Articles

  1. Evaluation on the Results of Multistage Shear Test Download Article

    Hormdee D., Kaikeerati N., and Angsuwotai P.
    • Article Type: Research Article
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    • Pages (140-143)
    • No of Download = 2589

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    Shear strength is a very important soil property to determine the stability of foundations, retaining walls, slopes and embankments. To solve those problems in geotechnical engineering, shear strengths are usually determined from laboratory tests performed on specimens prepared by compaction in the laboratory or undisturbed samples obtained from exploratory soil borings. In order to determine the shear strength parameters, the soil specimens are required at least 3 identical samples. To eliminate the effects of soil variability on the result, multistage testing is used to maximize the amount of shear strength information that can be obtained from only one specimen by using several confining pressures. Test results demonstrate that is possible and convenient to perform multistage shear test on compacted soil to measure shear strength. The direct shear tests were carried out using the multistage technique and the results are quite well comparable to those of traditional shear tests.

  2. BioClean and Liquid Biofertilizers a New Way to the Green Area Download Article

    Sittisak Uparivong
    • Article Type: Research Article
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    • Pages (144-147 )
    • No of Download = 542

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    The one selection to solve the problems of severely damaged by the tragic earthquake and tsunami is presenting a new way to green area planet. The aim is to be creating a pilot project to support green area for environmental places living. BioClean and liquid biofertilizer projects are attempting to be a new way for the natural balance of combined green area. This generation of bioclean had produced by the donation of various flowers during the graduated ceremony of khon kaen university since 2010, and adding the 18 zymogenic synthetic microorganisms (18 ZSMs) with molasses as substrate. Furthermore, the liquid biofertilizers had produced as similar processes as bioclean excepting differential raw materials by using the previous research product of liquid biofertilizers, which were produced by using vegetables, fruits, herbal crops, etc. Results of microorganism population of bioclean and liquid biofertilizer products were 1.0 x 108 to 8.0 x 1012 cfu/ml, which mainly serviced for environmental and agricultural sections, respectively. Including, the both products were presented focus on supporting to the green area for living places and related to climate change. The service result of project products was activated on the event of “Temples Big Cleaning Day 2011” by servicing for cleaning and the green area at the two temples near khon kaen university, which satisfactory result obtained 4.26 average score value or 85.3%, evaluated by the expert board of ten committees’s considerations.

  3. Load Settlement Relationships of Circular Footings Considering Dilatancy Characteristics of Sand Download Article

    Yusuke Tomita, Tatsuaki Nishigata, Takeshi Masui and Shintaro Yao
    • Article Type: Research Article
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    • Pages (148-153 )
    • No of Download = 924

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    In order to elucidate the mechanical properties of load-settlement relationships of spread foundations on sand ground, experimental and analytical study on strain hardening and dilatancy of sand is needed. Here we present the theoretical properties which were derived from circular footing model experiment and computer simulation. The model experiment was carried out through vertical loading on circular footing, and used relative density and tank dimensions as parameters. The quantitative relationship between load and settlement was analyzed through FEM simulation with SMP-Cam-Clay model, which is capable of estimating the dilatancy of sand. The results are summarized as follows; In both cases of dense and loose sand models, before reaching the ultimate load, the load-settlement relationship obtained from FEM simulation corresponded with that of obtained from the experiment. After reaching the ultimate load, “Terzaghi’s bearing capacity line” corresponded with the load-settlement relationship obtained from the experiment. In the case of medium-dense sand models, some binding effect of a soil tank rectangle was recognized. The effect was considered to be exerted by the positive dilatancy of the sand, which occurred steadily with the settlement progresses.

