材料
Online ISSN : 1880-7488
Print ISSN : 0514-5163
ISSN-L : 0514-5163
44 巻 , 503 号
選択された号の論文の22件中1~22を表示しています
  • 楊 俊傑, 落合 英俊, 鈴木 敦巳, 北園 芳人, 林 重徳
    1995 年 44 巻 503 号 p. 990-993
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    The velocity field method was applied to stability analysis of the earth reinforcement. The effect of the reinforcing material in soils was considered by the internal dissipation energy in the velocity field method. The additional shear resistance of the reinforcing material mobilized at the slip surfaces was evaluated as a direct link between the reinforcement force and the increase of the confining pressure due to pull-outforce. The internal dissipation energy of the reinforcing material was considered using the direct reinforcement material force. The active earth pressure in wall-reinforced soil was calculated through use of the idea of this paper.
  • 大嶺 聖, 落合 英俊, 吉田 信夫
    1995 年 44 巻 503 号 p. 994-997
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    A method for evaluating the strength of the in-situ cement-treated soils is proposed based on the two-phase mixture model. The in-situ treated soil is regarded as a mixture which consists of the improved parts, so that the deformation modulus and the unconfined compressive strength are quantitatively estimated by taking account of the stress distribution and the stirring mix rate in the mixture. In order to confirm the validity of the propose method, the model tests and the in-situ tests were carried out. It may be concluded that the proposed method is capable of predicting the strength of the in-situ treated soils with a certain stirring mix rate by using those of the laboratory mixed soil and the in-situ original soil.
  • 光成 高志, 伊勢本 昇昭, 保井 美敏, 金子 治, 下田 正雄, 別所 三千夫
    1995 年 44 巻 503 号 p. 998-1002
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    This paper presents experimental results which verify the effectiveness of a liquefaction remediation measure using hard burned lime piles. Pile materials mixed with hard burned lime, blast furnance slag, artificial gypsum and sand are placed in predrilled holes lined with spiral casing. The water-absorption and expansion properties of the lime stabilize the soil. A lump of hard burned lime expands about four times after slake. The expansion rate of the pile, including that of the lime of 25%, corresponds to 0.4 under ordinary confining pressure. The compaction effect of hard burned lime piles is achieved by the compression of surrounding soil for both driving casing and expansion of the piles themselves.
  • 嘉門 雅史, 勝見 武, 太田 正彦
    1995 年 44 巻 503 号 p. 1003-1006
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    Evaluation of a dust prevention method for fluidized bed combustion coal fly ash and its applicability to geo-materials such as road construction or ground improvement are discussed. The coal fly ash generation as a by-product from fluidized bed combustion system is expected to increase significantly, because the use of this system has been spreading widely as independent means of electric power generation in some industries due to its technical merits. Though it has the advantage of containing lime and gypsum for hardening utilization, the coal ash is too dusty to utilize as geo-materials. In order to promote the utilization of the coal ash, “Non-Dusty Method” by using waste oil is proposed. The effect of the method on dust decrease was evaluated, and strength development and oil leachate characteristics, of both compacted coal ash and soft clay or waste sludge stabilized by the coal ash, were estimated experimentally. The results show that coal ash treated by the “Non-Dusty Method” can be effectively utilized as road materials or soil stabilizer without dust pollution during the execution. Therefore it can realize the treatment and potential utilization of not only the coal ash but also surplus soil and waste slurry or sludge generated from foundation works in large quantities.
  • 宋 永焜
    1995 年 44 巻 503 号 p. 1007-1010
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    It has been known qualitatively that allophane clay mineral influences the engineering properties of volcanic cohesive soil and lime is very effective for the soil stabilization. Therefore, the influence of allophane content on the lime stabilized soil was investigated by measuring the reactivity, lime adsorption, and pore size distribution. The main results obtained are summarized as follows:
    (1) Only hydrated halloysite is found in the soil containing allophane less than 50% and its reaction with lime produces hydrated gehlenite in 7 days of curing.
    (2) The optimum lime requirement increases with increasing allophane content.
