Abstract: Current research on deep-sea gas-bearing energy soils primarily focuses on soils with small air bubbles in a relatively stable state. Sinusoidal waves are commonly used in experiments to simulate seismic waves. Therefore, the authors propose a method to control bubble size and content, converting the acceleration time-history of seismic waves into stress time-history curves to replace sinusoidal waves. Dynamic triaxial tests are conducted to investigate the dynamic characteristics of various components of gas- bearing soils under seismic condition. The experiments show that under seismic loading, the failure modes of gas-bearing soils vary with confining pressure, including compression and tension failures. Different clay contents exhibit both strain failure and liquefaction failure. Higher clay content results in decreased stiffness and shear strength, but increased plastic deformation capacity of gas-bearing soils. Effective confining pressure significantly impacts gas-bearing soils. As saturation decreases, dynamic strength of soils diminishes, and the influence of effective confining pressure becomes more pronounced.

Key words: deep-sea gas-bearing energy soil, seismic loading, dynamic triaxial test, failure mode, dynamic characteristics