氯化钠侵蚀环境下固化疏浚土宏微观力学特性试验

为研究固化疏浚土在氯化钠侵蚀环境下的工程特性,以上海市南汇东滩某吹填场地的黏质粉土为试验土料,掺入自制固化剂制备固化疏浚土试块,进行氯化钠浸泡试验,研究氯化钠初始质量浓度和浸泡龄期对试块抗压强度的影响。采用扫描电镜拍摄试块表面微观结构照片;采用Image-Pro Plus (IPP)图像处理技术结合MATLAB分析程序得到与颗粒和孔隙相关的微观结构参数;基于分形理论,研究氯化钠初始质量浓度、分形维数和抗压强度三者之间的宏微观关联。结果表明:试块的抗压强度随着氯化钠初始质量浓度和浸泡龄期的增长而增长;氯化钠初始质量浓度的增加会引起分形维数的变化,进一步影响试块的宏观抗压强度,三者之间存在内在的定量关联。

Macro-micro mechanical property test of solidified dredged soil under sodium chloride erosion environment

In order to study the engineering characteristics of solidified dredged soil under sodium chloride erosion environment, the solidified dredged soil specimen was prepared by adding the self made curing agent into the test soil (i. e. clay silt from a hydraulic filling site in Nanhui East Shoal, Shanghai), and the sodium chloride immersion test was carried out to study the effects of the sodium chloride initial mass concentration and the immersion age on the compression strength of the specimen. The surface microstructure of the specimen is captured using the scanning electron microscope, and the microstructure parameters related to particles and pores are obtained by Image Pro Plus (IPP) image processing technique and MATLAB analysis program. Based on the fractal theory, the macro and micro correlation among the sodium chloride initial mass concentration, the fractal dimension and the compression strength is studied. The results show that: the compression strength of the specimen increases with the increase of the sodium chloride initial mass concentration and the immersion age; the increase of the sodium chloride initial mass concentration causes the change of the fractal dimension and further affects the macroscopic compression strength of the specimen, and there is an internal quantitative correlation among the three.