植被发育斜坡土体干缩裂缝发育规律的实验研究

Experimental Study about Development Regularity of Vegetated Slope Soil Shrinkage Crack

为了得到斜坡非饱和带土体失水过程中干缩裂缝的发育规律,实验室条件下,将不同粒度组成的四组植被发育斜坡非饱和带土样饱和以后恒温失水,获取裂缝形成和发展过程中形态特征,并计算分析其裂隙率和裂缝盒维数的变化规律;基于Image J软件计算裂缝发育稳定时被裂缝切割形成的块区个数和各块区面积。研究结果表明:在裂缝发育过程中,土样的裂隙率和盒维数呈上升的趋势,且两者呈显著正相关关系,裂隙率总体上符合三阶段变化规律;颗粒组分越粗,裂缝发育越缓慢,其盒维数越小,裂缝形态相对规则;裂缝发展稳定时裂缝块区面积分布范围越广,块区面积越不均匀,裂缝切割土样形成块区个数越少。本文仅主要考虑了土样颗粒组成对裂缝发育的影响,其他影响因素有待进一步试验分析。

For the research on development regularity of vegetated slope soil shrinkage crack,four soil samples of different particle composition were saturated and then lost water with constant temperature under laboratory conditions. We calculated the crack ratio,box-counting dimension and the changing process between two former and moisture content by means of images acquisition in the process of shrinkage crack development. Furthermore,we calculated the block quantity and block area formed by crack trace based on Image J software. The results showed that the crack ratios,box-counting dimensions were increased and there are positively correlated with each other.Moreover,the increase pattern of crack ratios could be divided into three stages. In addition,the development velocity of shrinkage crack is slower and the value of box-counting dimension is smaller when the content of coarse grain component is higher,and then there a more wide range of block area which means block size more heterogeneous and the sum of block area is lesser according to the block quantity and block area analysis. Finally,it＇s necessary to note that in this paper we just consider the influence of grain composition. The others will be analyzed in further study.