Geomechanics and Engineering

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Reliability analysis of strip footing under rainfall using KL-FORM

  • Fei, Suozhu (School of Resources and Environmental Engineering, Hefei University of Technology) ;
  • Tan, Xiaohui (School of Resources and Environmental Engineering, Hefei University of Technology) ;
  • Gong, Wenping (Faculty of Engineering, China University of Geosciences) ;
  • Dong, Xiaole (School of Resources and Environmental Engineering, Hefei University of Technology) ;
  • Zha, Fusheng (School of Resources and Environmental Engineering, Hefei University of Technology) ;
  • Xu, Long (School of Resources and Environmental Engineering, Hefei University of Technology)
  • Received : 2020.07.15
  • Accepted : 2021.01.08
  • Published : 2021.01.25
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Abstract

Spatial variability is an inherent uncertainty of soil properties. Current reliability analyses generally incorporate random field theory and Monte Carlo simulation (MCS) when dealing with spatial variability, in which the computational efficiency is a significant challenge. This paper proposes a KL-FORM algorithm to improve the computational efficiency. In the proposed KL-FORM, Karhunen-Loeve (KL) expansion is used for discretizing random fields, and first-order reliability method (FORM) is employed for reliability analysis. The KL expansion and FORM can be used in conjunction, through adopting independent standard normal variables in the discretization of KL expansion as the basic variables in the FORM. To illustrate the effectiveness of this KL-FORM, it is applied to a case study of a strip footing in spatially variable unsaturated soil under rainfall, in which the bearing capacity of the footing is computed by numerical simulation. This case study shows that the KL-FORM is accurate and efficient. The parametric analyses suggest that ignoring the spatial variability of the soil may lead to an underestimation of the reliability index of the footing.

Keywords

Acknowledgement

This work was supported by the National Natural Science Foundation, China (41972278; 41572282). We would like to thank Uni-edit (www.uni-edit.net) for editing and proofreading this manuscript.

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