Articles

  1. Updating Predictive Models for Vertical Swell Percentage of Expansive Clays Download Article

    Moshe Livneh
    • Article Type: Research Article
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    • Pages (205-212)
    • No of Download = 413

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    Since the publication of the Israeli swelling model in 2011, new swelling test results have become available (all together on 897 undisturbed clay specimens), enabling an updating of the existing swelling model. Thus, it is logical to update this existing model to obtain a more accurate prediction of vertical swelling under a given vertical pressure exerted on the clay under consideration. This paper concentrates on the required updating, together with (a) a search for modified independent variables for the model equations and (b) a division of the 897 undisturbed specimens into two separate groups, one for the A-4 and A-6 material and the second for the A-7-5 and A-7-6 material, in order to enhance the accuracy of vertical swelling prediction. The final recommendation is to use two swelling models (the general one for the A-7-5 and A-7-6 material and the specific one for the A-4 and A-6 material), based on modified independent variables listed in the paper.

  2. Experimental Development of New Type Reinforced Soil Wall Download Article

    Hara T., Tsuji S., Yoshida M., Ito S. and Sawada K.
    • Article Type: Research Article
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    • Pages (213-218 )
    • No of Download = 860

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    Our aim in this study is to develop a new type of reinforced soil walls as substitute for concrete ones. The structure that piles are inserted into reinforced soil wall body has been studied as the new type structure. In this development, a static-loading test, a dynamic centrifuge model test and an impact-loading test were carried out in order to confirm the practicability of the structure to actual diverse sites. In this paper, the details of the static and impact loading tests are introduced and the practicability of the structure is discussed.

  3. Experiments and Numerical Modeling of a Rockfall Protective Wire Rope Fence Download Article

    Phuc Tran Van and Koji Maegawa
    • Article Type: Research Article
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    • Pages (219-226 )
    • No of Download = 1070

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    To protect existing structures in mountainous areas against rockfall, various protection methods have been developed. A new type of rockfall protection fence is constructed of posts, wire ropes, and wire netting. To verify the performance of this rock fence, both experiments and numerical analysis based on finite element code were conducted. Collision tests were performed, in which areinforced-concrete block rolled down a natural slope and struck the rock fence at the end of the slope.The performance of energy absorbers, which are effective in preventing wire ropes from breaking, was investigated. To measure the acceleration of a reinforced-concrete block rolling down a steep slope, a new system of measuring instruments was developed.

  4. Removal of Copper from Water by Adsorption onto Banana Peel as Bioadsorbent Download Article

    M. A. Hossain, H. Hao Ngo, W. S. Guo and T. V. Nguyen
    • Article Type: Research Article
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    • Pages (227-234)
    • No of Download = 402

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    Banana peel, a fruit waste were used to produce bioadsorbent through environment friendly process. It were cut, washed, dried, grounded into powder and used for copper removal. Copper adsorption onto banana peel was depended upon the controlling parameters such as particle size, doses, pH, contact time, agitation speed and temperature. Slightly acidic water (pH = 6) was found to be suitable for copper removal. Equilibrium data were well fitted (R2 = 0.998) with the Langmuir and Freundlich isotherms. The monolayer adsorption capacity was 27.78 mg/g. The calculated RL and ‘n’ values has proved the favorability of copper adsorption onto banana peel. Copper adsorption was followed the second order kinetic properly rather than other models. The equilibrium adsorption capacity was 1.439, 8.849, 18.182, 31.250 and 71.429 mg/g when initial copper concentrations were 10, 50, 100, 200, and 400 mg/l respectively. Solvent 0.1N Sulphuric acid showed higher desorption of copper (94%) and adsorption-desorption process can be continued till seven cycles efficiently.

  5. Changes in the Residents’ Consciousness due to Environmental Improvements After Consolidation of Municipalities Download Article

    Takashi Hashimoto, Akira Yuzawa, Tetsuo Morita and Shinya Tsukada
    • Article Type: Research Article
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    • Pages (235 240 )
    • No of Download = 344

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    The purpose of this paper is to clarify the changes in the consciousness of residents due to environmental improvements after consolidation of municipalities. The focus of this research is to quantify both “increases in residents’ satisfaction” and the “increased sense of unity in residents’ consciousness” due to environmental improvements during the four years after consolidation. The city analyzed is Isesaki City, Gunma Prefecture, Japan, which has already carried out consolidation. In analyzing residents’ consciousness, we performed factor analysis and covariance structural analysis using the results of surveys of residents’ consciousness. The results of the analysis showed that (1) residents’ satisfaction has increased, but (2) the sense of unity in residents’ consciousness has not increased. This paper is intended to suggest that (1) residents’ satisfaction can be increased by improving the environment for four years after consolidation, and (2) increasing the sense of unity in residents’ consciousness by improving the environment for four years after consolidation is extremely difficult.

