报告题目：Recent study on shear behavior of rock joints at Seoul National University
专家姓名宋在濬Song Jae-Joon 博士;韩国 首尔国立大学 副教授
报告时间：2014年12月19日（星期五）上午10：00-12：00
报告地点：老校部348学术会议室
邀 请 人：土木工程研究所 王述红

报告内容摘要
   This presentation introduces recent study on shear behavior of rock joints in Rock Mechanics & Rock Engineering Laboratory of Seoul National University. The first topic is ‘model for the shear behavior of rock joints under CNL and CNS conditions’. Empirical models for the shear behavior of rock joints are suggested from the results of direct shear tests using a servo-controlled shear testing machine. Cement mortar replicas of rock joints are tested while varying the normal stiffness, initial normal stress, joint roughness coefficient and joint wall compressive strength. The suggested models can be applied to predict the shear behavior of rock joints, including pre-peak and post-peak shear stress levels, regardless of the loading condition. The predictions of the suggested models corresponded well with the experimental results for the overall stress levels.
   The second topic is ‘determination of contact areas of a rock joint under normal and shear loads’. The joint surface is modeled as a group of triangular planes, and the contact condition of each plane is examined by calculating the relative displacements of both surfaces from their initial locations. To characterize the roughness of the joint surface including the contact area, the concept of ‘active and inactive micro-slope angle’ was defined based on the apparent inclination of the triangular element to the shear direction. The proposed method was applied to estimation of the distribution of aperture size within a rock joint.
The third topic is ‘a constitutive model for shear behavior of rock joints based on 3-D quantification of joint roughnesses. The model was developed using an empirical approach based on the results of a total of 362 direct shear tests on tensile fractured rock joints and replicas of tensile joints and on a new quantitative roughness parameter. This model can be used to predict the shear behavior under CNS as well as CNL conditions. The shear behavior obtained from the experimental results is generally in good agreement with that estimated by the proposed model, and the effects of joint roughness, initial normal stress, and normal stiffness are reasonably reflected in the model.

报告人简介
   宋在濬 Song Jae-Joon博士，现为韩国首尔国立大学 能源与资源学院副教授。2000年3月在韩国首尔国立大学获得博士学位,2000年5月-2002年5月在日本National Institute of Advanced Industrial Science and Technology(AIST)从事博士后研究。曾任韩国岩石力学学会秘书长、国际岩石力学学会非连续专业委员会韩国主席等。主要从事非连续岩石力学及其破坏机理方面的研究。研究方向包括块体理论、实验岩石力学、统计岩体力学等，主持韩国科学工程基金会等大型国家级项目多个，在《Rock Mechanics and Rock Engineering》、《International Journal of Rock Mechanics and Mining Sciences》等国际学术期刊杂志上发表学术论文40多篇，多次获得韩国岩石力学学会科技方面奖励。Song教授是国际非连续岩石力学界活跃学者。
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