›› 2018, Vol. 39 ›› Issue (7): 2344-2352.doi: 10.16285/j.rsm.2017.0607

• 基础理论与实验研究 • 上一篇    下一篇

水-岩作用对砂岩卸荷力学特性及微观结构的影响

邓华锋,张恒宾,李建林,王晨玺杰,张吟钗,王 伟,胡亚运   

  1. 三峡大学 三峡库区地质灾害教育部重点实验室,湖北 宜昌 443002
  • 收稿日期:2017-04-04 出版日期:2018-07-10 发布日期:2018-08-05
  • 作者简介:邓华锋,男,1979年生,博士,教授,主要从岩土工程方面的教学与研究工作。
  • 基金资助:

    湖北省自然科学基金重点项目(No. 2015CFA140);国家自然科学基金资助项目(No. 51679127);国家自然科学基金重点项目(No. 51439003);三峡库区地质灾害教育部重点实验室(三峡大学)开放基金(No. 2015KDZ12)。

Effect of water-rock interaction on unloading mechanical properties and microstructure of sandstone

DENG Hua-feng, ZHANG Heng-bin, LI Jian-lin, WANG Chen-xi-jie, ZHANG Yin-chai, WANG Wei, HU Ya-yun   

  1. Key Laboratory of Geological Hazards on Three Gorges Reservoir Area, Ministry of Education, China Three Gorges University, Yichang, Hubei 443002, China
  • Received:2017-04-04 Online:2018-07-10 Published:2018-08-05
  • Supported by:

    This work was supported by the Natural Science Foundation of Hubei Province (2015CFA140), the National Nature Science Foundation of China (51679127) and the National Nature Science Foundation of China (51439003) and the Foundation of Key Laboratory of Geological Hazards on Three Gorges Reservoir Area (China Three Gorges University), Ministry of Education (2015KDZ12).

摘要: 库岸坡岩体在工程建设中不可避免要遭遇开挖卸荷作用的影响,以三峡库区典型岸坡的层状砂岩为试验对象,设计开展了模拟库水位升降变化和浸泡-风干循环的水-岩作用试验,重点分析了水-岩作用对砂岩卸荷力学特性和微观结构的影响。研究表明:在10次水-岩作用过程中,砂岩的三轴卸荷强度、抗剪强度总体呈先陡后缓的劣化趋势,前4次水-岩作用的劣化速度较快,占总劣化度的70%左右,而后,劣化趋势逐渐趋缓;随着水-岩作用次数的增加,同一围压下岩样卸荷前的变形模量逐渐降低,围压卸载过程中变形模量的线性缓变阶段逐渐变短,非线性突变阶段逐渐变长、变缓,岩样的脆性特征逐渐减弱,塑性逐渐增强;水压力的反复升降变化和浸泡-风干循环作用对岩样造成了不可逆的渐进累积损伤,微观上岩样微裂纹、裂隙、孔隙逐步发育、汇集,宏观上就表现为孔隙率增加、三轴卸荷强度、抗剪强度的劣化。相关研究结论可为库岸边坡岩体开挖卸荷变形稳定分析提供参考。

关键词: 库岸边坡, 水-岩作用, 卸荷, 劣化规律, 微观结构

Abstract: The bank slope of the reservoir is inevitably affected by the excavation unloading during the project construction. In this study, we selected sandstone from the typical bank slope in Three Gorges Reservoir Region. Water-rock cycle experiments were carried out to simulate the variation of water levels and immersion-air drying cycles. Especially, the water-rock interaction effect on unloading mechanical properties and microstructure of stratification sandstone was mainly analyzed. The results showed that in the course of ten times of water-rock cycles, the triaxial unloading and shear strength of sandstone presented initially a steep deterioration and later gradual deterioration trend. The first four times accounted for about 70% in the overall deteriorating degree, which indicated the degree in the last three cycles slowed down. As the water-rock cycle times increased, the deformation modulus of rock specimen decreased gradually before uploading at the same confining pressure. During the unloading process of confining pressure, the linear graded phase of deformation modulus gradually became shorter, whereas the nonlinear mutation phase became longer and slower. The brittle feature of rock specimen slowly weakened, whereas its plasticity enhanced. The repeated fluctuations in water pressure and the immersion-air drying cycle resulted in an irreversible slow and accumulated damage to the rock specimen. Microscopically, micro-cracks, cracks and pores of rock steadily developed and accumulated. Macroscopically, the porosity rate increased, and the triaxial unloading and shear strength decreased. This study can provide references for the analysis of excavation, unloading and deformation of slope rock mass in bank slopes.

