Japanese Geotechnical Journal
Online ISSN : 1880-6341
ISSN-L : 1880-6341
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  • Toru INUI
    2020 Volume 15 Issue 3 Pages 419-420
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    The manuscript presents the history of JGS Symposium on Environmental Geotechnics, which was firstly launched on 1994, and the editorial policy of the special issue on environmental geotechnics, which consists of the technical papers selected from the Proceedings of 13th JGS Symposium on Environmental Geotechnics, as the foreword of this special issue.

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  • Yoshiaki KIKUCHI, Takayuki HIRAO, Makoto TAKEMOTO, Masatsugu KIKO, Rik ...
    2020 Volume 15 Issue 3 Pages 421-433
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    In order to use the premises of the offshore waste landfill site highly, it is necessary to construct piles into the bearing layer. In such a case, piles penetrate through base clay layer working as a barrier. At that time, the pile should drag the waste into the barrier ground. This study examined the dragging mechanism of the granular wastes during pile installation by small laboratory model experiments. In the research, waste dragging effects of shape of the pile toe, level of consolidation pressure to the clayey ground, particle size of granular wastes were discussed. As a conclusion, amount of dragged waste was reduced by the selection of the shape of pile toe. Wastes with larger particle than pile wall thickness would rotate during pile penetration if the particle was eccentrically driven by the pile, and it will be removed from the pile toe after some amount of pile penetration.

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  • Yuuki ITAYA, Kenji KUNINISHI
    2020 Volume 15 Issue 3 Pages 435-440
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    The purpose of this study was to develop insolubilized materials based on calcined dolomite, which has an insolubilizing effect regardless of the valence of selenium eluted from tunnel excavations. It was confirmed that selenium was eluted in the form of Se (IV) and (IV) from the tunnel excavation rock. In the calcined dolomite insolubilization, the selenium insolubilization performance was improved in proportion to the calcining degree of dolomite, and it had the insolubilization performance not only for Se (Ⅳ) but also for Se (Ⅵ). It is highly possible that the Se (Ⅵ) insolubilization performance is manifested by the reaction of the shear component and the insolubilizer component to form a hydrate, and the sorption or incorporation of Se (Ⅵ) in the hydrate.

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  • - leaching behavior of arsenite and arsenate acids -
    Hajime SUGITA, Terumi OGUMA, Ming ZHANG, Junko HARA, Yoshishige KAWABE
    2020 Volume 15 Issue 3 Pages 441-453
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    Adsorbents after being utilized in the purification of arsenic contaminated water can come into contact with solutions of various pH when discarded in the environment. The purpose of this study is to evaluate effects of solution pH on environmental stabilities of spent magnesium-based and calcium based adsorbents (MgO,Mg(OH)2,CaO and Ca(OH)2). The spent adsorbents adsorbed with arsenite or arsenate acid were prepared, they were placed in tubes with pH adjusted solution and then shaking tests (leaching tests) were performed. For any of the spent adsorbents, arsenite was easier to leachate than arsenate. The tests with solution pH of 3 to 11 showed that Mg-based adsorbents had higher environmental stabilities than Ca-based adsorbents, regardless of the valence of arsenic. In the tests with solution pH of 12 for arsenite, the spent Ca-based adsorbents were evaluated to have higher environmental stabilities than the spent Mg-based adsorbents.

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  • Daiki KAWAMURA, Hiroyuki ISHIMORI
    2020 Volume 15 Issue 3 Pages 455-463
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    In order to evaluate the performance of a bio-pile remediation system, the large-scale demonstration test was conducted. In this test, the oxygen concentration in the bio-pile gradually decreased with time, and the oxygen required for the degradation could not be supplied. The reason was considered that gas leakage occurred at the boundary between the gas extraction pipe and the soil embankment. This study aimed to clarify the effects of the gas leakage on the oxygen concentration in the soil using numerical simulation with an original boundary condition which can express them. As the results, it became clear that the decrease in the oxygen concentration observed in the demonstration test was significantly dependent on the gas leakage. When the gas leakage was prevented, the oxygen concentration in the soil embankment could be kept to a required level without large flow rate. The volume of the soil which can be remedied in the bio-pile system could be also increased to about three times as much as that under gas leakage.

