## 1 Introduction
Numerous scholars, including [PERSON] et al., have extensively researched the stability of double-entry layout coal pillars and the failure mechanisms of surrounding rock in roadways [21] and investigated the movement and fracture patterns of overlying strata above thick coal seams with hard roofs. [PERSON] et al. [22] obtained the variation laws of the principal stress and dilatancy characteristics in the plastic zone of retained entries, explaining the causes of the asymmetric deformation. [PERSON] et al. [23] calibrated field studies with the CMRI empirical formula to evaluate pillar performance under deeper overburdens. [PERSON] et al. [24] revealed the roof evolution laws under repeated mining: primary mining formed an \"F-shaped\" overlying rock structure, while secondary mining produced a \"T-shaped asymmetric/symmetric structure\". [PERSON] et al. [25] proposed a new pillar spalling model accounting for gradually reduced pillar sizes and the confining behavior of spalled coal fragments. [PERSON] et al. [26] analyzed the stress and displacement evolution mechanisms under varying coal pillar widths. [PERSON] et al. [27] identified mining-induced stress as the primary cause of roadway floor deformation and instability, proposing methods to improve stress conditions via optimized protective coal pillar widths for surrounding rock control. [PERSON] et al. [28] studied the double-entry layout beneath upper-seam pillars with interlayer spacing below 2 m. [PERSON] et al. [29] developed a differentiated control technology for double entries based on rib anchor cables and floor corner bolts. [PERSON] et al. [30] investigated the instability mechanisms and key influencing factors of deformation failures such as roof falls, rib convergence, and floor heave in return air roadways. [PERSON] et al. [31] investigated the failure characteristics of surrounding rock during goat entry excavation. [PERSON] et al. [32] identified large asymmetric deformation unevenly distributed along the roadway axial direction as a characteristic of surrounding rock deformation, proposing an asymmetric control strategy including rock homogenization, mass reinforcement, and coupled support in key zones. [PERSON] et al. [33] attributed intense non-uniform roadway subsidence and anchor cable fracture to expansion pressure and fragmentation/swelling deformation corresponding to rock failure within heterogeneous plastic zones. The above scholars have carried out extensive research on roadway support and surrounding rock control. Double-lane synchronous tunneling has great advantages in coal mine production, which can significantly improve resource recovery rate and mining efficiency. Integrating the actual conditions of the double-lane layout at the Jinjitan Coal Mine with previous research findings, in this paper, theoretical calculations, numerical simulations, and on-site monitoring are employed to optimize the surplus coal pillar design of the double-roadway layout working face. Based on the different stress characteristics during the excavation of the 16 m coal pillar double roadway, a differential support design is proposed for the two types of roadways. It solves the superimposed damage due to the rotation of the two-sided working face in the return air roadway. At the same time, it can ensure the stability of the surrounding rock. The design's rationality is confirmed through on-site monitoring, providing a reliable safeguard for the safe and efficient operation of the working face.