采矿与安全工程学报 ›› 2016, Vol. 33 ›› Issue (2): 342-347.

• 论文 • 上一篇    下一篇

级配饱和破碎岩石压缩变形与分形特性试验研究

  

  1. 1.中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏 徐州 221116; 2.中国矿业大学力学与建筑工程学院,江苏 徐州 221116
  • 收稿日期:2015-06-14 出版日期:2016-03-15 发布日期:2016-04-22
  • 作者简介:郁邦永(1987—),男,江苏省邳州市人,博士研究生,从事采动岩体力学与破碎岩体渗流力学方面的研究。
  • 基金资助:

    国家重点基础研究发展计划(973)项目(2013CB227900);江苏省 2014 年度普通高校研究生科研创新计划项目(KYLX_1370);国家自然科学基金项目(51404266,51404262)

Experimental study on compaction and fractal characteristics of saturated broken rocks with different initial gradations

  • Received:2015-06-14 Online:2016-03-15 Published:2016-04-22

摘要: 综合利用 MTS816.03 试验系统与自制的破碎岩石压缩装置进行了不同岩性饱和破碎岩石的压缩试验,分析了岩性、轴向应力、粒径配比和加载速率 4 种影响因素下试样的压缩变形与分形特性。得出以下结论:1) 矸石、泥岩和砂岩试样的压缩过程相似且可分为 2 个阶段,即为 0~4 MPa 的快速变形阶段和 4 MPa 后的缓慢变形阶段;而灰岩试样的压缩过程变形速率均匀。2) 在相同粒径配比条件下,随着轴向应力的增大,砂岩分形维数单调增大,岩石颗粒破碎程度加剧。轴向应力与分形维数之间关系可用指数函数拟合。3) 在试样压缩过程中,Talbol 幂指数越大,试样轴向位移越大;加载速率越大,试样轴向位移越小。4) 在 12 MPa 轴向应力下,Talbol 幂指数越大,试样压缩后的分形维数增量越大,被压碎的岩石颗粒越多;加载速率越大,试样分形维数越大,破碎程度越低。

关键词: 粒径配比, 饱和破碎岩石, 压缩变形, 分形维数

Abstract: Using the MTS816.03 test system and self-designed compression apparatus for broken rocks, the compaction tests for saturated broken rocks with different lithologic have been conducted, and the influence of lithology, axial stress, initial gradations and loading rate on compaction deformation and fractal characteristics has been analyzed. The results have shown that:1) The compaction processes of gangue, mudstone and sandstone are similar and can be divided into two stages, including the rapid compaction deformation stage (0-4 MPa) and the slow compaction deformation stage (after 4 MPa). However, the compaction deformation rate of limestone is steady. 2) Under the same initial gradation, as axial stress increases, the fractal dimension of sandstone samples increases monotonously, and the breaking degree gets higher. The relations between fractal dimension and axial stress can be described by exponential function. 3) In the compacting process, as the Talbol exponent increases, the axial displacement increases. As the loading rate increases, the axial displacement decreases. 4) Under the same axial stress, 12 MPa, as the Talbol exponent increases, the increment of fractal dimension increases and the quantity of rock particles crushed increases. As the loading rate increases, the fractal dimension decreases, and the breaking degree gets lower.

Key words: initial gradation, saturated broken rocks, compaction deformation, fractal dimension