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  • Sho OYAMA
    2020 Volume 15 Issue 3 Pages 465-470
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    This manuscript reports the results of laboratory tests that examined solidification/stabilization process of mercury-contaminated soil (artificially contaminated soil and actual contaminated soil) with magnesium oxide-based material (magnesia-based solidifying material) and blast furnace slag cement (type B), and reports the results of mercury leaching behavior of these insolubilized soil by long-term observation. It was confirmed that the magnesia-based solidifying material stably exhibited a high insolubilizing effect against mercury contamination for a long period of time, although the combination of auxiliary agent is necessary depending on the mercury concentration of the leachate. It was also shown that the insolubilization effect was exerted by the blast furnace slag cement (type B), that the insolubilization effect was increased by the progress of the age, and that the insolubilization effect was likely to be lowered by the neutralization (pH lowering).

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  • Satoshi SHINOHARA, Tatsushi KAWAI, Daisuke ISHIGAMI, Junichi KAWABATA, ...
    2020 Volume 15 Issue 3 Pages 471-478
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    In order to accumulate the data on the long-term leaching behavior of heavy metals, which is a problem when recycling waste, an exposure test was conducted for incineration ash granulated and solidified by portland blast-furnace slag cement. The exposure test carried out for 5 years showed that the concentration of hexavalent chromium, lead, arsenic, selenium, fluorine and boron that leached from granulated incineration ash were below Environmental Quality Standards for Groundwater Pollution in Japan. On the other hand, the concentration of leaching boron was found to increase in the long term due to the disappearance of cement hydrate in granulated incineration ash. In addition, to evaluate the leaching heavy metals caused by the long-term deterioration of the granulated incineration ash, an acceleration test and a particle size adjustment test were conducted. These tests showed that the leaching concentration of boron was increasing with carbonation, the leaching concentration of hexavalent chromium was increasing as the particle size decreases, and the leaching concentration of fluorine was less affected by carbonation and particle size.

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  • - Full scale demonstration test implying a small-scale magnetic separator and reactivating technique for iron powder -
    Yoh TAKAHATA, Madoka UMINO, Syunsuke KONDO, Masanori NEGISHI
    2020 Volume 15 Issue 3 Pages 479-486
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    A full-scale demonstration test was conducted to reduce arsenic concentration in surplus slurry generated by slurry shield construction process in mudstone layer, where iron powder having arsenic adsorption ability was mixed with the slurry and the iron powder was collected by a magnetic separator. As a result of intermittently treating about 1,200 m3 of arsenic contaminated slurry, almost full recovery of the iron powder flowed into the magnet separator was confirmed through the test period by using a magnet separator that can handle large volumes of slurry despite its small size. The arsenic concentration in the liquid phase decreased from 0.071 mg/L on average to 0.007 mg/L by adjusting the pH of arsenic contaminated slurry to 8.7 or less and treating in an iron powder mixing tank with a hydraulic residence time of 27 minutes. The iron powder was reactivated using a 1.0 M of ascorbic acid after 200 times of slurry treatment, and the arsenic adsorption rate was recovered to about three times. As a result, reactivating technique enables further repetitive use of iron powder as arsenic adsorbent.

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  • Mika ADACHI, Masahiko KATOH
    2020 Volume 15 Issue 3 Pages 487-496
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    A double column leaching test using excavated rock naturally contaminated by arsenic and non-contaminated soil with different sorption ability to understand the arsenic accumulation leached from the excavated rock into lower soil and its re-release by the alteration of chemical environment. A large part of arsenic (94%) leached from the excavated rock was accumulated as readily soluble, but water-insoluble phases into the lower soil immediately after arsenic leaching despite soil types. In addition, arsenic was not leached from the lower soil at the level exceeding the Japanese environmental standard for soil. Despite the soil types, the levels of arsenic re-release by the exposure of Na+ at the same concentration as sea water, weak acid to neutral pH, Ca alkaline, and the reduction condition were low and the arsenic concentrations in the plant was not enhanced. This study suggests that arsenic may be re-released by the extreme pH fluctuations after the re-use of excavated rock because the arsenic was accumulated as the readily soluble phases in the outflow side of lower soil, in particular lower Kd soil.

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  • Hiroyuki ISHIMORI, Jiajie TANG, Mikako NAKAGAWA, Hirofumi SAKANAKURA
    2020 Volume 15 Issue 3 Pages 497-508
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    In order to develop an environmental safety evaluation method for inorganic chemicals leaching from tsunami deposits, this study presents a simplified calculation method to solve advection-dispersion analysis with nonlinear adsorption/desorption model using a commercial spreadsheet software like Microsoft EXCEL. Adsorption/desorption parameters for Freundlich and Langmuir equations were determined by conducting the batch leaching tests having different liquid/solid ratio levels. Leaching concentration profiles in the column test were predicted according to the simplified calculation method. Comparing the predicted concentration profiles with the concentration profiles numerically simulated from FEM analysis, the accuracy of the simplified calculation method was less than 7.0% as relative error.

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  • Yuji SUGIMURA, Haruhiko SINOZAKI, Yuzoh AKASHI, Shodai UEMATSU, Satoru ...
    2020 Volume 15 Issue 3 Pages 509-517
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    In Japan, volcanic fine soil as well as highly organic soil are categorized as ‘problematic soil’. Since the engineering properties of these problematic soils greatly differ from those of textbook-type geomaterials, these soils are often improved in the engineering practice by mixing them with cement, for instance. It has been reported that some natural agents included in the problematic soils such as allophane and organic substance often impede cement solidification reaction. It has also been reported that the inhibition of the solidification reaction may be avoided by adding steelmaking slag comprising free lime. However, laboratory investigation into the effects of content of these agents on the cement solidification reaction is scarce. In this paper, the mechanical as well as chemical properties of various problematic soils are examined by using a single indicator, i.e., the content of alkali adsorption capacity. First, a fairly good relationship between the amount of allophane/organic substance and the alkali adsorption capacity was found for of several problematic soils tested. Second, it was manifested that the unconfined compression strength of cement/steel-slag mixed soil was much higher than that of comparative strength of cement mixed soil. The tendency was more pronounced as the alkali adsorption capacity increased.

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  • Shimon IDEGUCHI, Kiyoshi OMINE
    2020 Volume 15 Issue 3 Pages 519-527
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    Currently, various test methods for estimating in-situ strength have been developed. However, development of a test method for more easily estimating the strength of waste ground containing various materials and shapes is desired. In this study, we developed a new method combining cone penetration test and spiral pile pull-out test as a simple method to estimate in-situ strength. The results by laboratory tests were compared with the results of a conventional direct shear test for various geo-materials, and the proposed test was conducted at waste disposal sites containing plastics, and its applicability was confirmed. Although deposit waste site includes various types of materials, there is a correlation between the estimation of strength and the value measured by a conventional direct shear test. It is suggested that the proposed simple testing method is useful for obtaining an approximate value of in-situ strength on deposit waste materials.

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  • Shin SATO, Hirokazu Ohno, Kenji Tanai, Shuichi YAMAMOTO, Masaaki FUKAY ...
    2020 Volume 15 Issue 3 Pages 529-541
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    The coupled Thermo – Hydro – Mechanical behavior of a radioactive waste disposal facility during its re-saturation is affected by water vapor generated by the heating of pore water. In this study, a Thermo – Hydro – Mechanical coupled analysis of a confirmation test being conducted at the Horonobe Underground Research Center was performed, and how the increase in pore pressure caused by the generation of the water vapor affects the engineering barrier performance was discussed. As a result, by considering the water vapor in the analysis, the evaporation of the moisture content around the heater led to the increase in porosity by about 10% and the decrease in saturation by about 15% as the air pressure in the voids increased. Therefore, it was necessary to consider the effect of the water vapor generation due to the temperature rise near the heater in order to simulate re-saturation behavior in the long-term behavior evaluation of the buffer materials.