  4. GIS-Based Soil Liquefaction Hazard Zonation due to Earthquake Using Geotechnical Data Download Article

    Md. Habibullah, Rama Mohan Pokhrel, Jiro Kuwano and Shinya Tachibana
    • Article Type: Research Article
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    • Pages (154-160 )
    • No of Download = 714

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    Liquefaction is an earthquake ground failure mechanism that occurs in loose, saturated granular sediments and has caused extensive damage to the ground. Liquefaction potential zoning is the process of estimating the response of soil layers under earthquake excitations. Ground conditions play important roles in the prediction of hazards caused by earthquake. Thus to evaluate seismic hazards for a wide area, ground formation history along with soil properties must be known. This paper describes the ground conditions and behavior of Satte city as a result of Earthquake. In this paper, Geographical Information System (GIS) is used to obtain soil liquefaction hazard map. Spatial variations of soil properties are estimated from the available borehole locations where SPT –N values, water table depth and grain size distribution are known. These maps can be useful for assessing the approximate areas affected by hazards and for disaster prevention planning.

  5. Development of Functional Carbon Nanotubes -Asphalt Composites Download Article

    Tatsuo Shirakawa, Akio Tada and Noriyasu Okazaki
    • Article Type: Research Article
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    • Pages (161-165)
    • No of Download = 464

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    The purpose of this study is to prepare asphalt composites containing CNTs and to elucidate the characteristic properties of CNTs-dispersed asphalt composites.  In the present study, such composites were prepared using several types of asphalt emulsions as a binder.  As a result, both nonionic and anionic emulsions kept dispersed state, when combined with as-prepared CNTs.  However, cationic emulsions failed to keep dispersed state.  After several additional systematic experiments, it was found that cationic emulsion successfully retained an adequate dispersion state, when as-prepared CNTs were treated with acid solution and the following incremental addition of the pretreated CNTs.  The three types of CNTs-asphalt composites demonstrated higher performances in both penetration and microwave-absorption tests than asphalt composites including carbon black powder instead of CNTs, when the mass percentage of all carbon materials was the same.

  6. The Relationship between Soil Suction and the Maximum Unsaturated Undrained Shear Strengths of Compacted Khon Kaen Soil Download Article

    R. Nuntasarn and Veerawat Wannakul
    • Article Type: Research Article
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    • Pages (166-170 )
    • No of Download = 959

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    The objective of this study was to evaluate the maximum unsaturated undrianed shear strengths of compacted Khon Kaen soil, which were determined from UU triaxial tests. The samples were compacted at 85% of maximum dry density by standard method. The samples were not measured soil suction during the test, but rather estimated soil suction from the soil water characteristic curve (SWCC) based on the volumetric water content of the sample during the test. The drying SWCC for the compacted Khon Kaen loess was determined from three methods, which were a hanging column method, a pressure plate method and an isopiestic humidity method. The maximum unsaturated undrained shear strength of compacted Khon Kaen loess was investigated in the Transition Zone. The relationship between soil suction and the unsaturated undrained shear strength of compacted Khon Kaen soil was a good related in the form of exponent of the value of R2 = 0.98.

  7. Ultimate Strength and Fatigue Life of Concrete Elements Reinforced with Carbon Fiber Sheet Based on Continuum Damage Mechanics Download Article

    Hidenori Tanaka and Yutaka Toi
    • Article Type: Research Article
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    • Pages (171-178 )
    • No of Download = 574

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    Continuum Damage Mechanics (C.D.M) was applied to evaluate the mechanical behavior of concrete structural elements reinforced with carbon fiber sheet (CF-sheet) under quasi-static and cyclic loading. A constitutive equation for elasto-plastic damageable solids is formulated by using Drucker-Prager’s equivalent stress and identified by the uniaxial compressive and tensile experimental results for concrete, tensile results for CF-sheet. And then finite element analyses are carried out  for  real-scale cantilever reinforced concrete slabs and concrete blocks with CF-sheet. Finally It was concluded that the application of C.D.M for concrete structural ultimate strength and fatigue durability comparing the experimental data and the calculation by 2-dimensional finite element method  (F.E.M) was very useful.

