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冰川冻土 ›› 2016, Vol. 38 ›› Issue (4): 1150-1156.doi: 10.7522/j.issn.1000-0240.2016.0134

• 寒旱区重大工程问题 • 上一篇    下一篇

基于黄土结构损伤的地裂缝局部化破裂发展机制

佘芳涛1 2, 马纯阳1, 张俊岱3   

  1. 1. 西安理工大学, 陕西 西安 710048;
    2. 陕西省黄土力学与工程重点实验室, 陕西 西安 710048;
    3. 中铁隧道勘测设计院有限公司, 天津 300133
  • 收稿日期:2016-02-03 修回日期:2016-07-20 出版日期:2016-08-25 发布日期:2016-09-19
  • 作者简介:佘芳涛(1983-),男,安徽安庆人,讲师,2012年在西安理工大学获博士学位,现从事黄土力学与工程研究.E-mail:shefangtao@xaut.edu.cn
  • 基金资助:
    陕西省科技厅基金项目(2014JQ5173);陕西省教育厅基金项目(14JK1519)资助

Localized failure mechanism of ground fracture based on structural damage of loess

SHE Fangtao1 2, MA Chunyang1, ZHANG Jundai3   

  1. 1. Xi'an University of Technology, Xi'an 710048, China;
    2. Shaanxi Provincial Key Laboratory of Loess Mechanics and Engineering, Xi'an 710048, China;
    3. China Railway Tunnel Survey & Design Institute Co. Ltd., Tianjin 300133, China
  • Received:2016-02-03 Revised:2016-07-20 Online:2016-08-25 Published:2016-09-19

摘要: 针对西安地裂缝活动条件下黄土覆盖层裂缝的发展与形成,依据黄土的构度和应力比结构性参数变化规律,分析了黄土构度和抗拉强度之间的关系,建立了黄土结构性演变的数学模型,抗拉强度与抗剪强度随结构性参数变化强度准则,以及反映黄土结构性演变的Mohr-Coulomb屈服面弹塑性模型.通过本构模型嵌入FLAC3D软件,数值模拟西安地裂缝活动边界条件,以及结构性黄土地层结构,进行了黄土结构损伤变化和地层破裂带形成发展分析研究.表明地裂缝错动位移作用条件下,黄土地层塑形区域破裂带发展分为初始剪切破坏、初始拉伸破坏、剪切与拉伸破坏发展、破裂带贯通四个阶段;地层破裂带黄土的结构性损伤衰减变化突出,黄土应力比结构性参数等值线与地层塑性破裂带分布一致.揭示的黄土地层局部化破裂发展过程机制,对于认识地裂缝造成地面建筑物与地下工程灾害有重要的理论和实际意义.

关键词: 黄土, 结构损伤, 结构性参数, 地裂缝, 破裂带

Abstract: Stuctural damage and fracture of loess strata is caused by the activity of ground fracture. First, bsaed on structural index and stress ratio structural parameter, we establish mathematical model reflecting the initial structure of loess and evolution under coupling of stress and moisture, and analyse variation of tensile strength and compression-shear strength of loess with structure. Second, we establish M-C structure constitutive model of hyper elasto-plasticity which reflects structure evolution of loess. Third, the constitutive model is compiled by Fish language to accomplish inserting FLAC3D explicit finite-difference software. Finally, Stuctural damage and fracture of loess strata under acting ground fracture is very well simulated by the software, and we research on localized failure mechanism of ground fracture of loess strata. Research shows that the evolutionary process of ground fracture in loess zone divided into four stages: initial shear damage stage, initial tensile damage stage, tensile and shear failure development stage, failure surface through stage. Structural evolution of loess is very predominant in the process of progressive failure. The distribution of stress ratio structural parameter under acting ground fracture is consistent with the plastic zones. The results of the research have great significance both in theory sense and engineering practice to understanding the disasters of ground and underground buildings under acting ground fracture.

Key words: loess, structural damage, structural parameter, ground fracture, rupture zones

中图分类号: 

  • P694