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  • - Ecofriendly Method for Seismic Reinforcement and Leakage Control of Embankment -
    Shinji FUKUSHIMA, Akira KITAJIMA, Shigeru TANI
    2020 Volume 15 Issue 3 Pages 543-549
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    The crushing and compacting embankment method is a dam embankment rehabilitation technique for fill type dam, and it is necessary to carry out large number of laboratory mixing tests from need to deal with two types of the cement-mixed soil, namely, the initial-stabilized soil and the crushed-and-compacted soil. Therefore, we proposed a simplified design method that can eliminate laboratory mixing tests as much as possible, in cases where they are applied to small-scale embankment repairing project that are difficult to perform cost-effectively as specified in the construction guideline for the rehabilitation technique. The simplified design method was established by the results of laboratory mixing test performed in embankment rehabilitation projects by the crushing and compacting embankment method. The proposed method is possible to reduce the number of tests conducted in laboratory mixing tests to about 20%, compared to the ordinary design method.

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  • Natsuki YAMAMOTO, Toshifumi MUKUNOKI, Erika SHIOTA, Takahiro SATO
    2020 Volume 15 Issue 3 Pages 551-561
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    2D Granulometric method analyzed pore structure of CT images in 2 dimensions obtained from X-ray CT scanner. Then, Lattice Boltzmann Method for two-phase flow using Shan and Chen model was applied to same images analyzed for in-situ simulation. Flow condition with a capillary number of 10-4 at inlet did not give enough pore pressure to seepage into pore size less than 9 voxels. Meanwhile, it was confirmed that the flow condition with a capillary number of 10-3 at inlet could give enough pore pressure which LNAPL could seep into the pore with less than 9 voxels. Hence, it was concluded that capillary number was important index to evaluate two-phase flow in porous media with various pore space.

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  • Ryota HINO, Toshihiko MIURA, Kenichi FUKUTAKE, Kenji NISHIDA, Tomotaka ...
    2020 Volume 15 Issue 3 Pages 563-571
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    This study evaluated the long-term stability soil contaminated with mercury and fluorine treated by in-situ insolubilization treatment. It is necessary to (1) quantitatively evaluate the elution suppression effect of the in-situ stabilization method and (2) understand the behavior of re-eluted contaminants. The former was evaluated by laboratory tests using insolubilized contaminated soil taken at an actual remediation project site. The latter was examined by numerical analysis simulating the behaviour of re-eluted contaminants. Based on the tests and analysis, it was expected that the elution from insolubilized mercury-contaminated soil would be sustained below environmental standard for 130 years and that from insolubilized fluorine-contaminated soil for more than 1,800 years. In the case of mercury, its dispersion would be limited less than 0.02m even after 100 years, due to insolubization which changed the chemical form of contaminants and decrease the water permeability of soil. It was concluded that it is possible to quantitatively evaluate the long-term elution suppression effect of in-situ insolubilization treatment.

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  • Hiroshi KUBOTA, Koga SHIGEIZUMI, Yosuke NAGAYAMA, Takuro FUJIKAWA, Chi ...
    2020 Volume 15 Issue 3 Pages 573-580
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    In order to reduce the amount of waste to be disposed of in landfill, the recycling of municipal solid waste (MSW) incineration bottom ash is of urgent need in Japan. This study aims to recycle MSW bottom ash as civil engineering materials. MSW bottom ash from 6 locations nationwide was used to investigate the effect on the elution characteristics by sprinkling water and conducting carbonation via the column test, as well as the impact on the mechanical characteristics using bottom ash from one of the locations. While Pb was confirmed to be immobilized due to carbonation, the tendency for the elution of Cr(VI) was shown to have increased. It was also suggested from decrease in the modified CBR value that carbonation affects the mechanical properties of bottom ash. Additionally, the effects of mixing iron materials and auxiliary materials with MSW bottom ash to immobilize heavy metals as well as to improve mechanical properties.

