基于分形理论的堤防软基固结SEM分析——以长江江西济益公堤为例

SEM analysis of embankment soft foundation based on fractal theory:a case study of Jiyigong Embankment of Yangtze River in Jiangxi Province

研究软基堤防固结沉降特性对于增强沿江沿湖安全保障,具有十分重要的意义。而软基堤防加固的关键是从软土的结构特征揭示影响软土变形和强度的成因。以长江江西九江济益公堤软土地基为研究对象,结合河湖相沉积软土的物理力学性质和微观结构特征,利用PCAS软件分析了不同固结压力下软土SEM图像的定量参数。通过室内试验和理论分析,对河湖相沉积软土的微观结构与宏观力学性能进行了系统的分析。并对河湖相沉积软土的结构强度和工程效果进行了分析论证。提出了孔隙结构因子作为综合参数,利用分形评价理论对孔隙结构强度和破坏趋势进行综合参数测量。同时求解预固结压力,可以定量确定土体的结构强度,该方法对湖相软土的固结变形计算具有参考意义。

It is of great significance to study the consolidation and settlement characteristics of soft foundation embankment for strengthening the security guarantee along the river and lake. Taking Jiyigong soft soil foundation in Jiujiang City,Jiangxi Province as the research object,combining the physical and mechanical properties with microstructure characteristics of fluvial and lacustrine sedimentary soft soil,we analyze the quantitative parameters of SEM images of soft soil under different consolidation pressures with PACS software. Through laboratory test and theoretical analysis,the microstructure and macroscopic mechanical properties of fluvial and lacustrine sedimentary soft soil are systematically analyzed. The structural strength and engineering effect of fluvial and lacustrine sedimentary soft soil are analyzed and demonstrated. The fractal evaluation theory is used to measure the strength and failure tendency of pore structure. The structural strength of lacustrine soft soil can be quantitatively determined by solving the pre-consolidation pressure,which is of reference significance in calculating consolidation deformation of lacustrine soft soil.