## 1 Introduction  
To solve the problems associated with transportation, ventilation, and gases, many underground coal mines in China still employ a two-entry longwall panel system [1, 2]. The roadway in this system is subjected to two mining influences and strong ground pressure behaviors; consequently, roadway maintenance is more difficult [3, 4]. Therefore, considerable research has been devoted toward the failure characteristics and control technology of roadways in two-entry longwall panel systems.  
In the field of roadway surrounding rock control, many scholars have proposed roadway support theories and technologies. For instance, [PERSON] et al. proposed and verified a rock mass rating (RMR)-based bolt design considering the underground coal mines in India [5]. [PERSON] et al. confirmed that high-constant-resistance anchor cables can effectively control roadway deformation [6]. [PERSON] et al. proposed a rock bolt system for the ground reinforcement of longwall roadways within soft rock masses and successfully applied this approach in the field [7]. [PERSON] et al. proposed a novel \"bolt-cable-mesh-shotcrete + shell\" combined support for a ventilation roadway [8]. [PERSON] et al. confirmed the effectiveness of combined yielding steel arch with rock bolt support systems under different mining conditions [9]. [PERSON] et al. employed artificial neural networks (ANNs) to predict the stability conditions of longwall roadways based on roof displacements [10]. Toobtain a qualified support design, it is necessary to first analyze the failure of the roadway surrounding rock. After realizing the support design, its rationality must be verified through field applications.  
Failures in the surrounding rock of roadways are primarily caused by the distribution of the plastic zone in the rock. Roadways are affected by mining, which, in turn, results in stress concentration in the surrounding rock and plastic failure of the rock masses [11, 12, 13]. Thus, many scholars have conducted extensive research on the plastic zone and stress distribution law of roadways; various formulas for calculating the plastic zone in roadway surrounding rocks have also been proposed [14,15]. Such research has enriched the theoretical system of surrounding rock control. Furthermore, scholars have used different experimental and numerical methods to collate a large number of field application cases [16, 17, 18, 19, 20]; this is also expected to serve as a reference for future research in this field. Researchers have reported that the principal stress has a significant influence on the stability of roadway surrounding rocks [21, 22, 23, 24]. Therefore, when studying the stability of roadway surrounding rocks, it is necessary to analyze the influence of the principal stress on the distribution of the plastic zone.  
Many research methods have been employed in these studies, which provide a strong basis for the failure characteristics and control technology of roadways in two-entry long-wall panel systems. However, for the same problem, the research conclusions when using different research methods are not entirely identical. To address this discrepancy, in this study, three methods were used: a calculation formula for the roadway plastic zone, fast Lagrangian analysis of continua 3D (FLAC\({}^{\text{3D}}\)) numerical modeling, and field observation employing broken rock zone detection. This work aimed to obtain comprehensive and thorough research results, which are expected to serve as a reference for the control of roadway surrounding rocks under similar geological conditions.