2596

    Abstract

    close

    The spatial distribution of the consolidation properties for a seabed must be appropriately estimated to accurately predict the consolidation settlement due to large-scale reclamation. The soil properties must be estimated at arbitrary positions in the ground from data collected during soil investigation. In this study, an artificial neural network was applied to spatially interpolate consolidation properties such as the natural water content, void ratio, plastic index, compression index, and pre-consolidation pressure. The estimation accuracy of consolidation properties was judged based on four indexes: R2, G, MARE, and SR. The artificial neural network estimated the appropriate consolidation properties with high accuracy; this confirmed the availability of spatial interpolation of consolidation properties by using an artificial neural network.

  2. Unique Grout Material Composed of Calcium Phosphate Compounds Download Article

    Satoru Kawasaki and Masaru Akiyama
    • Article Type: Research Article
    • View Abstract
    • Pages (429-435 )
    • No of Download = 770

    Abstract

    close

    To employ calcium phosphate compounds (CPCs) in ground improvement measures such as the reinforcement of soil and rock, we examined suitable conditions for CPC precipitation and performed unconfined compressive strength (UCS) tests of sand test pieces cemented by CPC. Two types of phosphate stock solution and two types of calcium stock solution were used to prepare the reaction mixtures and CPC precipitation was confirmed in all reaction mixtures. The volume of CPC precipitation in the mixture increased as the pH rose from strongly acidic to around neutral. The UCS of sand test pieces cemented by 1.5 M diammonium phosphate and 0.75 M calcium acetate tended to increase with time, reaching a maximum of 87.6 kPa. The results indicate the practical feasibility of using unique and new CPC grouts as chemical grouts because of their self-setting property and as biogrouts because of the pH dependence of precipitation.

  3. Response of Piered Retaining Walls to Lateral Soil Movement Based on Numerical Modeling Download Article

    Siamak Pahlevanzadeh
    • Article Type: Research Article
    • View Abstract
    • Pages (436-441 )
    • No of Download = 1507

    Abstract

    close

    The response of individual retaining walls employed as a preferred slope stabilization technique, to lateral loading has been widely explored in the literature. The present study focuses on the response of piered retaining walls, i.e. retaining walls supported by a pile foundation system, to lateral soil movement. Numerical analysis results by MATLAB have revealed wall-soil-pile interaction mechanism with different effective height of wall, spacing, diameter and number of piles, using different soil properties, which quantifies the behavior of piered retaining walls owing to lateral soil movement. Based on a numerical configuration sensitivity study, the relationship between lateral loading and pile/wall deflection, shear and bending moment under different influencing parameters has been established. Optimum effective parameters are accordingly defined and relevant guidance on choosing appropriate piling configuration is provided, which can be of practical use in engineering design.

  4. Centrifuge Model Tests and Finite Element Analyses on Seismic Behavior of Quay Walls Backfilled with Cement-Treated Granular Soils Download Article

    Hayano, K., Morikawa, Y., Fukawa, H., Takehana, K.4 and Tanaka, S.
    • Article Type: Research Article
    • View Abstract
    • Pages (442-449 )
    • No of Download = 1008

    Abstract

    close

    Dynamic centrifuge model tests and finite element analyses (FEA) were conducted to investigate the seismic behavior of quay walls backfilled with cement-treated granular soils (CTGS). In particular, the effects of the CTGS fill depth and fill range on seismic behavior were investigated. The centrifuge model tests showed that no liquefaction was generated in the CTGS backfills. The quay wall’s horizontal displacement induced by the seismic loading decreased with increases in the CTGS fill depth because the earth pressure acting on the quay wall was reduced. In addition, a wedge-shaped CTGS fill was found to be effective at reducing the horizontal displacement of the quay wall. However, the results of the dynamic FEA indicate that the wedge angle of the CTGS fill should be carefully designed.

  5. Group Effects of Piles Due to Lateral Soil Movement Download Article

    Hongyu Qin
    • Article Type: Research Article
    • View Abstract
    • Pages (450-455 )
    • No of Download = 1137

    Abstract

    close

    Laboratory model tests have been conducted to investigate the responses of piles subjected to lateral soil movement. The results of a single pile test and four tests on two piles arranged in a row perpendicular to the direction of soil movement are presented. The development of maximum bending moment, maximum shear force, and pile deflection with soil movement and the largest pile response profiles for the single pile and pile groups are compared. Group effect was evaluated using group factor which is defined in terms of the measured maximum bending moment. The major findings are (1) the pile head conditions (free or capped) are insignificant on piles subjected to lateral soil movement when arranged in a row, (2) the group factor decreases as the pile spacing reduces, (3) a linear relationship exists between the maximum bending moment and maximum shear force for both the pile groups and single pile.