    (3) The maximum amount of lime adsorption reaches at 14 days of curing, and it increases linearly with increasing allophane content.
    (4) In the soils containing less than 40% of allophane minerals, both the maximum amount of lime adsorption and the pore volume less than 0.1μm linearly increase with increasing unconfined compressive strength.
    (5) The pore volume within the pore diameter of 1-10μm increases linearly with increasing coefficient of permeability.
  • 西形 達明, 西田 一彦
    1995 年 44 巻 503 号 p. 1011-1014
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    The effect of the properties of geotextile on the separation function and the relationship between the reinforcement and separation function in road constructions were considered. The cyclic loads were applied on the surface of the pavement model in cylindrical mold. The tests consist of two type of series. In the first series, the effects of the properties of geotextiles on the quantity of the fine particles movement through the geotextiles are discussed. And the test rusults show that the unit weight of geotextile is applicable to estimate the separation function. In the second series, the interaction between the reinforcement and the separation function is considered. The reinforcement is a prime function when the ratio of the applied stress on the subgrade soil to the shear strength of the subgrade soil (σ/cu) is high. However, the separation can be an important function when the ratio is low.
  • 嘉門 雅史, 永井 秀忠, 和田 秀俊
    1995 年 44 巻 503 号 p. 1015-1018
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    Newly developed geotextile horizontal drains (abbreviated as GHDs) were introduced in reinforced soft clay embankments. GHDs consist of geosynthetic materials with reliably high transmissivity and core strength. The basic reinforcing characteristics of GHDs were investigated with a pull-out test and direct shear test. According to the test results, GHDs can be used for the reinforcement of soft clay embankments. A new design procedure was used for a calculation model including the GHDs, and the slope deformation and pore water pressure dessipation were estimated. The safety factors of the reinforced embankments using GHDs were esimated by steps of pore water pressure dissipation. The results clearly showed a good effect of the geotextile horizontal drains in the reinforcement of soft clay embankments.
  • 青木 一男, 福田 護
    1995 年 44 巻 503 号 p. 1019-1022
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    The main objective of this study is to clarify the relation between the consistency and the viscosity of soft clay. The soft clay can be considered as structual viscosity fluid. The consistency and viscosity were measured by using a variety of consistency tests and rehological tests. It was revealed that the relationship between FC value or Ff value and liquid limit was liniar. The yield value and the plastic viscosity were mesured by a rotational visco-meter. It was clealy seen that relationships between the yield value or the plastic viscosity and flowing time had a liniar correlation.
  • 友久 誠司, 澤 孝平, 内藤 永秀
    1995 年 44 巻 503 号 p. 1023-1026
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    The purpose of this study is to improve the trafficability or earthmoving property and strength of muddy soil which is high in water content and organic matter. In order to achieve this objective, the effect of additive mixtures such as concrete powder, paper sullage ash, coal fly ash and granular bentonite on the strength development was investigated.
    As a result, it became clear that with the addition of each of the used mixtures to the muddy soil, the strength of the soil was enhanced. In particular, the coal fly ash gave the largest hardening effect due to the production of ettringite. Consequently, if these mixtures are used, it is possible to decrease the quantity of hardening agent to be used and to reduce the curing period during which the strength reaches the expected level. When the strength is low, the unconfined compression test can not be performed, but it can be estimated by fall cone test. Therefore, it is possible to predict the long term strength and to utilize the results of this test for a quality control of the treated soil.
  • 防塵性について
    澤 孝平, 友久 誠司, 雀部 和男, 厚東 敦志, 鈴木 一幸
    1995 年 44 巻 503 号 p. 1027-1030
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    Most of the hardening materials used in the shallow soil improvement are powders. As they are spread on the ground and mixed with the soil, a lot of them are air/windborne and fly everywhere, which is called “dust” here. The dust has become a serious problem at sites near residential areas and for worker's health. The purpose of this study is the development of new “dustless hardening materials” containing a small amount of oil. They reduce the tendency of dust to become air/windborn, improve the working environment and keep the area in which they are used clean. The amount of dust produced from the new hardening materials is investigated by both laboratory work and field tests. As a result, it was found that by mixing a small amount of oil with the hardening materials, the amount of air/windborne dust produced decreased to an acceptable level, and provided for a productive working environment.
