This paper explores the influence of dynamic behaviour under earthquake loading and soil heterogeneity on the bearing capacity of the strip footing over a horizontal ground of cohesionless soil. A finite element lower bound limit analysis formulation with second-order conic optimisation is used for the analysis. Dynamic behaviour of seismic waves is incorporated using a modified pseudo-dynamic approach. Spatial distribution of soil is generated by discretising the random field of internal friction angle using Karhunen-Loéve (KL) expansion method. The stochastic response is determined using Monte Carlo Simulation technique. Design charts for mean seismic bearing capacity factor and probability of failure of the footing are provided for practical cases of soil heterogeneity and seismic acceleration. It is found that the consideration of high factor of safety, such as 3, also does not ensure that the structure is safe against failure. The dynamic effect of seismic waves is studied by comparing the plastic yielding of soil at various intervals of time per period of lateral shaking (t/T). It is observed that the failure pattern changes with respect to t/T interval and attains maximum yielding at the t/T ratio corresponding to the least magnitude of seismic bearing capacity factor.

本文探讨了地震荷载和土壤异质性下的动态行为对无粘性土水平地面上条形基础承载力的影响。分析使用具有二阶圆锥优化的有限元下限分析公式。地震波的动态行为是采用一种改进的拟动力方法来实现的。土壤的空间分布是通过使用Karhunen-Loéve（KL）扩展方法离散内摩擦角的随机场而生成的。随机响应是使用蒙特卡洛模拟技术确定的。针对土壤异质性和地震加速度的实际情况，提供了平均地震承载力系数和立足失败概率的设计图。已经发现，考虑高安全系数，例如3，也不能确保该结构是安全的以防损坏。通过比较每个横向振动周期在不同时间间隔内土壤的塑性屈服来研究地震波的动力效应（t / T）。可以看出，破坏模式随t / T间隔而变化，并在对应于最小地震承载力因子的t / T比处获得最大屈服。