Key words: bank slope, water-rock interaction, unloading, deteriorating rule, microstructure

中图分类号: 

  • TU 457

[1] 徐日庆, 程康, 应宏伟, 林存刚, 梁荣柱, 冯苏阳, . 考虑埋深与剪切效应的基坑卸荷下卧 隧道的形变响应[J]. 岩土力学, 2020, 41(S1): 195-207.
[2] 卞康, 陈彦安, 刘建, 崔德山, 李一冉, 梁文迪, 韩啸. 不同吸水时间下页岩卸荷破坏特征的 颗粒离散元研究[J]. 岩土力学, 2020, 41(S1): 355-367.
[3] 赵怡晴, 吴常贵, 金爱兵, 孙浩, . 热处理砂岩微观结构及力学性质试验研究[J]. 岩土力学, 2020, 41(7): 2233-2240.
[4] 童星, 袁静, 姜叶翔, 刘兴旺, 李瑛, . 基于Mindlin解的基坑分层卸荷附加应力计算 及回弹变形的多因素影响分析[J]. 岩土力学, 2020, 41(7): 2432-2440.
[5] 姚宏波, 李冰河, 童磊, 刘兴旺, 陈卫林. 考虑空间效应的软土隧道上方卸荷变形分析[J]. 岩土力学, 2020, 41(7): 2453-2460.
[6] 毛浩宇, 徐奴文, 李彪, 樊义林, 吴家耀, 孟国涛, . 基于离散元模拟和微震监测的白鹤滩水电站左岸地下厂房稳定性分析[J]. 岩土力学, 2020, 41(7): 2470-2484.
[7] 侯公羽, 荆浩勇, 梁金平, 谭金鑫, 张永康, 杨希, 谢鑫, . 不同荷载下矩形巷道围岩变形及声发射 特性试验研究[J]. 岩土力学, 2020, 41(6): 1818-1828.
[8] 朱楠, 刘春原, 赵献辉, 王文静, . 不同应力路径下K0固结结构性黏土 微观结构特征试验研究[J]. 岩土力学, 2020, 41(6): 1899-1910.
[9] 赵军, 郭广涛, 徐鼎平, 黄翔, 胡偲, 夏跃林, 张頔. 三轴及循环加卸载应力路径下深埋 硬岩变形破坏特征试验研究[J]. 岩土力学, 2020, 41(5): 1521-1530.
[10] 孙银磊, 汤连生, 刘洁, . 非饱和土微观结构与粒间吸力的研究进展[J]. 岩土力学, 2020, 41(4): 1095-1122.
[11] 杜宇翔, 盛谦, 王帅, 付晓东, 罗红星, 田明, 王立纬, 梅鸿儒. 昔格达组半成岩微观结构与力学性质研究[J]. 岩土力学, 2020, 41(4): 1247-1258.
[12] 师旭超, 孙运德. 线性卸荷作用下软土超孔隙水压力 变化规律分析[J]. 岩土力学, 2020, 41(4): 1333-1338.
[13] 张善凯, 冷先伦, 盛谦, . 卢氏膨胀岩湿胀软化特性研究[J]. 岩土力学, 2020, 41(2): 561-570.
[14] 雷华阳, 胡垚, 雷尚华, 祁子洋, 许英刚, . 增压式真空预压加固吹填超软土微观结构特征分析[J]. 岩土力学, 2019, 40(S1): 32-40.
[15] 任青阳, 张黄梅, 刘佳申, . 两种卸荷路径下泥岩流变特性试验研究[J]. 岩土力学, 2019, 40(S1): 127-134.
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed   
No Suggested Reading articles found!