  • 藤平 雅巳, 小西 武, 清水 英治, 安田 進, 永瀬 英生
    1995 年 44 巻 503 号 p. 1031-1034
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    This paper indicates the possibility of prevention against liquefaction by mixing bentonite in sandy ground with the aid of electrohoresis. If this method is effective, it is useful to improve the subsoil condition of the existing structures by electrically transferring bentonite particles from the outside to the subsoil ground. Experiments were carried out in the laboratory to confirm the effect of soil improvement.
    The following results were obtained from the experiments.
    (1) Soil improvement using electrophoresis is effective in preventing sandy ground from being liquefied. (Fig. 3, 5, 6)
    (2) The effect of improvement increased more by using dispersant or flocculant. (Fig. 9)
  • 1995 年 44 巻 503 号 p. 1035-1040
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
  • 佐藤 嘉憲, 久保 光徳, 青木 弘行, 鈴木 邁, 吉田 旺弘
    1995 年 44 巻 503 号 p. 1041-1046
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    Recently, a contractile [PVA-PAA] gel that responds to electric potential was developed. For various applications of the [PVA-PAA] gel, it is important that the tensile properties and the structure of the gel are clarified. In this paper, the effect of PAA concentration was examined to obtain the relationship between the tensile property and the structure. [PVA-PAA] aqueous solutions were gelled by freezing-thawing cyclic processing (freezing: -60°C/5hr, thawing: +15°C/5hr, number of freezing-thawing cycles: 5 cycle).
    The results obtained are summarized as follows:
    (1) All of the initial Young's modulus, apparent Young's modulus and maximum stress decreased as the PAA concentration increased. These behaviors are attributable to not only the decrease of cross-linking density in PVA polymer chains by mixed PAA but also the hindering of orientation of PVA polymer chains by PAA under the deformed condition.
    (2) Both the strain energy and the maximum strain reached maximum at PAA concentration: 5wt%. This behavior is observed at the PAA/PVA molar ratio smaller than 0.3.
    (3) PAA contributes to the degeneration of tensile property at an infinitesimal deformation region and to the improvement of elongation of PVA polymer chain at a large deformation region. At the break point, the decrease of tensile property was due to the decrease of cross-linking density by PAA.
    (4) From the above results, it is suggested that [PVA-PAA] gels form phase-separated networks.
  • 佐藤 嘉憲, 久保 光徳, 青木 弘行, 鈴木 邁, 吉田 旺弘
    1995 年 44 巻 503 号 p. 1047-1052
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    In order to clarify the structure of [PVA-PAA] gels, the infrared spectra and differential scanning calorimetric data of the gels during the freezing-thawing cyclic process were obtained and the results of tensile properties and contractility by electric potential were discussed.
    The results obtained are summarized as follows:
    (1) During the freezing process, cross-linking occurred and the [PVA-PAA] aqueous solution was gelled. This is considered due to the increase of intermolecular hydrogen bonding in PVA.
    (2) During the freezing process, intermolecular hydrogen bonding between PVA and PAA seemed to increase in parallel with the number of freezing-thawing cycle.
    (3) The total exothermic enthalpy decreased during the freezing process for PVAs of DP 1700 and 3500, but increased for PVA of DP 2600. This behavior is attributable to the difference in PVA molecular weight.
    (4) The [PVA-PAA] gels form phase-separated networks that include PAA microdomains containing a large amount of water molecules.
    (5) The tensile properties and contractility by electric potential were improved with increasing freezing-thawing cycle. Those are due to the fact that [PVA-PAA] gel is phase-separated networks.
