基于室内模拟实验的软土固结沉降的分形几何

Fractal Geometry of Consolidation Settlement of Soft Soil Based on Simulation Experiment

为了能够比较准确、简便地计算及预测软土的沉降,在Terzaghi一维固结理论的基础上,结合分形几何理论对软土的沉降计算进行了探讨和研究。首先通过室内模拟实验,获得了不同固结时期试样的孔隙比e、沉降量以及扫描电镜照片(SEM图片);然后利用WD-5软件对SEM图片进行处理,并计算得到孔隙分布的分数维Df;最后建立起e与Df的函数关系,再结合Terzaghi一维固结理论建立了Df与固结度、沉降量的关系方程并计算得到相应的固结度及沉降量。经分析得出:Df随着沉降量的增加而减小;软土在固结沉降过程中在42.33h处有一个明显的拐点;利用Df建立的固结沉降模型计算的结果与试验实测的结果基本吻合。

A more accurate and simpler method is suggested to calculate and predict settlement of soft soil by analysis and evaluation of fractal geometry.In this paper,SEM,settlement and void ratio of samples in different consolidation periods are obtained by laboratory experiments.Software WD-5 is used to process the SEM images of samples in different consolidation periods based on the simulation experiment.And then the fractal dimension of pore distribution is obtained.Finally the relative equation is established between degree of consolidation and fractal dimension.The results show that fractal dimension of pores distribution decreases with the increasing of settlement.There is a clear turning point at the time of 42.33 h in the consolidation.Results of the calculation are basically agree with the measurement in tests.