干湿循环作用下非饱和重塑黏土变形特性研究

为了研究了基质吸力与干湿循环对非饱和重塑黏土压缩变形特性的影响,利用最新研制的全自动非饱和土固结仪,在控制基质吸力的条件下进行非饱和土压缩试验。研究结果表明,吸力越大,土体的压缩性越小,屈服应力越大,含水率减小的幅度也越小。试样经历干湿循环后,土体的压缩性增大,屈服应力减小,土体弹性变形的应力范围也减小。非饱和土的压缩变形以孔隙气体的压缩为主,土体中孔隙水的排出处于次要地位。干湿循环对非饱和土变形特性有重要影响,考虑其影响对于实际工程应用是十分必要的。

Experimental Study of Wetting-Drying Cycle on Deformation Behaviors of Unsaturated Remoulded Clay

In order to study the deformation rules of unsaturated remoulded clay under matric suction and wetting-drying cycle, compression tests are carried out under controlled matric suction condition with the newest-developed automatic unsaturated soil consolidation instrument. The results show that the larger the suction, the smaller the comprehensibility of soil, the larger the yield stress, and the smaller the decrease of water content. After the dry-wet cycle, the comprehensibility of soil increases, the yield stress decreases, and the stress range of elastic deformation decreases. The compression deformation of unsaturated soil is dominated by the compression of pore gas, and the drainage of pore water is secondary. Wetting-drying cycle has an important influence on deformation behaviors of unsaturated soil and it's necessary to appreciate this influence in the practical projects.