Undrained stability of braced excavations in clay considering the nonstationary random field of undrained shear strength

Weeradetch Tanapalungkorn; Wittawat Yodsomjai; Suraparb Keawsawasvong; Thanh Son Nguyen; Weeraya Chim-Oye; Pornkasem Jongpradist; Suched Likitlersuang

doi:10.1038/s41598-023-40608-5

Undrained stability of braced excavations in clay considering the nonstationary random field of undrained shear strength

Sci Rep. 2023 Aug 16;13(1):13358. doi: 10.1038/s41598-023-40608-5.

Authors

Weeradetch Tanapalungkorn¹, Wittawat Yodsomjai², Suraparb Keawsawasvong³, Thanh Son Nguyen¹, Weeraya Chim-Oye⁴, Pornkasem Jongpradist², Suched Likitlersuang⁵

Affiliations

¹ Centre of Excellence in Geotechnical and Geoenvironmental Engineering, Department of Civil Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, 10330, Thailand.
² Construction Innovations and Future Infrastructures Research Center, Department of Civil Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangkok, 10140, Thailand.
³ Research Unit in Sciences and Innovative Technologies for Civil Engineering Infrastructures, Department of Civil Engineering, Faculty of Engineering, Thammasat School of Engineering, Thammasat University, Pathumthani, Thailand. ksurapar@engr.tu.ac.th.
⁴ Department of Civil Engineering, Faculty of Engineering, Thammasat School of Engineering, Thammasat University, Pathumthani, Thailand.
⁵ Centre of Excellence in Geotechnical and Geoenvironmental Engineering, Department of Civil Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, 10330, Thailand. fceslk@eng.chula.ac.th.

Abstract

The basal heave stability of supported excavations is an essential problem in geotechnical engineering. This paper considers the probabilistic analysis of basal heave stability of supported excavations with spatially random soils by employing the random adaptive finite element limit analysis and Monte Carlo simulations to simulate all possible outcomes under parametric uncertainty. The effect of soil strength variability is investigated for various parameters, including the width and depth of the excavation ratio, strength gradient factor, and vertical correlation length. Probabilistic basal stability results have also been employed to determine the probability of design failure for a practical range of deterministic factors of safety. Considering probabilistic failure analysis, the more complete failure patterns caused by the various vertical correlation length would decrease the probability of design failure. There are different tendencies between the probability of design failure at the same safety factor with various vertical correlation lengths. These results can be of great interest to engineering practitioners in the design process of excavation problems.