## 1 Introduction
Many of these models extend the critical-state model [50], enabling a more comprehensive analysis of temperature effects on the short-term behavior of clays and rocks [51; 52; 53; 54; 55]. Research into the multi-field coupling of rocks began in the 1950s, initially driven by the need to understand reservoir-induced seismic activity. Early investigations revealed that the behavior of rocks under multi-field conditions could not be explained by examining individual physical fields in isolation. Instead, it became clear that these fields interact in complex ways, with changes in one field potentially triggering or intensifying effects in another. This realization marked a significant shift in the approach to studying rock mechanics under multi-field coupling conditions, emphasizing the need for a more comprehensive understanding. In the study of multi-field coupling, two primary methods have emerged: direct coupling and sequential coupling. Direct coupling involves solving for the interactions between multiple physical fields, such as temperature, fluid flow, mechanical stress, and chemical reactions, simultaneously. This method is computationally efficient for scenarios where real-time interactions are crucial, as it avoids the need for iterative recalculations between fields. However, due to the high computational demand and the complexity of real-world systems, direct coupling is often limited to simpler models or small-scale scenarios. In contrast, sequential coupling is the more commonly used approach in multi-field research. This method involves iteratively calculating the effects of each field one after the other, feeding the results of one calculation into the next until the system reaches convergence. Although this process is more time-consuming, it allows for greater flexibility and accuracy when dealing with complex systems where interactions between fields evolve gradually over time [56; 57; 58; 59]. Sequential coupling is particularly useful for studying the long-term behavior of rocks under prolonged exposure to combined physical forces, such as those found in underground mining operations or deep geological storage facilities. It enables researchers to model not just the immediate effects of multi-field interactions but also the cumulative impact of these forces on rock stability over time. The rock mass itself is comprised of intact rock blocks interspersed with fractures, and research into multi-field coupling primarily focuses on the evolution of damage within these fractured rock masses. [PERSON] et al. [60; 61] synthesize findings from international modeling teams on joint novaculite and granite research. Individual team contributions detail varying approaches: [PERSON] et al. [62] devised hybrid mathematical and analytical solutions for modeling THMC-coupled processes with fluid flow in fragmented rock; [PERSON] et al. [63] analyzed the congener significance of THMC interactions in fluid flow investigations on ruptured novaculite and granite; [PERSON] et al. [64] employed an elastoplastic cellular automaton (EPCA) approach to simulate THMC coupling within a single crack; and [PERSON] et al. [65] examined water-granite interactions, focusing on pressure-solution effects in flow through a single crack under confinement. Currently, the analysis of fracture evolution, deformation mechanisms, mechanical constitutive modeling, and the construction of multi-field coupling models are among the most challenging and active areas of research in rock mechanics. Scholars worldwide have recognized the importance of this field, and it has garnered significant attention. For example, the DECOVALEX project [66] (DEmonstration of COupled models and their VALidation against Experiments), an international collaborative effort that began in 1992, has conducted extensive multi-scale experiments on the multi-field coupling of rocks. This project developed and validated THM cross-coupling models, which represented the cutting-edge research at the time.