Gassy soils are widely distributed in river deltas, coastal and marine sediments. The discrete bubbles, commonly formed in gassy soil, are sensitive to temperature and pressure variations and contribute to the changes in soil properties, e.g. compressibility and permeability. This paper develops a precise model, considering the effects of gas bubble thermal expansion, saturation degree (S) and distance from the soil to water surface (H), to investigate the behaviour of gassy marine soils. The expansion and compression of bubbles are introduced into a new derived non-isothermal seepage equation. With the aid of Taylor series expansion and integral transform, such problems are solved by a recently developed precise integration method (PIM), which proves to be remarkably efficient and several orders more precise for quasi-static problem of porous media than conventional numerical approaches. Typical examples are performed to examine the effects of bubble expansion, S and H on the gassy soils behaviour. The bubble thermal expansion induces remarkable excess pore pressure and increase the displacement amplitude, which is enhanced by larger H or lower S. Under mechanical loading, instantaneous displacement decreases with S and H, and a S-H critical line is proposed to assess this effect, which is conducive to engineering design.

含气土壤广泛分布在河流三角洲、沿海和海洋沉积物中。离散气泡通常在含气土壤中形成，对温度和压力变化敏感，并有助于土壤特性的变化，例如可压缩性和渗透性。本文开发了一个精确模型，考虑了气泡热膨胀、饱和度 ( S ) 和土壤到水面距离 ( H)，研究含气海洋土壤的行为。气泡的膨胀和压缩被引入到一个新的非等温渗流方程中。在泰勒级数展开和积分变换的帮助下，最近开发的精确积分方法 (PIM) 解决了这些问题，该方法被证明对于多孔介质的准静态问题非常有效，并且比传统数值方法更精确几个数量级。执行典型示例以检查气泡膨胀、S和H对含气土壤行为的影响。气泡的热膨胀引起显着的超孔隙压力并增加位移幅度，这通过较大的H或较低的S增强. 在机械载荷作用下，瞬时位移随S和H减小，提出了S - H临界线来评估这种影响，有利于工程设计。