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  • Hirokazu KISHI, Kaoru KOBAYASHI, Yasuo YANAKA
    2020 Volume 15 Issue 3 Pages 581-598
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    Curtain-grouting is necessary to improve hydraulic and dynamic properties for dam foundation stability. Adequate evaluation of grouting improvement is extremely important for its rational execution. Such evaluation is conducted in accordance with the non-exceedance probability for a target Lugeon value. Ordinarily, for the grouting area, the probability is calculated from Lugeon values of regular pattern holes and supplementary ones individually. The probability for regular pattern holes conducted equally in the area represents the overall grouting effectiveness. However, although the probability for the supplementary holes does not represent the effectiveness, it has been regarded in many cases as the criterion of effectiveness. A new rational process of evaluating the probability is provided herein: it synthesizes both holes. Additionally, a rational process is provided for the reduction of supplementary holes. These processes were demonstrated as useful for curtain-grouting quality management at a domestic dam construction site.

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  • Hiroshi HIRABAYASHI, Takayuki KAWAGUCHI, Shunzo KAWAJIRI, Satoshi YAMA ...
    2020 Volume 15 Issue 3 Pages 599-608
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    In this study, based on results of field vane shear test conducted on 21 domestic and 9 overseas clay soils and laboratory tests using collected undisturbed samples at each location, correlations between field vane shear strength and undrained shear strength obtained from constant volume direct box shear test and unconfined compression test were examined. As a result, it was clarified that the field vane shear strength measured at a clay soil with a high permeability, a large coefficient of consolidation and a possibility of a large organic content becomes relatively large. Accordingly, the correlation equation for obtaining undrained shear strength from the field vane shear test equivalent of the one from the laboratory tests was derived based on the data except in above mentioned ground conditions.

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  • Takashi AKIYAMA
    2020 Volume 15 Issue 3 Pages 609-622
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    The design of civil engineering structures should consider the socio-environmental harmony with their surroundings. On the other hand, for important facilities or buildings with super long-term maintenance functions, it is desirable to plan these facilities at a geographically-stable location, considering the uncertainties of natural hazards occurring in the future. There exists a requirement to establish an evaluation method/criteria, to ascertain the long-term probability of occurrence and level of influence of various natural phenomena i.e. active fault movement, land upheaval, volcanic activity, heat effect, etc.
    In order to avoid the risk of improper site selection that raises social concerns about natural disaster, after detailed site investigation has been performed, it is important to judge the super long-term or probabilistic site hazard in advance. The current study proposes the usage of an evaluation tool named, “Super long-term natural hazard prediction method”, for the selection of a suitable site for facility establishment, especially focusing the possibility of active fault movement and land upheaval.

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  • Hayato HAMAGUCHI, Wuwei MAO, Junichi KOSEKI
    2020 Volume 15 Issue 3 Pages 623-634
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    Model tests were conducted to clarify whether AE tomography could be applied to observe the microscopic phenomena during pile penetration in sand. Firstly, the accuracy of AE tomography was verified. Then, the behavior of AE source location during closed-end pile penetration and open-end pile penetration in sand was tested. The results showed that the accuracy of AE tomography was high in the center of sensor allocations; the patterns of AE source distribution during closed-end pile penetration could be categorized into “shrinkage with fixed center position”, “overall movement while keeping the same shape”, and “overall movement with elongation into the direction of pile penetration”, where most of the measured signals had frequency components of 100 kHz or below; and the shape of AE source distribution became different when the pile that exhibits different supporting mechanism was used.