  • 木下 俊哉
    1995 年 44 巻 503 号 p. 1053-1059
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    A change in dominant toughening mechanism with microstructure in HP-Si3N4 ceramics has been investigated through the model calculation of toughening by crack deflection and through the atomic force microscope (AFM) observation of crack-tips. The microstructure of HP-Si3N4 was controlled by sintering temperature, ranging from 1773K to 2073K. The grain size was almost constant, 0.14-0.16μm, from 1773K to 1923K, and the aspect ratio increased from 1.6 at 1773K to 9.4 at 1923K. After the aspect ratio reached a maximum at 1923K, it decreased and the grain size increased. The aspect ratio was 5.6 and the grain size was 0.36μm at 2073K. The contributions of aspect ratio and grain size to toughening were separately evaluated using these specimens.
    Toughening by crack deflection was estimated by model calculation and by the crack shape in AFM image of crack-tips. Toughening by crack bridging was estimated by roughness at the upper and lower crack planes in the AFM images. When crack bridging contributed to toughening, stress was produced between the upper and lower crack planes, strain resulted from this stress and roughness resulted from this strain. When crack bridging didn't contribute to toughening, roughness wasn't observed. The model calculation and AFM results show that when the grain size was constant and the aspect ratio increased, the dominant toughening mechanism was crack deflection. When the grain size began to increase crack bridging came to contribute to toughening and the dominant toughening mechanism was the combination of crack deflection and crack bridging.
  • 内田 武, 楠本 韶
    1995 年 44 巻 503 号 p. 1060-1065
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    The effects of crystal orientation on fracture toughness and macrofractography of single-crystal ice specimens were examined by three-point bending test at -10°C. The loading rate KI was about 200kPa√m/s. Four types of single-crystal ice specimens, whose longitudinal directions were normal to the notch planes making respective angles of θ=0°, 45° (I), 45° (II) and 90° from the crystal orientation, were used. These specimens have a sharp edge notch made by pressing the edge of a razor blade on the bottom of the saw-cut slot. A macro replica was made on one side of the fracture surfaces using a dental impression material. The crystal orientation was measured using an etch-pitting method.
    The specimes of θ=0° and θ=90° exhibited similar fracture toughness values which offered a median value of Kc]50%=110.5kPa√m, and those of θ=45° (I) and θ=45° (II) also yielded similar values which gave Kc]50%=99.2kPa√m. The fracture toughness of columnar grained ice specimens estimated from that of single-crystal ice specimens was higher than the experimental values. Macro replicas clearly showed that the morphology of fracture surface was affected by those crystal orientations and it contained many traces of crack extension along the basal plane {0001} or the prismatic plane {1010}.
  • 合田 公一, 濱田 純一
    1995 年 44 巻 503 号 p. 1066-1073
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    The purpose of this study is to evaluate the statistical properties of creep-rupture lifetime in boron fibers by using a time-dependent Weibull distribution, from the viewpoint of materials reliability engineering. Axial creep-rupture tests on boron fibers were carried out under several constant loads and constant loading rates in air at 300°C, and the relevant Weibull parameters were estimated from the lifetime and strength data obtained in the above tests. The results showed that the estimated lifetime distribution curves were not in good agreement with the experimental data at other applied loads. The SEM observation for the fracture surfaces indicated that the kind of defect causing the long-term rupture was completely different from that of the short-term rupture. Therefore, a mixed time-dependent Weibull distribution based on a mixed distribution model was proposed for evaluating the scatter of the creep-rupture lifetime data. It was proved that, finally, the distribution proposed here was suitably applicable for predicting the creep-rupture lifetime distribution of boron fibers.
  • 小川 欽也, 倉石 晃, 西田 俊彦
    1995 年 44 巻 503 号 p. 1074-1079
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    The strength of continuous carbon fiber reinforced Si3N4 composite was investigated in a three-point bending test at low deflection velocity. On the load (P)-deflection (δ) curve inelastic behavior was observed together with AE (acoustic emission) events which may probably correspond to delamination at the interface of fiber and matrix, and/or cracking in matrix. The bending strength and the fracture morphology depend greatly on the H/L ratio where H is the height of specimen and L is the span, since the interlaminar shear strength of the material is unexpectedly lower than the tensile strength in the fiber direction. Consequently, the tensile strength can be adequately evaluated by reducing the specimen height to prevent shearing fracture. It is also found that the shear strength in the fiber direction is much lower on the perpendicular plane than on the parallel plane to the hot pressing. The fabrication process induced microcracking which degraded the elastic properties of the material. Significant load reduction and associated AE events were observed in the relaxation test and strong time-dependence of microcracking was revealed.
