软板岩膨胀特性试验及微观机制分析

发布时间：2018-08-20 09:27

【摘要】：针对软板岩内部特殊的构造及其遇水膨胀的特点,以湖南省怀化芷江地区的板岩为例,选取14组岩样分别进行矿物成分、微观结构测试和侧向约束膨胀试验,研究软质板岩的膨胀特性及其微观机制。结果表明:软质板岩侧向约束膨胀率与吸水时间之间呈指数函数关系,在试验早期,侧向约束膨胀率随吸水时间的延长而增大,且增长速率较快,侧向约束膨胀率-吸水时间关系曲线较陡;在试验后期,侧向约束膨胀率趋于稳定,侧向约束膨胀率-吸水时间关系曲线由陡变缓。侧向约束膨胀率随着吸水率的增长呈乘幂函数关系增长,在试验早期增长较快,而后增长速率变小,直至最后趋于稳定。轴向膨胀率随轴向荷载的增加呈负对数函数减小,初期减小幅度较大,后期逐渐变低。结构面方向和试样轴向的夹角α在区间[0°,90°]之间变化时,极限侧向约束膨胀率随着夹角α的增大而减小。
[Abstract]:In view of the special structure inside soft slate and its characteristics of water expansion, taking slate in Huaihua Zhijiang area of Hunan Province as an example, 14 groups of rock samples were selected to carry out mineral composition, microstructure test and lateral confined expansion test. The swelling characteristics and microscopic mechanism of soft slate are studied. The results show that the lateral confined expansion ratio of soft slate is exponentially related to the water absorption time. In the early stage of the experiment, the lateral confined expansion ratio increases with the increase of water absorption time, and the increase rate is relatively fast. The curve of the relationship between the lateral confined expansion rate and the water absorption time is steep, and in the later stage of the experiment, the lateral constrained expansion ratio tends to be stable, and the curve of the lateral constrained expansion ratio and the water absorption time curve changes from steep to slow. With the increase of water absorption, the lateral confined expansion increased with the increase of water absorption, and increased rapidly at the early stage of the experiment, then became smaller, and finally became stable. With the increase of axial load, the axial expansion ratio decreases with negative logarithmic function, and decreases greatly at the initial stage and gradually decreases at the later stage. When the direction of the structural plane and the axial angle 伪 of the specimen change between the interval [0 掳to 90 掳], the limit lateral confined expansion rate decreases with the increase of the angle 伪.
【作者单位】：三峡大学三峡库区地质灾害教育部重点实验室;中国地质大学(武汉)工程学院;
【基金】：国家自然科学基金项目(No.41274230) 湖北省自然科学基金重点项目(No.2013CFA110) 三峡大学科学基金项目(No.KJ20130048)
【分类号】：TU45

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