摘要
假设黄土垂直节理形成分为2个阶段,通过野外现场考察、室内物理模拟试验,结合黄土的湿陷性和裂隙产生的力学机理对黄土垂直节理的成因做出了探讨。结果表明黄土垂直节理的形成可分为2个阶段:①内裂隙形成阶段,开始沉积时,由于地形的起伏导致黄土厚度上的分布不均匀,在降雨时产生不均匀湿陷,从而导致产生内裂隙;②裂隙扩展阶段,内裂隙形成后黄土继续堆积,顶部压力的增长致使裂隙顶部土体受到拉应力作用,当达到其抗拉强度时裂隙就会沿竖直方向产生扩张而形成垂直节理。同时,通过实地考察,证实了假设是合理的。
At first, this paper proposes an assumption that the formation of loess vertical joints could be divided into two stages. On the basis of the field visits, indoor physical simulation tests, then in combination with loess collapsibility and the mechanical mechanism of producing fissures, the causes of the vertical joints of loess are explored. The results indicate that the formation of loess vertical joints can be divided into two phases ： （1）the formation of inner fissure, i.e. in the beginning of deposition, the undulation of terrain leads to uneven distribution of loess, then when it rains uneven collapsibility generates, which leads to generate inner fissures; （2）the stage of fissure extension, namely loess continues deposition after the inner fissures have been formed, the increasing of the top pressure makes the top of inner fissure lie in the state of tensile stress, so, when the stress reaches its tensile strength, the inner fissure extends along the vertical direction and then becomes a vertical joint. In the meantime, from survey in site, the rationality of assumption has been proved.
出处
《长江科学院院报》
CSCD
北大核心
2010年第3期38-41,45,共5页
Journal of Changjiang River Scientific Research Institute
关键词
黄土湿陷性
垂直节理
裂隙扩展
物理模拟试验
loess collapsibility
vertical joint
crack extension
physical simulation test
