长江科学院院报 ›› 2017, Vol. 34 ›› Issue (6): 76-80.DOI: 10.11988/ckyyb.20160251

• 岩土工程 • 上一篇    下一篇

热湿作用下三峡库区典型砂岩劣化效应研究

王乐华1,2,金晶1,赵二平1,2,宛良朋3,邓华锋1,2   

  1. 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;
    2.武汉大学 水利水电学院,武汉 430072;
    3.中国三峡建设管理有限公司 乌东德建设部,昆明 651500
  • 收稿日期:2016-03-18 修回日期:2016-04-13 出版日期:2017-06-01 发布日期:2017-06-19
  • 作者简介:王乐华(1977-),男,安徽怀宁人,教授,博士,主要从事岩土工程方面的教学与研究工作,(电话)13986811749(电子信箱)lehuatg@126.com。
  • 基金资助:
    国家自然科学基金项目(51309141);国家重点研发计划项目(2016YFC0402003);水利部公益性行业科研专项经费项目(201401029);三峡大学土木与建筑学院2015年硕士创新基金资助项目(2015CX031)

Degradation of Typical Sandstone from the Three Gorges Reservoir under the Action of Alternate Drying and Wetting Cycles

WANG Le-hua1,2, JIN Jing1, ZHAO Er-ping1,2, WAN Liang-peng3, DENG Hua-feng1,2   

  1. 1.Key Laboratory of Geological Hazards on Three Gorges Reservoir Area of Ministry of Education, China Three Gorges University, Yichang 443002, China;
    2.School of Water Resource and Hydropower, Wuhan University, Wuhan 430072, China;
    3.Wudongde Engineering Construction Department, China Three Gorges Construction Management Co., Ltd., Kunming 651500, China
  • Received:2016-03-18 Revised:2016-04-13 Online:2017-06-01 Published:2017-06-19

摘要: 针对取自三峡库区范家坪滑坡砂岩,采用室内模拟高温季节环境条件,研究砂岩在“烘干-吸水”循环作用下的热湿效应,包括砂岩的质量劣化和抗剪强度参数的变化。结果表明①经历“烘干-吸水”热湿循环作用后,岩石质量劣化速率和吸水率是非线性波动变化的,其波动特征体现出了岩石内部裂隙的动态发育;②砂岩的抗剪强度参数黏聚力c和内摩擦角φ随着“烘干-吸水”热湿循环次数的增加而不断降低,在循环初期参数折减幅度较大,后期变缓并逐渐趋于稳定,这与岩石质量劣化规律具有相似性;③提出通过岩石直剪破坏裂纹延伸角度,定性判断岩石强度的方法。研究成果对昼夜温差大且气候潮湿的华中地区岩石劣化预测具有实际意义。

关键词: 砂岩, 烘干-吸水, 直剪试验, 裂隙发育, 直剪破坏模式, 热湿循环, 岩石质量劣化

Abstract: The degradation of sandstone, including mass degradation and variation of shear strength parameters, under the action of cyclic drying and water adsorption in high temperature season was simulated in laboratory. Sandstone samples were taken from Fanjiaping landslide in the Three Gorges Reservoir. Results indicate that 1) mass degradation rate and water adsorption rate fluctuated non-linearly under drying and wetting cycles, reflecting the dynamic development of fractures in the sandstone; 2) cohesion c and internal friction angle φ of sandstone reduced by a large margin in the initial stage of drying-wetting cycles, and then reduced steadily in the later stage, which is similar with the mass degradation law; 3) a method of determining the strength of sandstone in quantitative sense according to the extension angle of direct shear failure cracks was proposed. The research results are of practical significance to predicting rock deterioration in central China with humid climate and large temperature difference between day and night.

Key words: heating and water absorption, direct shear test, fracture development, direct shear failure mode, drying-wetting cycle, degradation of rock quality

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