3D stability analysis of unsupported rectangular excavation under pseudo-static seismic body force

ABSTRACT

In this paper, the seismic stability number of unsupported excavations in cohesive-frictional soil under the influence of pseudo-static seismic body forces is examined. Three-dimensional finite element limit analysis is employed to numerically solve the upper and lower bounded models of unsupported excavations. The results are represented by a dimensionless stability number which is a function of four dimensionless parameters including the excavation aspect ratio, the excavated depth ratio, the soil’s effective friction angle, and the coefficient of horizontal earthquake acceleration. For the first time in literature, the influences of a soil’s effective friction angle and the coefficient of horizontal earthquake acceleration on the mechanisms of excavation failures are examined and discussed. Also presented is a case study to demonstrate the use of the proposed seismic stability number in studying unsupported excavations in seismic risk areas.

KEYWORDS:

• Stability
• excavations
• pseudo-static
• seismic
• finite element limit analysis

Acknowledgments

This research was supported by National Research Council of Thailand (NRCT): NRCT5-RSA63001-05, the Ratchadapisek Sompoch Endowment Fund (2021), Chulalongkorn University (764002-ENV), and the Second century Fund (C2F), Chulalongkorn University. This research was also funded by Thailand Science research and Innovation Fund Chulalongkorn University (CU_FRB65_dis(28)_153_21_19). The first author acknowledges the Civil Engineering Centennial Scholarship of Chulalongkorn University for supporting her during the study.

CRediT author statement

Patteera Petchkaew: Investigation, Formal analysis, Visualization. Suraparb Keawsawasvong: Methodology, Validation, Supervision, Writing - Original Draft. Weeradetch Tanapalungkorn: Investigation, Visualization, Writing - Original Draft. Suched Likitlersuang: Conceptualization, Supervision, Writing - Review & Editing, Project administration, Funding acquisition.

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Ethical approval

This article does not contain any studies with human participants or animals performed by any of the authors. It also has not been published by another journal.

Data Availability Statement

Data that support the findings of this study are available within the article.

Additional information

Funding

This work was supported by the Ratchadapisek Sompoch Endowment Fund (2021), Chulalongkorn University [764002-ENV]; National Research Council of Thailand [NRCT5-RSA63001-05]; Thailand Science research and Innovation Fund Chulalongkorn University [CU_FRB65_dis(28)_153_21_19].