东北大学学报(自然科学版) ›› 2024, Vol. 45 ›› Issue (4): 584-591.DOI: 10.12068/j.issn.1005-3026.2024.04.016

• 资源与土木工程 • 上一篇    

不同组构砂岩微观破坏特征分析

孙大增1, 赵文1, 许兴亮2, 王鑫1   

  1. 1.东北大学 资源与土木工程学院,辽宁 沈阳 110819
    2.中国矿业大学 煤炭资源与安全开采国家重点实验室,江苏 徐州 221116
  • 收稿日期:2022-12-08 出版日期:2024-04-15 发布日期:2024-06-26
  • 作者简介:孙大增(1994-),男,辽宁本溪人,东北大学博士研究生
    赵 文(1962-),男,内蒙古乌兰察布人,东北大学教授,博士生导师.
  • 基金资助:
    国家自然科学基金资助项目(51878127)

Microscopic Failure Characteristics of Sandstones with Different Composition and Microstructures

Da-zeng SUN1, Wen ZHAO1, Xing-liang XU2, Xin WANG1   

  1. 1.School of Resources & Civil Engineering,Northeastern University,Shenyang 110819,China
    2.State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology,Xuzhou 221116,China. Corresponding author: ZHAO Wen,E-mail: wenneu@163. com
  • Received:2022-12-08 Online:2024-04-15 Published:2024-06-26

摘要:

为了研究不同组构砂岩宏观-微观破坏特征的内在联系,对香花岭矿区三种砂岩开展物相分析、沉积相判别及单轴压缩和剪切试验,观察微观结构差异.研究结果表明:陆相沉积石英砂岩抗压强度最大,长石砂岩次之,海相沉积海绿石砂岩最小;单轴压缩试验宏观上石英砂岩、长石砂岩发生脆性破坏,而海绿石砂岩呈现出具有软化特性的延性破坏,微观上石英砂岩发生沿晶破坏,断面平整,长石砂岩发生沿晶和穿晶破坏,断面呈小扇贝状,表面附着少量碎屑,海绿石砂岩断面呈平板-花团复合状,晶粒破碎且擦痕明显,晶粒、胶结物质及结构弱面共同控制破坏特征;剪切试验微观上石英砂岩先发生沿晶破坏后发生穿晶破坏,断面不平整、擦痕及碎屑多,长石砂岩以沿晶破坏为主伴随穿晶破坏,断面部分平整、擦痕及碎屑较多,海绿石砂岩同时发生沿晶破坏和穿晶破坏,断面平整、几乎无擦痕和碎屑,砂岩微观破坏特征受晶粒和晶间胶结物质强度的共同影响.

关键词: 砂岩, 矿物组成, 微观结构, 破坏特征, 强度

Abstract:

In order to study the interconnection between macroscopic and microscopic failure characteristics of different textured sandstones, three types of sandstones from Xianghualing mining area were analyzed using petrographic analysis, sedimentary phase discrimination, and uniaxial compression and shear tests to observe the microscopic structural characteristics. The results show that compressive strength of terrestrial sedimentary quartz sandstone is the largest, followed by feldspathic sandstone, and marine sedimentary glauconitic sandstone is the smallest. In uniaxial compression, quartz sandstone and feldspathic sandstone exhibit brittle failure on a macroscopic scale, while glauconitic sandstone shows ductile failure with softening characteristics. On the microscopic scale, quartz sandstone undergoes intergranular failure with a smooth surface, while feldspathic sandstone experiences intergranular and transgranular failure with a small scallop?shaped surface and minimal adhering debris, and glauconitic sandstone displays a flat?granular composite fracture surface with obvious grain crushing and pronounced scratches. The failure characteristics are jointly controlled by the grains, cemented material and structural weak planes. The shear test microscopically shows that the quartz sandstone occurs has transgranular failure first and then intergranular failure, with uneven surface, scrapes and debris, while the feldspathic sandstone occurs transgranular failure mainly and intergranular failure, with partially flat surface, scrapes and debris. The glauconitic sandstone simultaneously exhibits intergranular and transgranular failure, resulting in a smooth surface with almost no abrasion or debris. The microscopic failure characteristics are influenced by the grain strength and cementing materials.

Key words: sandstone, mineral composition, microstructure, failure characteristics, strength

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