Proceedings of the
8th International Symposium on Geotechnical Safety and Risk (ISGSR)
14 – 16 December 2022, Newcastle, Australia
Editors: Jinsong Huang, D.V. Griffiths, Shui-Hua Jiang, Anna Giacomini, Richard Kelly
doi:10.3850/978-981-18-5182-7_05-013-cd
Regional Reliability Sensitivity Analysis Considering Spatial Variability of Soil
1School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, China
2Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education and Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China
ABSTRACT
The influence of spatial variability of soil on geotechnical engineering such as the ultimate bearing capacity of shallow foundation can be considered by reliability analysis based on random field theory. However, reliability analysis can only estimate the reliability index or failure probability of geo-structures, which cannot identify the important regions of random fields. Hence, a reliability sensitivity analysis method considering spatial variability of soil (called RSA-KL-FORM-x) is proposed in this study, which employs the Karhunen-Loève (KL) expansion method and the first-order reliability method (FORM) as the method of realizing random field and reliability analysis method, respectively. In the proposed RSA-KL-FORM-x, mean reliability sensitivity index (MRSI) and standard deviation reliability sensitivity index (SDRSI) are defined as functions of coordinates in random field domain, which means that the MRSI (or the SDRSI) with larger absolute values can be regarded as important regions. A shallow foundation with spatially various cohesion of soil is adopted to illustrate the process of the RSA-KL-FORM-x. The results show that the top part of the soil in contact with the shallow foundation is an important region to improve the reliability of the shallow foundation.
Keywords: Reliability analysis, Reliability sensitivity analysis, Random field, Shallow foundation.
