Sensitivity analysis of multi-factors on the mechanical properties of hydrate-bearing sediments at different axial strain

Abstract

The storage of hydrate-bearing sediments (HBS) in the seafloor environment is influenced by several factors. It is crucial to understand the effect of the interactions between the factors on the mechanical properties of HBS. This study examines the impact of effective confining pressure, pore pressure, saturation, fine content, and clay content on the mechanical properties of HBS by using an orthogonal test (L₂₅(5⁶)) with 5 factors and 5 levels. The variation patterns of HBS mechanical properties under different conditions were investigated. The subsequent analysis further studied the influence of the sensitivity of the factors at different axial strain stages on mechanical parameters and evaluated their significance through different analytical methods. The results show that the effective confining pressure has the greatest influence on the strength, while the influence of other factors such as pore pressure, hydrate saturation, and clay content changes as the shear process. Furthermore, the degree of influence factors on secant modulus E₅₀ is ranked in order of significance as hydrate saturation, clay content, effective confining pressure, fine content, and pore pressure in the order of significance. A positive correlation was found between effective confining pressure and strength, whereas hydrate saturation and clay content showed an inverse relationship with secant modulus E₅₀. This study highlights the complex interactions between influencing factors and HBS mechanical properties, offering valuable insights for further research and practical applications.