长江科学院院报 ›› 2017, Vol. 34 ›› Issue (6): 88-92.DOI: 10.11988/ckyyb.20160171

• 岩土工程 • 上一篇    下一篇

紫红色泥岩三轴蠕变力学特性试验研究

闫云明,李恒乐,郭士礼   

  1. 河南工程学院 资源与环境学院,郑州 451191
  • 收稿日期:2016-03-03 修回日期:2016-03-21 出版日期:2017-06-01 发布日期:2017-06-19
  • 作者简介:闫云明(1963-),男,山西临汾人,讲师,主要从事岩土工程的研究与工程实践,(电话)18603863633(电子信箱)zhangliqq134@163.com。
  • 基金资助:
    河南省教育厅攻关项目(2011A170001);河南省高等学校重点科研项目(15A170005,16A170009)

Experimental Study on Creep Mechanical Characteristics of Aubergine Mudstone under Three-dimensional Stress Conditions

YAN Yun-ming, LI Heng-le, GUO Shi-li   

  1. School of Resources and Environment, Henan University of Engineering, Zhengzhou 451191, China
  • Received:2016-03-03 Revised:2016-03-21 Online:2017-06-01 Published:2017-06-19

摘要: 为揭示泥岩在不同应力环境下的蠕变力学特性,对取自某在建工程的紫红色泥岩分别进行围压为0.5,1.0,2.0,5.0 MPa的分级加载蠕变试验。试验研究表明围压越大,泥岩的强度越大,塑性变形能力越强,流变特性越显著;相同围压下,稳态蠕变速率随偏应力呈幂指数函数型增长;相同偏应力下,稳态蠕变速率随围压升高而降低;利用等时应力-应变曲线法,得到泥岩的长期强度分别为11,16,22.5,29 MPa,均较各自围压下短期强度值降低40%~45%;通过摩尔强度准则得到的长期内聚力和内摩擦角分别为3.09 MPa和34.8°,分别较短期参数降低20.6%和25.9%。根据研究成果给出了一种带应变触发的分数阶蠕变本构模型,理论曲线与试验曲线拟合度良好,能较好地模拟泥岩的蠕变全过程。

关键词: 紫红色泥岩, 三轴蠕变, 稳态蠕变速率, 长期强度, 蠕变本构模型

Abstract: In the aim of obtaining the creep mechanical properties of mudstone under different stress environments, stepped loading creep test under confining pressure of 0.5 MPa, 1 MPa, 2 MPa, and 5 MPa was carried out on augergine mudstone from a project under construction. Results revealed that strength, plastic deformation ability and rheological properties of aubergine mudstone were greater and more significant with the increase of confining pressure; steady-state creep rate increased exponentially with the increase of deviatoric stress under the same confining pressure, and reduced with the increase of confining pressure under the same deviatoric stress. According to isochronous stress-strain curves, the long-term strength of aubergine mudstone was 11 MPa, 16 MPa, 22.5 MPa, and 29 MPa respectively, reduced approximately 40%~45% compared with the short-term strength under corresponding confining pressures; the long-term cohesion and internal friction angle were 3.09 MPa and 34.8° by Mohr strength criterion, decreasing by 20.6% and 25.9% compared with the short-term parameters. Furthermore, a fractional creep constitutive model with strain trigger was given to simulate the whole process of mudstone creep, and the theoretical curves fit well with experimental curves.

Key words: aubergine mudstone, triaxial creep, steady-state creep rate, long-term strength, creep constitutive model

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