Table 1

. Summary of average basic material properties

Upper BrownUpper BlackLower BrownLower Black
Moisture content (%)13.19.711.511.3
Bulk density (Mg m−3)2.2282.3372.2832.284
Liquid limit (%)29.328.330.029.5
Plastic limit (%)15.915.114.917.8
Plasticity index (%)13.413.215.111.8
Clay content (%)11.714.817.817.5
Silt content (%)17.024.728.330.5
Sand content (%)25.024.725.734.0
Gravel content (%)46.335.828.035.5