石灰改良膨胀土干缩裂隙发展规律研究

Research on Development Law of Shrinkage Cracks of Lime-treated Improved Expansive Soil

通过石灰改良膨胀土的室内干缩试验,采用图像处理技术和MATLAB编程技术精确提取膨胀土裂隙的特征参数。试验结果表明不同石灰掺量的改良膨胀土在干燥收缩过程中裂隙特征参数均先快速上升,在达到峰值之后开始缓慢下降,最终在5d附近趋于稳定;经过石灰改良后的膨胀土裂隙特征参数峰值出现较早,且峰值和残余值有明显的减小,但过量的石灰对膨胀土干缩拟制不明显。文章利用电镜扫描技术对石灰改良膨胀土进行了微观分析,并解释了膨胀土干缩的力学机理。

After designing interior drying shrinkage experiments on lime-treated expansive soil,in which the Technique of image processing and MATLAB Programming is applyed to extract characteristic parameters of cracked image of expansive soil. The results show that characteristic parameters of cracked image of expansive soil improved in different lime dosage in during dring first increases rapidly and began to slowly decrease after near the peak,in final stabilized at fifth day. The peak of lime-treated expansive soil characteristic parameters of cracked image appeared earlier,and the peak and residual values were reduced. It's is not obvious to drying shrinkage of expansive soil with the lime increased. Electron microscopy analysis technique is applyed to analyze the lime-treated expansive soil microscopically and explained mechanical mechanism of drying shrinkage of expansive soil.