冻融循环条件下原状黄土强度损伤试验研究

西安科技大学 建筑与土木工程学院,陕西 西安 710054

黄土; 冻融循环; 损伤; 弹性模量

Experimental study on strength damage of undisturbed loess under freeze-thaw cycles condition
LIU Hui,YANG Geng-she,YE Wan-jun,WEI Yao,TIAN Jun-feng

(College of Civil and Architectural Engineering,Xi'an University of Science and Technology,Xi'an 710054,China)

loess; freeze-thaw cycles; damage; modulus of elasticity

DOI: 10.13800/j.cnki.xakjdxxb.2016.0505

备注

受昼夜小周期及季节大周期交替气温循环作用的影响,黄土体的损伤对低温黄土工程建设的影响不可忽视。冻融循环过程对黄土体原生结构产生不可逆的改变,导致黄土物理力学性能劣化。开展阳曲高含水率黄土在冻融循环条件下的力学性能进行试验研究,通过分析黄土原生结构逐渐丧失和次生结构逐渐形成的过程,探讨了黄土体在加载和温度等因素作用下的变形发展规律,提出以冻融循环次数表示冻融损伤,用弹性模量定义损伤变量,描述冻融循环后黄土强度损伤演化。所提出的方法为正确评价黄土结构在冻融循环作用下损伤机理分析提供了科学依据。

Affected by alternating temperature cycling because of day and night cycle and seasonal cycle,loess engineering at low temperature will inevitably undergo problem of damage.Freezing and thawing cycles produce irreversible change in primary structure of loess.Moreover,it causes deterioration of physical and mechanical properties of loess.Experiment of loess with high water content was carried out to study its mechanical properties.By analysis the process of gradual loss of primary structure and formation of secondary structure,discussion on the development of deformation is done under the combined effect of freeze-thaw cycles and loads.It is proposed that freeze-thaw damage can represented in number of freeze-thaw cycles,and damage variable can defined by modulus of elasticity to describe damage evolution of loess strength.The method proposed in this paper provides scientific basis for damage mechanism analysis of structure of loess under the action of freezing and thawing cycles.