Based on direct shear tests on intact and remolded Angola Quelo/Muceque sand

the effects of structural characteristics

water content and dry density on the shear strength have been explored. The test results indicate that the structural characteristics have a relatively complex impact on the shear strength of the Quelo sand; and there are some significant differences in the shear strength parameters between intact and remolded samples. The water-weakening characteristics of the Quelo sand are remarkable; and the cohesion and the internal friction angle of intact and remolded samples tend to be approximately logarithmic attenuation with increasing the water content. The Quelo sand is well-graded and will achieve high shear strength after compaction

which is suitable to be used as backfill material. With increasing the dry density

the cohesion increases linearly and the internal friction angle can be divided into stabilizing section and increasing section

showing the characteristics of sub-functions.