Micaceous sand has been found in the southwest coastal areas of Taiwan, but geotechnical properties of such sand have not been established. This paper presents the results of an investigation on both compressibility and shear strength of micaceous sand samples. Both natural micaceous sand and micaceous sand mixtures were prepared for laboratory tests. The conventional oedometer was used to measure compressibility and the direct shear apparatus was used to measure shear strength. Of particular interest is the time-dependent compressibility of micaceous sand. Both saturated and dry sand samples were used for the oedometer tests. The shear strength was measured on dry sand samples.
This paper presents the results of a laboratory testing program on both natural micaceous sand and laboratory prepared micaceous sand mixtures. The natural micaceous sand samples were taken from a mega coastal reclamation site in Mai-Liao, Taiwan. The reclaimed land has been open to use for industrial purposes, but excessive settlement of some important structures on the reclaimed land has been observed out of expectation. The location of the reclaimed land is at the seaward fringe of a wide alluvial fan of a major river. Seasonal flood and yearly occurring typhoon caused severe erosion problems in the upstream of the river, where fragments of metamorphic rocks containing mica were transported and broken apart in the river until resting in the alluvial fan. Limited studies have indicated the presence of mica (muscovite) in this alluvial sand deposit. Recent investigation by the author found that the Mai-Liao micaceous sand samples contained about 10% of Muscovite by weight. In view of the lack of data on the geotechnical properties of the Mai-Liao micaceous sand, both oedometer and direct shear apparatus were used in this study to investigate its compressibility and shear strength characteristics.