Engineering geology of residual soil derived from mudstone in Zimbabwe
2020
Zhang, Xianwei | Liu, Xinyu | Chen, Cheng | Kong, Lingwei | Wang, Gang
As increasing amounts of civil engineering work are carried out on mudstone-derived residual soils, it has become important to systematically assess their geological engineering properties. Thus, the properties of mudstone-derived residual soils were evaluated in this study via a series of comprehensive laboratory tests to assess physical, mechanical, mineralogical, and microstructural variations. Results show that the physical properties of these soils are inadequate in terms of engineering applications; these soils can be classified as highly plastic clays that are hard to compact. Natural mudstone-derived residual soils undergo severe disintegration underwater while remolded examples are similar but tend to exhibit more stable responses. Natural mudstone-derived residual soils behave in a structured way when subjected to shear and compression; these soil types possess superior natural shear resistance but their strength decreases significantly following saturation as well as in wetting and drying cycles. Data show that the microstructures of mudstone-derived residual soils are characterized by the presence of aggregations with fissures; although iron-bearing cementation between these aggregations is responsible for high soil strength, bonds can be damaged, or even destroyed, when samples are saturated or subjected to wetting and drying cycles leading to a reduction in shear strength. The results of this research provide clear parameters for related engineering applications and enhance our understanding of residual mudstone-derived soils.
显示更多 [+] 显示较少 [-]