This study investigates the ultimate bearing capacity and typical failure mechanisms of a rough strip footing constructed above an irregular cavity using the upper bound finite element limit analysis (UBFELA) method. A novel method based on the inverse discrete Fourier transform (IDFT) theory is employed to generate and quantitatively describe the irregular shape of natural cavities. Parametric studies are performed to study the influence of several variables, including the ratio of the cavity size to the strip footing width (D/B), the ratio of the cover depth to the footing width (H/B), the internal friction angle (φ), the direction angle of the long axis of the cavity (θ) and the shape descriptors of the cavity (D₂, D₃, and D₈). Numerical results are presented in the form of dimensionless charts for the bearing capacity numbers (P_u/c). The obtained failure modes present significant asymmetry and a critical region is found to be greatly affected by the size of the cavity (D/B), the cavity depth (H/B) and the internal friction angle (φ).

这项研究使用上限有限元极限分析（UBFELA）方法研究了在不规则空腔上方构造的粗糙带状基础的极限承载力和典型破坏机理。一种基于离散傅里叶逆变换（IDFT）理论的新颖方法被用来生成和定量描述自然空腔的不规则形状。进行参数研究来研究几个变量的影响，包括型腔尺寸与带钢立足宽度的比率（D / B），覆盖层深度与立足宽度的比率（H / B），内摩擦角（φ），腔长轴的方向角（θ）和腔体的形状描述符（D ₂，D ₃和D ₈）。数值结果以无因次图的形式显示了承载力数值（P _u / c）。所获得的失效模式表现出明显的不对称性，并且发现一个关键区域受到空腔尺寸（D / B），空腔深度（H / B）和内摩擦角（φ）的极大影响。