  6. A Study on Evaluation of Quality of Life in Consideration of Water/Green Environment Download Article

    Tetsuo Morita, Yoshihito Kogure, Hiroshi Sugita, Tsuyoshi Baba, Shin-ya Tsukada, and Naoki Miyazato
    • Article Type: Research Article
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    • Pages (241-246 )
    • No of Download = 429

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    Recently, the interest about water/green environment rises. But, it does not become clear enough, that water/green environment influences Quality of Life. The purpose of this study is the analyzing Quality of Life quantitatively with the data of the questionnaire survey, from the viewpoint of water/green environment. The subject area was Maebashi City, Gunma Prefecture. We used “factor analysis” and “covariance structure analysis”. Result of factor analysis we obtain five factor of the Quality of Life: Safety, Convenience, Environment, Housing conditions, Comfort. In addition we clarify evaluation structure of Quality of Life in consideration of water/green environment such as the river or the park by using covariance structure analysis. As the result, we made clear that Quality of Life is different depending on individual attribute and district characteristic, and that water/green environment affected Quality of Life. And we show measure effects.

  7. Study on Evaluating Rock Block Stability by Using A Remotely Positioned Laser Doppler Vibrometer Download Article

    Guichen Ma, Kazuhide Sawada, Hideki Saito, Fumiaki Uehan and Atsushi Yashima
    • Article Type: Research Article
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    • Pages (247-252 )
    • No of Download = 602

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    This paper examines a new method of evaluating the stability of a rock slope using a remotely positioned laser Doppler vibrometer (LDV). An experiment program was conducted by using physical models and a numerical analysis was performed to evaluate the new method. The LDV measurements agreed with conventional seismometer measurements. The dominant frequency of the blocks varied with the stability, and dominant frequency and the amplitude varied with the block size. The numerical model was used to examine a concrete block adhered to a concrete base with different contact areas. The dominant frequency of the blocks determined using the numerical model agreed with those obtained from the physical experiments. These results demonstrated the effectiveness of LDV for evaluating the stability of rock slopes.

  8. Buckling Behavior of Composite Triangular Plates Download Article

    T. Farsadi, E. Heydarnia and P. Amani
    • Article Type: Research Article
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    • Pages (253-260 )
    • No of Download = 1119

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    This paper is to do a brief research on the buckling behavior of composite triangular plates with various edge boundary conditions and in-plane loads. It may be regarded as a right and simple numerical method for the analysis of composite triangular thin plate using the natural Area coordinates. Previous studies on the solution of triangular plates with different boundary conditions were mostly based on the Rayleigh-Ritz principle which is performed in the Cartesian coordinate. In this method, the energy functional of a general triangular plate is derived and the Rayleigh-Ritz method is utilized to derive the governing eigenvalue equation for the buckling problem. The geometry is presented in a natural way by mapping a parent triangle and the integrals are evaluated analytically. The polynomial terms in the Area coordinates are employed to interpolate plate deflection. In this approach, the convergence is always assured due to the completeness of interpolating polynomials. Extensive buckling factors are presented for several selected right-angled and isosceles triangular plates of various edge support conditions and subjected to composite thin plates under various in-planes compressive loads and the results are validated to the other results.

  9. Response of Tapered Piles under Lateral Harmonic Vibrations Download Article

    Ahmad Dehghanpoor and Mahmoud Ghazavi
    • Article Type: Research Article
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    • Pages (261-265 )
    • No of Download = 358

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    This paper presents a new method for analysis tapered piles under lateral harmonic vibration. The behavior of tapered piles is assumed to be as elastic and linear. The soil consists of some elastic horizontal layers that they are homogeneous, isotropic, and linearly visco–elastic. The pile is divided to some segments and the differential equation for a given desirable segment is obtained and solved. Then the dynamic complex stiffness parameters are derived for the pile head. Parametric studies have been performed to investigate the influence of pile geometry, soil properties, and loading details on pile-soil system amplitudes. It has been found that under lateral harmonic vibrations, with increasing the pile taper angle, the resonant amplitude decreases. In addition, it has been concluded that under lateral harmonic vibrations, a tapered pile experiences lower amplitude than a cylindrical pile of the same length and material volume.

  10. A Review of Electrokinetic Treatment Technique for Improving the Engineering Characteristics of Low Permeable Problematic Soils Download Article

    Nasim Mosavat, Erwin Oh and Gary Chai
    • Article Type: Research Article
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    • Pages (266-272 )
    • No of Download = 612

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    The use of electrokinetic (EK) treatment which is a comparatively new methodology is being investigated in some parts of the world as a viable in situ soil remediation and treatment method. The principles of EK treatment method involve applying a low direct current or a low potential gradient to electrodes inserted in the low permeable soils that cannot readily drained. The transportation of charged species across the soil involves several complex mechanisms such as electrolysis, electro-osmosis, electro-migration and electrophoresis. This technique can also be applied/enhanced by introducing desirable non-toxic chemical compounds such as lime or cement solutions to the soil by introducing them at the appropriate electrode. The combined effect of these processes together with various geochemical reactions alters the chemical composition of the soil porous medium and thereby alters the physicochemical properties of the soil. Although the technology has been approved to be practical in many laboratory bench scale experiments and small-scale pilot field tests, complicated features such as many electrochemical reactions and soil contaminant interactions are still not fully understood, therefore there is a need for further research to be conducted for a better understanding of physicochemical changes in problematic soils and efficiency of this newly developed technology.