隧道下穿长水机场敏感区域施工技术与稳定性研究OA

To address the challenges of structural safety assurance and settlement control during tunnel construction crossing the sensitive airport areas,this study examined the Changshui Airport tunnel project.By integrating 3D fi-nite element simulation with on-site monitoring,the impact of construction techniques and protective measures on stability was investigated.The research findings indicate that the surface settlement exhibits a"double-L"distribu-tion pattern with the tunnel advances,and the construction area affects a range of 20.0 meters;Characteristics of ground settlement perpendicular to the tunnel direction was in a"V"shape by bench method,and the tunnel center-line and both flanks were critical control zones;The three-step bench method with a 4.0 m spacing emerged as the optimal solution.When bench spacing increased from 4.0 m to 8.0 m,the surface settlement increased by 25.86％.The three-step bench method was superior to the conventional bench method in controlling surface subsidence and the number of bench steps influenced settlement.Unreinforced or single grouting/bolting reinforcement failed to meet settlement requirements.The combined grouting+bolting reinforcement reduced settlement by 55.81％.The effect of arch crown settlement was better than that of arch bottom heave.The control effectiveness ranking is:combined reinforcement＞grouting reinforcement＞bolting reinforcement.This research provides theoretical foundations and engineering references for controlling settlement and structural safety in sensitive areas such as tunnels crossing air-ports,and enhancing construction stability as well.