  • 山本 隆栄, 坂根 政男, 大南 正瑛, 山田 毅
    1995 年 44 巻 503 号 p. 1080-1085
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    This paper describes the tension-torsion low cycle fatigue (LCF) of 63Sn-37Pb solder tube specimens. Tension-torsion LCF tests were carried out at the strain rate of 0.5%/s, and suitability of strain and stress parameters for correlating multiaxial LCF lives was discussed. The Mises' strain, the maximum principal strain and the equivalent strain based on crack opening displacement are appropriate for the data correlation, but no stress parameter exists for correlating the multiaxial LCF within a factor of two scatter band. The Mises' stress gives a relatively small scatter of the data. In the tension tests, main cracks were propagated in the direction normal to the maximum principal strain, whereas they propagated in the principal shear direction in the torsion tests. The transition of crack propagation direction was found at the principal strain ratio of -0.54--0.64, where the principal strain ratio is defined as the ratio of the minimum principal strain to the maximum principal strain.
  • IWRC 6×Fi(29)の場合
    田中 正清, 鴻巣 真二
    1995 年 44 巻 503 号 p. 1086-1091
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    In order to clarify the property of internal damage of IWRC (independent wire rope core) wire ropes widely used for cranes, S-type bending fatigue tests were carried out on IWRC 6×Fi(29) wire ropes, under the condition of bending ratio (ratio of sheave diameter to rope diameter) D/d=16 and 12.8, and their wire breaking damages were quantitatively analyzed.
    It was shown that even under the condition of D/d=16 allowed for various cranes by the Crane Structural Standard, the internal wire breaks occur at the bottom and the nip portions of strands preferentially to the external wire breaks, that is, the visible ones. This preferentiality of internal wire-breaks was more distinct for the case of smaller D/d value of 12.8.
    Both the number of visible wire breaks and the total number of real wire breaks in strands can be approximated by power functions of the number of cycles N of reciprocally repeated S-bending. The number of internal wire breaks, therefore, can also be approximated by a simple function of N. These functional relations seem very useful for precise damage evaluation of this kind of wire ropes.
  • 宮崎 則幸, 船倉 成二, 宗像 健
    1995 年 44 巻 503 号 p. 1092-1096
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
    Experiments were carried out to study the effects of fiber volume contents, type of reinforcement fibers, and impact angle on the solid particle erosion behavior of fiber reinforced metals (FRMs). Three kinds of FRMs were used for the erosion experiments. They were the aluminum 6061 alloy reinforced by βSi3N4 whiskers, the aluminum 1070 alloy unidirectionally reinforced by Si-Ti-C-O fibers and the aluminum reinforced by SiC plain-woven cloths. The erodent particles used in the experiments were SiC abrasives with the diameters of 100μm to 150μm.
    The results obtained are summarized as follows:
    (1) In general, the erosion rate is larger in FRMs than in the corresponding matrix materials.
    (2) In the case where the size of reinforcement fibers is much smaller than that of the particles impacted, almost all the fibers removed from FRM are included in the matrix material removed by the impact of particles. In this case, the difference in erosion rate is small between FRM and the corresponding matrix material.
    (3) In the case where the reinforcement fibers exist in the form of unidirectionally long fibers or cloths, a lot of fibers are removed from the eroded surface of FRM. In this case, FRM has much larger erosion rate than the corresponding matrix material.
  • その2: 統一型構成式に基づく非弾性解析
    今谷 勝次
    1995 年 44 巻 503 号 p. 1097-1102
    発行日: 1995/08/15
    公開日: 2009/06/03
    ジャーナル フリー
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