  8. Post-Earthquake Rapid Inspection Planning for Bridges in Western Kentucky Download Article

    Norimitsu Koike and Issam E. Harik
    • Article Type: Research Article
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    • Pages (179-184 )
    • No of Download = 721

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    This paper presents a methodology for the rapid assessment of bridge’s safety and functionality following a major seismic event in rural areas. The proposed model considers a combination of the bridge ranking prior to the seismic event and a computer assist program to identify the “efficient completion time” strategy for the post-earthquake bridge inspection team to inspect the critical bridge’s components damage level. Application of the proposed methodology is conducted on the Purchase Parkway in Western Kentucky. By setting the required inspection time to 40 minutes per bridge, it is estimated herein that a non-trained inspection team and without computer assist would conduct the inspection for all 61 bridges in a period exceeding 40 hours. On the other hand, by setting the time to 20 minutes for a well-trained team with computer assist, it will need 22 hours to inspect all 61 bridges, and 5 hours to inspect provisionally the 9 high risk bridges.

  9. An Aquatic Environment Assessment Model for the Comprehensive Assessment of Environmental Measures in Metropolitan Areas Download Article

    Tetsuo Morita, Tsuyoshi Baba, Hiroshi Sugita, Kazuhiro Nomura, Shinya Tsukada and Takashi Hashimoto
    • Article Type: Research Article
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    • Pages (185-190 )
    • No of Download = 468

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    We have developed simulation models that describe the effects that urban environmental measures have on urban activities such as transportation and land use, and evaluate them from the perspective of the environment, quality of life, and the economy. This paper presents an aquatic environment assessment model that may be added to the above-mentioned simulation models, and presents the results of a case-study of the Sendai metropolitan area. The results confirmed that the aquatic environment assessment model is reproducible, with sufficient accuracy in assessing the aquatic environment. The case-study assessed the impact that land use measures, sewer planning, and water quality planning had on the environment, and made clear their effect on watershed retention capacity and the water quality improvement index.

  10. Changes and Issues in Green Space Planning in the Tokyo Metropolitan Area: Focusing on the "Capital Region Plan" Download Article

    Tetsuo Morita, Yoshihide Nakagawa, Akinori Morimoto, Masateru Maruyama and Yoshimi Hosokawa
    • Article Type: Research Article
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    • Pages (191-196 )
    • No of Download = 1344

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    Large-scale green space planning in the Tokyo Metropolitan Area was formulated in 1939 with the "Tokyo Green Space Plan," and a greenbelt was proposed, however the plan was cancelled due to the end of the war.  In 1958 the "First Capital Region Plan" was formulated, and a greenbelt was again proposed, however the second and later plans became plans that approved of urbanization. This paper focuses on the Capital Region Plan, and aims to (1) organize changes in green space planning in the Tokyo Metropolitan Area, (2) analyze the circumstances of urbanization of the area designated a greenbelt in the First Capital Region Plan, and (3) extract issues regarding green space planning in the Tokyo Metropolitan Area.

  11. Design of Single Pile Foundations Using the Mechanics of Unsaturated Download Article

    Vanapalli S. and Taylan Z.N.
    • Article Type: Research Article
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    • Pages (197-204 )
    • No of Download = 1167

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    The load carrying capacity of single piles are commonly estimated using the well known a[1], b [2-3] and l [4] methods. These methods are also used in engineering practice for unsaturated soils even though the a, b and l  methods are based on conventional saturated soil mechanics. In this study, a series of single model pile tests were conducted in a laboratory environment to study the influence of matric suction on the pile shaft capacity in a statically compacted fine-grained soil. The results of the study show that the shaft capacity of single piles is significantly influenced by the contribution of matric suction. Based on the experimental results, the conventional a, b and l methods were modified to estimate the total shaft resistance of piles in unsaturated soils by including the influence of matric suction. The modified methods can also be used for estimating the variation of shaft capacity of single piles with respect to matric suction using the Soil-Water Characteristic Curve (SWCC) and the saturated soil shear strength parameters. The modified a, b and l methods are promising for use in engineering practice to estimate the ultimate shaft bearing capacity of single piles placed in unsaturated soils.