中文核心期刊
CSCD来源期刊
中国科技核心期刊
RCCSE中国核心学术期刊

重庆交通大学学报(自然科学版) ›› 2016, Vol. 35 ›› Issue (4): 70-74.DOI: 10.3969/j.issn.1674-0696.2016.04.15

• 港口航道·水利水电·资源环境 • 上一篇    下一篇

超固结膨胀土抗剪强度特性及边坡稳定研究

吴珺华1,2,杨松3   

  1. (1. 南昌航空大学 土木建筑学院,江西 南昌 330063;2. 重庆交通大学 水利水运工程教育部重点实验室,重庆 400074;3. 云南农业大学 水利学院,云南 昆明 650201)
  • 收稿日期:2015-10-15 修回日期:2015-11-24 出版日期:2016-08-20 发布日期:2016-08-20
  • 作者简介:第一作者:吴珺华(1985—),男,江西吉安人,副教授,博士,主要从事土力学及边坡稳定方面的研究。E-mail:wjh0796@163.com。
  • 基金资助:
    国家自然科学基金项目(51408291);江西省教育厅科技项目(GJJ14547);江西省交通运输厅重点科技项目(2013C0006);重庆交通大学国家内河航道整治工程技术研究中心暨水利水运工程教育部重点实验室开放基金项目(SLK2014B01)

Study on Shear Strength Property of Over-consolidated Expansive Soil andSlope Stability

WU Junhua1,2, YANG Song3   

  1. (1. College of Civil Engineering and Architecture, Nanchang Hangkong University, Nanchang 330063, Jiangxi, P.R. China;2. Key Laboratory of Hydraulic and Waterway Engineering of the Ministry of Education, Chongqing Jiaotong University, Chongqing 400074, P.R.China; 3. College of Water Conservancy, Yunnan Agricultural University, Kunming 650201, Yunnan, P.R.China)
  • Received:2015-10-15 Revised:2015-11-24 Online:2016-08-20 Published:2016-08-20

摘要: 天然膨胀土经历长期干湿循环,反复胀缩使其具有超固结性。首先制取了超固结比为1.5的重塑膨胀土三轴样,进行了三轴排水剪切试验,获得了土体的峰值抗剪强度和残余抗剪强度;根据广义塑性剪应变的定义,采用硬化软化型函数建立了抗剪强度发挥值与广义塑性剪应变的函数关系,并引入到FLAC3D中的应变硬化/软化本构模型中,结合强度折减法进行了超固结膨胀土边坡的稳定性分析。结果表明:对于正常固结膨胀土,广义塑性剪应变很小,可采用稳定系数来评价边坡的稳定性;对于超固结膨胀土,应采用广义塑性剪应变和稳定系数来综合评价边坡的稳定性。如果广义塑性剪应变很大,即使稳定系数大于1,此时边坡也发生失稳破坏,说明土体的超固结性对膨胀土边坡的强度和变形影响不可忽略。

关键词: 岩土工程, 膨胀土, 超固结, 广义塑性剪应变, 抗剪强度, 边坡稳定

Abstract: Natural expansive soil acquires the property of over-consolidation through long term drying-wetting cycles. The remolded triaxial samples of expansive soil with the OCR 1.5 were prepared. The triaxial drained tests were carried out and the peak shear strength and residual shear strength were obtained. Hence,the relationship between the generalized plastic shear strain and exertions of shear strength was established using hardening-softening function. This function was introduced into the strain-hardening/softening constitutive model in FLAC3D and the over-consolidated expansive soil slope stability was analyzed combined with strength reduction method. The results showed that the normal-consolidated expansive soil slope stability could be evaluated by stability coefficient because of smaller generalized plastic shear strain; the over-consolidated expansive soil slope stability should be comprehensively evaluated by both generalized plastic shear strain and stability coefficient. The slope failure may happen because generalized plastic shear strain is so big although the stability coefficient is greater than one. The over-consolidation of expansive soil affects the strength and deformation obviously and should not be neglected.

Key words: geotechnical engineering, expansive soil, over-consolidation, generalized plastic shear strain, shear strength, slope stability

中图分类号: