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ORIGINAL RESEARCH article

Front. Earth Sci.

Sec. Geohazards and Georisks

Volume 13 - 2025 | doi: 10.3389/feart.2025.1655762

This article is part of the Research TopicNatural Disaster Prediction Based on Experimental and Numerical MethodsView all 25 articles

Phase field modelling of the hydro-mechanical coupling failure mechanisms of fissured rock masses

Provisionally accepted
Miaomiao  KouMiaomiao Kou1,2Chenxi  LiChenxi Li2Yan  WangYan Wang1,2*Fei  LiuFei Liu1,2
  • 1State Key Laboratory of Water Resource Protection and Utilization in Coal Mining, Beijing, China
  • 2Qingdao University of Technology, Qingdao, China

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

Exploring the mechanical response and damage mechanism of fractured rocks under hydromechanical coupling is a key approach to address the safety and stability problems of rock engineering under hydro-mechanical coupling conditions. Based on Biot theory and pore elasticity theory, a numerical simulation method of hydro-mechanical coupled phase field is developed, and a staggered time integration scheme is proposed to obtain stable solutions of fluid pressure and solid deformation, in which the obtained control equations adopt the volume strain separation and partial strain separation of the elasticity theory of fully saturated porous media. Two different numerical examples of fluid permeability tests and hydraulic fracturing with natural fracture interaction are used for validation. During the comparison of the numerical model with the analytical solution, the numerical results and the previous data are in better agreement, which verifies the validity and correctness of the model method. In addition, in order to investigate the unloading damage mechanism in the actual engineering excavation process, a hydro-mechanical coupled unloading damage model was established by combining numerical examples of borehole injection tests to simulate the whole process of fracture rock propagation damage under the dual conditions of hydro-mechanical coupling and surrounding pressure unloading. The study shows that fluid infiltration and hydraulic fracture crack expansion are mainly controlled by tensioning action, while mixed tensile-shear crack expansion and connection dominate the final damage mode during coupled hydro-mechanical unloading damage.

Keywords: fissure rock masses, hydro-mechanical coupling process, unloading failure mechanisms, phase-field approach, Numerical Simulations

Received: 28 Jun 2025; Accepted: 30 Jul 2025.

Copyright: © 2025 Kou, Li, Wang and Liu. 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: Yan Wang, State Key Laboratory of Water Resource Protection and Utilization in Coal Mining, Beijing, China

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