ORIGINAL RESEARCH article

Front. Earth Sci.

Sec. Geohazards and Georisks

Volume 13 - 2025 | doi: 10.3389/feart.2025.1574818

This article is part of the Research TopicNatural Disaster Prediction Based on Experimental and Numerical MethodsView all 14 articles

Mechanical and deformation behavior of sandy mudstone under triaxial unloading creep testing

Provisionally accepted
Liu  XueLiu Xue1*Ying  Zong XueYing Zong Xue1Zheng  Fang kunZheng Fang kun1Duan  Cheng shiDuan Cheng shi1Wang  Hai YangWang Hai Yang1Hao  YangHao Yang2
  • 1CCCC Fourth Harbor Engineering Institute Co., Ltd, Guangzhou, China
  • 2China University of Mining and Technology, Xuzhou, Jiangsu Province, China

The final, formatted version of the article will be published soon.

The deformation caused by excavation unloading has time effect, and its transient mechanical and rheological responses will change to some extent. Currently, most research on rheological behavior is based on loading mechanics. Still, the rheological behavior under the unloading stress path is not considered, which is often inconsistent with the actual mechanical process. The unloading rheological tests of argillaceous sandstone under constant axial pressure and gradual unloading confining stress paths are carried out in the Tingzikou Irrigation District, and the triaxial unloading rheological characteristics of rock are preliminarily studied. The test results show that the instantaneous deformation and creep deformation of sandy mudstone increase with the increase of deviational stress under the step-by-step unloading stress level, and with the gradual unloading of confining pressure, the more the unloading history goes through, the larger the creep rate, the larger the creep deformation, and the more obvious the unloading effect and rheological characteristics. Based on the experimental results, the unloading rheological behavior of sandy mudstone under this stress path is well described by H-K three-element model, and the parameters of the unloading rheological constitutive equation of sandy mudstone are obtained by parameter regression fitting.

Keywords: Sandy mudstone, rock mechanics, Unloading creep, Rheological model, Mechanical behavior

Received: 11 Feb 2025; Accepted: 27 May 2025.

Copyright: © 2025 Xue, Xue, kun, shi, Yang and Yang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Liu Xue, CCCC Fourth Harbor Engineering Institute Co., Ltd, Guangzhou, China

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