关键词: 结构性黏土, 孔隙, 压汞试验, 固结压力, 分形维数

Abstract: Mercury injection test on Zhanjiang natural soft clay and compressed soil is conducted to obtain the microscopic deformation mechanism of structured soft clay. Evolutions of pore distribution, size, and structural characteristic parameters under different consolidation pressures are analyzed; the pore morphology is further quantitatively analyzed by SEM image, which is explained and testified by fractal theory. The results show that, a positive correlation is shown between the sensitivity of each pore size to external forces and pore volume content. The distribution density of the fine pores might be exaggerated while the one of macro pores might be underestimated in mercury injection test for the bottleneck effect. Pore distribution is affected by structure. When consolidation pressure increases to yield pressure, pores of 0.01-0.50 μm are changing obviously, pore connectivity becomes worse, pore size decreases, isolated pores increase, and limits between pore sizes become unobvious. Zhanjiang soft clay has multi-fractal characteristics, the limits for determining micro-pores, interparticle pores and isolated pores are 0.01 μm and 0.50 μm. Pore size division standard is given.

Key words: structural clay, pore, mercury injection test, consolidation pressure, fractal dimension