Strength and deformation characteristics of compacted loess with different moisture content and compaction energy

Abstract

The normal operation of superstructure in loess areas will be related closely to the strength and stability of compacted loess. Loess samples derived from two different engineering sites in China were compacted with different compaction energy, and the main factors which will affect the strength and deformation of compacted loess were analyzed. Different soil samples were prepared with varying moisture content of 11 %–19 %. As the moisture content increases, the compression deformation of compacted loess increases. The immersion influence coefficient suitable for compacted loess was calculated in this study. During soaking in water for 4 days, the California Bearing Ratio (CBR) decreases gradually. Especially, in the process of soak, the lower the initial moisture contents of sample, the more obvious the CBR degradation of sample. It is suggested that soil should be compacted with appropriate compaction energy and moisture content. Furthermore, the loess should be compacted under the condition that the moisture content is slightly greater than the optimal moisture content. When the current moisture content is about 1.02 times the optimal value, the compaction performance of loess is better. As disclosed in this research, the compacted loess in optimal compaction state has smaller compression deformation, better stability and weaker sensitivity to saturation.

Keywords

• Compacted loess
• Compaction energy
• Moisture content
• Compressive deformation
• CBR strength
• Shear strength