  6. Estimation Method of Amount of Tsunami Disaster Wastes during the 2011 off the Pacific Coast of Tohoku Earthquake Download Article

    Minoru Yamanaka, Naoya Toyota, Shuichi Hasegawa and Atsuko Nonomura
    • Article Type: Research Article
    • View Abstract
    • Pages (456-461)
    • No of Download = 611

    Abstract

    close

    A huge amount of disaster wastes was accumulated along coastline areas of the Tohoku region by tsunami during the 2011 off the Pacific coast of Tohoku Earthquake. It is very important to estimate amount of tsunami disaster wastes as for quick recover and revival of damaged areas. This paper describes a method of wastes amount estimation based on the officially published data analyzed in GIS platform. As a result of this study, it was found that there is a well relationship between the amount of disaster wastes and submerged area, population, tsunami height and so on, and that the number of damaged buildings within the submerged area using GIS software (Arc Map) has high accuracy in comparison with the published data.

  7. Evaluation of Pile Lateral Capacity in Clay Applying Evolutionary Approach Download Article

    Alkroosh I. and Nikraz H.
    • Article Type: Research Article
    • View Abstract
    • Pages (462-465)
    • No of Download = 401

    Abstract

    close

    This paper presents the development of a new model to predict the lateral capacity of piles inserted into clayey soils and subjected to lateral loads. Gene Expression Programming (GEP) has been utilized for this purpose. The data used for development of the GEP model is collected from the literature and comprise 38 data points. The data are divided into two subsets: Training set for model calibration and independent validation set for model verification. Predictions from the GEP model are compared with the results of experimental data. The model has achieved a coefficient of correlation, r, of 0.95 for training and validation sets and average prediction ratio (APR) of 0.97 and 1.04 for training and validation sets respectively. The results indicate that the GEP model performs very well and able to predict the pile lateral capacity accurately.

  8. Suction Controlled Triaxial Apparatus for Saturated-Unsaturated Soil Test Download Article

    Luky Handoko, Noriyuki Yasufuku, Kiyoshi Oomine and Hemanta Hazarika
    • Article Type: Research Article
    • View Abstract
    • Pages (466-470)
    • No of Download = 970

    Abstract

    close

    A suction controlled triaxial apparatus has been developed in Geotechnical Engineering Laboratory of Kyushu University. The apparatus has been designed to obtain mechanical properties of unsaturated soil such as shear strength and stiffness, as well as hydraulic properties of unsaturated soil, i.e. soil water retention curve by measuring change of drained water volume during applied matric suction. Not only for unsaturated condition, this apparatus can be also used to conduct conventional test on saturated soil. This paper focuses on the performance of the apparatus, by performing a series of multistage test on unsaturated soil under drying and wetting path. The hydraulics and mechanical properties of unsaturated soil are presented and discussed.

  9. Experimental Study Concerning Impact Characteristics by Collision of Weight on Sand Cushion over Steel Beam Download Article

    Tam Sy Ho, Hiroshi Masuya and Naoto Takashita
    • Article Type: Research Article
    • View Abstract
    • Pages (471-476)
    • No of Download = 1103

    Abstract

    close

    Sand cushion is often utilized in rockfall protection structures as a shock absorber. Impact by rockfall is considered one of the most important variable loads for protection structures. To clarify the evaluation method and the buffering effects of impact force, the series of weight impact experiment were conducted. A simple supported double steel beam was used to reproduce the behavior of structure. Experiments were carried out by the free fall of the weight to the sand tank installed at the center of simply supported double steel H beams. The impact force of the weight and transmitted force under the sand tank as well as displacements of beam and strains of the beam were measured. Dynamic characteristics of impact force, transmitted force to the steel beam and behavior of the beam were investigated. Dynamic interaction between sand and beam, shock absorbing effect of sand and also the transfer ratio of kinetic energy of rockfall to the structure were shown.

