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您的检索式：作者名="HE JiangDa"
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| 1 | Prediction Research of Deformation Modulus of Weak Rock Zone under In-situ Conditions显示文摘Weak rock zone (soft interlayer, fault zone and soft rock) is the highlight of large-scale geological engineering research. It is an important boundary for analysis of rock mass stability. Weak rock zone has been formed in a long geological period, and in this period, various rocks have undergone long-term consolidation of geostatic stress and tectonic stress; therefore, under in-situ conditions, their density and modulus of deformation are relatively high. Due to its fragmentary nature, once being exposed to the earth's surface, the structure of weak rock zone will soon be loosened, its density will be reduced, and its modulus of deformation will also be reduced significantly. Generally, weak rock zone can be found in large construction projects, especially in the dam foundation rocks of hydropower stations. These rocks cannot be eliminated completely by excavation. Furthermore, all tests nowadays are carried out after the exposure of weak rock zone, modulus of deformation under in-situ conditions cannot be revealed. In this paper, a test method explored by the authors has been introduced. This method is a whole multilayered medium deformation method. It is unnecessary to eliminate the relatively complete rocks covering on weak rock zone. A theoretical formula to obtain the modulus of deformation in various mediums has also been introduced. On-site comparative trials and indoor deformation modulus tests under equivalent density conditions have been carried out. We adopted several methods for the prediction researches of the deformation modulus of weak rock zone under in-situ conditions, and revealed a fact that under in-situ conditions, the deformation modulus of weak rock zone are several times higher than the test results obtained after the exposure. In a perspective of geological engineering, the research findings have fundamentally changed peoples' concepts on the deformation modulus of weak rock zone, provided important theories and methods for precise definition of deformation modulus of deep weak rock zone under cap rock conditions, as well as for reasonable engineering applications. | ZHANG Yong HE JiangDa WEI Yufeng NIE Dexin | 2011 | Journal of Mountain Science2011，8，2： | 3 |
| 2 | A discrete element exploration of V-shaped breakout failure mechanisms in underground opening显示文摘V-shaped breakouts,which may appear in underground opening during excavation,are the results of two different failure mechanisms:tensile spalling and shear fracturing.This study uses discrete elements in exploring the conditions that would lead to different breakout mechanisms under plane strain conditions.The test tunnel of the Mine-by Experiment in Lac du Bonnet granite batholith is adopted as the base problem.In order to carry out the study,some fundamental issues need to be addressed.First,an exponential softening bond that enables the incorporation of fracture energy is adopted.In order to obtain a reasonable ratio between the uniaxial compressive strength,rc,and the uniaxial tensile strength,rt,discrete disc particles are tied together to form an irregular shape clump as the basic discrete element.This effort is supported by a successful reproducing of test results from Lac du Bonnet granite in DEM modeling.The issue of sensitivity of discrete particle size on results is examined.The reduction of strength with increase in specimen size is also modeled.After the calibration work is completed,the Mine-by tunnel behavior is studied.Finally,this study shows that a reduction in rc/rt ratio,under the same setup,would cause the failure mechanism to transit from tensile spalling to shear fracturing in V-shaped breakouts. | Huaizhong Liu Jeen-Shang Lin Jiangda He Hongqiang Xie | 2020 | Underground Space2020，5，4： | 0 |
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