Mechanical Properties and Damming Behaviors of Gravelly Solidified Soil for Earth-Rock Dam Core Wall

To decrease the arch effect of core wall effectively has become an important requirement for high earth-rock dams. To address this issue, a soil solidifier was used to improve the properties of gravelly soil. This study investigated the durability and mechanical performances of gravelly soils mixed with different proportions of solidifier through the permeability, freeze-thaw, and triaxial compression tests. Furthermore, the microstructure of gravelly solidified soil was explored, and the mechanism for the performance improvement was explained. Finally, the influence of mixing the solidifier on dam stress, deformation and the decrease of arch effect was analyzed using the finite element method. The results indicate that a large number of long needle-like hydrates and crystalline interlocking structures are present in the gravelly solidified soil. Therefore, the impermeability, frost resistance, toughness and shear strength of the gravelly solidified soil are significantly higher than those of the normal gravelly soil. In addition, the settlement and the arch effect are decreased dramatically with mixing the solidifier. Thus, this study provides an alternative to high core wall materials and a new approach to improve the arch effect of 300-meter-height level core wall earth-rock dams.