  10. Lateral stress induced due root-water-uptake in unsaturated soils Download Article

    Mu’azu Mohammed Abdullahi and Nazri Bin Ali
    • Article Type: Research Article
    • View Abstract
    • Pages (477-481)
    • No of Download = 422

    Abstract

    close

     

    A two-dimensional (2-D) lateral stress was modeled as a result of matric suction change caused by vegetative induced moisture transfer. The negative pore-water pressures are estimated through governing partial differential equations for unsaturated soils. The results of the of simulated root water uptake are used as an input for the prediction of 2-D lateral stress in a stress-deformation analysis in an uncoupled manner. The soil is allow to expand and contract free laterally, as the as water is being abstracted from the soil. A mature Lime tree located on a Boulder clay sub-soil for period covering a full spring/summer drying period was used as a case study. The result shows interdependence of lateral and vertical stress generated resulting from root water-uptake.

  11. Macro viscous regime of natural dense granular mixtures Download Article

    Anna Maria Pellegrino and Leonardo Schippa
    • Article Type: Research Article
    • View Abstract
    • Pages (482-489)
    • No of Download = 424

    Abstract

    close

    An experimental study was carried out on several dense-granular mixtures (debris flow mixtures and natural sand mixtures) using several rheometrical tools in order to investigate the rheological behaviour of the “fluid-like” material mixture. The results obtained on debris flow-water mixtures suggest that, in the fluid-like regime, the typical rheological behaviour is that of yield stress fluids and the rheology is strongly dependent on the grain concentration. The velocity profile obtained on natural sand-Newtonian fluid mixtures identify the shearing zone and explain the dependence of the flow characteristics (i.e., transition from quasi-static regime to liquid regime) on viscosity and shear rate. The results suggest that, in that field, the interstitial fluid viscosity influence the sharing material layer and that no flow is possible for solid fraction higher than a maximum value.

  12. Strength and Aging of Cement Treated Low Plastic Soils Download Article

    Fabien Szymkiewicz, Antoine Guimond-Barrett, Alain Le Kouby, Philippe Reiffsteck and Sonia Fanelli
    • Article Type: Research Article
    • View Abstract
    • Pages (490-494)
    • No of Download = 472

    Abstract

    close

    Deep mixing is a method frequently used for various applications ranging from ground improvement and confinement to foundations. With the increase of the use of deep mixing for foundations, it is imperative to better define the mechanical behaviour and ageing of the material, which depends on the cement content and grain size distribution. This study aims to quantify the impact of these parameters as well as the percentage of fines on the mechanical behaviour of the mixed material. A number of unconfined compression tests were carried out. The results showed that it was possible to predict the strength of the mixed material after seven and 28 days of curing, based on the cement content and the percentage of fines.

  13. Landslides in Tea Plantation Fields in Shizuoka, Japan Download Article

    Jun Sugawara
    • Article Type: Research Article
    • View Abstract
    • Pages (495-500)
    • No of Download = 822

    Abstract

    close

    Shizuoka Prefecture in Japan is famous for the production of quality Japanese green tea. Approximately 45% of Japan’s tea is produced in Shizuoka. In this region, tea plants are often grown in hilly terrain. Therefore, due to this topographic setting, as well as other natural characteristics including geotechnical and geological conditions, tea plantation fields are occasionally subject to landslides. This paper investigates the relationship between the tea plantation fields and landslide prone areas in Shizuoka Prefecture. In this study, tea plantation fields are described from the engineering standpoint. Typical mechanisms of landslides that have occurred in the tea plantation fields are also studied. A series of investigations reveal that there are many common points between the tea plantation fields and the landslide prone areas in this region.

  14. Rock slope stability problems in Gold Coast area, Australia Download Article

    Shokouhi Ali, Gratchev Ivan and D.H. Kim
    • Article Type: Research Article
    • View Abstract
    • Pages (501-504)
    • No of Download = 727

    Abstract

    close

    The Tamborine Mountain area of the Gold Coast, Australia often faces rock slope failures during rainy seasons. To have a better understanding of the factors that may affect the slope stability, several rock slope sites examined in detail to assess the effect of discontinuities formed in the rock masses, and degree of weathering of the rocks on the overall stability of slopes. Different methods of slope stability analysis such as kinematic approach and slope mass rating, were applied to investigate the potential failure mode and predict the behavior of rock slopes in the future. This paper will present results of this work and make comparisons between different methods of rock slope stability analysis.