International Journal of the JCRM
Online ISSN : 2186-4225
ISSN-L : 2186-4225
3 巻, 1 号
選択された号の論文の5件中1~5を表示しています
2007.01.01-2007.12.31
  • Hiroo KUMASAKA
    2007 年 3 巻 1 号 p. 1-6
    発行日: 2007/03/01
    公開日: 2014/01/11
    ジャーナル フリー
    In this note, support characteristic curves were derived through numerical analysis and plotted by the characteristic curve method, and the applicability of support characteristic curves was considered. As a result, it was shown that for elastic ground, a state of equilibrium can be obtained at the point of intersection of the ground characteristic curve and the support property curve as in the characteristic curve method, and that the influence of support stiffness on the stress release ratio can be taken into account. For elastoplastic ground, however, a state of equilibrium did not occur at the point of intersection. It was also shown that one reason for this is that the influence of the passage of the tunnel face and the influence of the excavation method are not reflected in the ground characteristic curve in the characteristic curve method.
  • Su Su kyi, Tu D. NGUYEN, Kenji AOKI, Yoshitada MITO, Kabul Basah SUR ...
    2007 年 3 巻 1 号 p. 7-15
    発行日: 2007/09/01
    公開日: 2014/01/11
    ジャーナル フリー
    This paper describes the influence of landslides parameters as weighted scores that are applied in the risk assessment. The mechanism of landslide in tropical area is studied in the catchment area along Kalibawang channel of the west of Kulon Progo region, Yogyakarta, Indonesia. The dominant factors of landslides are studied rigorously by field working and identified the input parameters for multivariate statistical analysis by using quantification theory type II. The parameters in this analysis are simplified for the purpose of basis application in similar landslide prone area of tropical region. The weighted score resulted from this analysis is used to evaluate the possibility of landslides. These scores are input to GIS to construct the landslides hazard map and assess the risk in area based on risk value and level of potential of dangerous. The critical rainfall is identified based on historical rainfall with landslides for hazard warning criteria.
  • Kimihiro HASHIBA, Seisuke OKUBO, Katsunori FUKUI
    2007 年 3 巻 1 号 p. 17-20
    発行日: 2007/12/01
    公開日: 2014/01/11
    ジャーナル フリー
    One of the important methods for investigating time-dependency is to measure the loading-rate dependency of peak strength, however, no experimental method has been established for accurately measuring it from a small number of samples. In this study we propose such a method. A single sample is loaded at alternating strain rates to obtain stress-strain curves for both strain rates.The loading-rate dependency of peak strength obtained via this method was nearly identical to previous results obtained using conventional methods, including results obtained under confining pressure. We also investigated the loading-rate dependency of the stress-strain curve for the post-failure region for which few results have been published. Under confining pressure, the corrected stress-strain curve, obtained by multiplying the stress of the complete stress-strain curve obtained at the fast strain rate by a constant determined by the ratio between the fast strain rate and slow strain rate, is nearly coincident with the stress-strain curve for the slow strain rate. This is an interesting result and represents new knowledge that may help elucidate failure mechanisms in the post-failure region.
  • Yujing JIANG, Yuji YAMASHITA, Yoshitake ETOU, Bo LI
    2007 年 3 巻 1 号 p. 21-29
    発行日: 2007/12/01
    公開日: 2014/01/11
    ジャーナル フリー
    The stability and support effects of large-scale underground openings located in the jointed rock masses are principally ruled by the mechanical behavior of discontinuities. The major deformations of the host rock masses containing underground openings originate from the normal and shear movements along the walls of discontinuities. A number of experimental and numerical investigations have demonstrated the significant influences of discontinuities on the mechanical, thermal and hydraulic behaviors of discontinuous rock masses, indicating that the deformational mechanism and stability of underground facilities in the discontinuous rock masses depend not only on the existing discontinuities but also the new cracks, which are generated and thereafter keep propagation due mainly to the stress relaxation induced by excavation. In this study, a two dimensional distinct element method was used to analyze the behavior of underground cavern based on in-situ geological data and experimental feature of rock joints. The properties of rock joints used in the analyses were obtained by using the newly developed high-performance direct shear test apparatus. Some local deformational behaviors of deep underground cavern influenced by the characteristics of discontinuity distributions were also discussed. A multiple system for analyzing the feature of geometrical distribution of rock joints was furthermore developed. The results revealed that the orientation, position and density of discontinuities around a cavern influence its deformational behavior and stability significantly.
  • Yukiyasu FUJII, Manabu TAKAHASHI, Shinzaburo HORI
    2007 年 3 巻 1 号 p. 31-36
    発行日: 2007/12/01
    公開日: 2014/01/11
    ジャーナル フリー
    Fractures parallel to rift, grain and hardway planes of Inada granite were produced by a uni-axial tensile test. The obtained surface topography was analyzed by digital stereo-photogrammetry. A pair of photograph was taken by a digital camera with a macro lens mounted on a copy stand system. The measurement accuracy is about 0.02 mm parallel to the fracture surface, and 0.1 mm in the vertical direction, for the specimen of 30 mm diameter. From the results of calculation of roughness parameter, the fracture parallel to the rift plane is the smoothest, and the fracture parallel to the grain plane is smoother than the fracture parallel to the hardway plane.In addition, we discussed the applicability of the digital photogrammetric technique to other geo-engineering and geological objects.
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