击实膨胀土的循环膨胀特性研究

Approach to cyclic swelling behavior of compacted expansive clays

主要研究了干湿循环对击实膨胀土胀缩特性的影响。研究结果表明，击实膨胀土的胀缩变形并不是完全可逆的，随干湿循环的发展，膨胀土的膨胀速率加快，绝对膨胀率总是增大而相对膨胀率则降低。这种变化在第Ⅱ、Ⅲ级循环时最明显，第Ⅲ级循环后便趋于稳定。这些变化特性主要是粘粒集聚、微结构改变的结果。

The cyclic swelling behavior of compacted expansive clays is discussed in this paper. It shows that the swelling shrinkage behavior of expansive clays is not completely reversible. The experimental data indicate that upon repeated wetting and drying, the swelling rate of soils becomes faster. And every cycle results in decreasing swelling ability although the total swell percent increases. Furthermore it is noted that the second and third cycles cause the major reduction in swelling potential as the number cycles increases, and the soils reach the equilibrium in which no more reduction of swelling potential is caused. Finally, the authors consider that these properties are related to the integration of clay particles and the rearrangement of microstructure.