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Abstract A series of unconfined compression tests were conducted on compacted loess samples with different structures at the same dry density and experimental water content. Based on the stress-strain curves of unsaturated and saturated compacted loess，the initial quantitative parameter was defined to describe the maximum overall structure potential before the start of the structural damage of the compacted loess. The influence of different structures caused by the change of molding water content on the stress-strain and strength characteristics as well as the structural parameter was investigated for the compacted loess with different experimental water contents. The results indicated that the molding water content affected the structure and the unconfined compressibility of unsaturated compacted loess，but had little influence on that of saturated compacted loess. The degree of influence decreased with the increase of water content. The plastic limit was found to be the critical value. When the experimental water content was smaller than the plastic limit，the influence was greater. The unconfined compressive strength and the initial structural parameter increased notably with the increase of the molding water content at the same experimental water content and decreased significantly with the increase of experimental water content at the same molding water content. The group of curves describing the relationships of the unconfined compressive strength versus the molding water content and the experimental water content was normalized into a nonlinear relationship with the initial structural parameter. The normalized nonlinear relationship described the influence of molding water content and experimental water content on the structure of compacted loess. Together with the grain size and the density，it described reasonably the mechanical properties of compacted soil.
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Received: 16 September 2013
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2014, Vol. 33 