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  • Akira FUKAI, Akihiko OSHIMA, Kengo YASUDA, Yuji MATSUTANI
    2020 Volume 15 Issue 3 Pages 635-642
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    There are JIS specifications and ISO specifications (Weight sounding) in the Swedish weight sounding (SWS) test. Currently, JIS revision work of SWS test is being carried out, and a consistency with ISO specifications which was enacted in 2017 is required to correspond to internationalization. There are significant differences in shape of screw point (SP) and rod diameter in the two specifications, and it is considered that they may affect the test results. Therefore, we carried out comparative tests at five sites under different terrain and ground conditions. In addition to these conditions, the effects of abrasion were also examined using damaged SP. In this sounding test, we adopt an automatic testing machine that can automatically control during self-sinking and maintain a constant rotation speed. Test results of JIS and ISO almost agreed. In the case of cohesive soil, the variation in results was particularly small.

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  • Hirokazu ITO, Makoto ISHIMARU, Kentaro NAKAI, Toshihiro NODA
    2020 Volume 15 Issue 3 Pages 643-652
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    In the 2011 Earthquake off the Pacific coast of Tohoku, extensive liquefaction occurred in the Kanto region. This resulted in the settlement and inclination of thousands of utility poles. In urban areas, utility poles are often installed in narrow easements with limited clearance. Therefore, a simple and inexpensive countermeasure is desired. In this study, we attempted to reduce the settlement and inclination of utility poles in the liquefied ground by providing drain holes in the utility pole. In the centrifugal model tests conducted using pole models with drain holes at the bottom and sides, settlement and inclination decreased in relation to the amount of drainage. Therefore, it was determined that the drainage method has a definite effect on the reduction of both settlement and inclination of utility poles in the liquefied ground.

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  • Shinya INAZUMI, Kazuhiko KOJIMA, Hiroyuki HASHIDA, Takahiro KATO
    2020 Volume 15 Issue 3 Pages 653-663
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    From a geotechnical point of view, soil is uncertain and heterogeneous. Therefore, for example, if an attempt is made to determine the soil classification without a precise test, certain experiences may be required, and individual differences may appear in the determination. Against the background of inheriting these knowledges and being susceptible to experience, this study aims to accumulate and pass on the knowledge of engineers and to provide certain indices for on-site judgments where individual differences are likely to occur. The purpose of this paper is to show the possibility of image recognition by artificial intelligence using machine learning for the purpose of expanding the use cases of artificial intelligence (AI) in Japan. In this study, the authors conducted a simple deep learning using a model using a neural network and showed that the deep learning AI can be applied to soil classification.

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  • Toshihiro KAWANAMI, Kengo SAIJYOU, Masaru TAKEMOTO, Yukio NAKATA
    2020 Volume 15 Issue 3 Pages 665-674
    Published: September 30, 2020
    Released: September 30, 2020
    JOURNALS FREE ACCESS

    Soil nailing method, which has been widely used on cut slopes, is being adopted to the embankment slopes as a preventive maintenance measure against earthquakes, and to ensure the safety during the restoration of collapse due to heavy rain. However, there are no guidelines for applying the method on the embankment reinforcement, and only a limited number of reports on the design and applied cases. This paper is on the case where the soil nailing method was applied to the embankment slope as an emergency restoration method of the collapse due to torrential rainfall. The reinforced slope did not show any failure during the “In July 2018 torrential downpour” in July 2018, even though the directly neighboring embankment slope failed. The length of the nailing rod was calculated using the assessed value of the ultimate shaft friction in the Cut Slope Reinforcement Earthwork Guideline, in order to reinforce the shortage of the deterrence necessary to stabilize the failed slope. As a result, the reinforcing effect on the embankment slope, and the applicability of the guideline for the cut slope was confirmed. In addition, the points of attention on the construction when applying the method to the embankment, and the importance of using the drainage method in conjunction were also recognized.

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