Impact of Pit Excavation Proximity on Tunnel Integrity

Wuhan University of Technology, Wuhan, China

Kuan Wang: wellington589125@gmail.com

Abstract

This study meticulously investigates the influential dynamics exerted by pit excavation on structures of adjacent underground tunnels, with a specialized focus on the resultant deformation effects attributed to the varying proximities separating the excavation sites from tunnel constructs. Employing rigorous model analyses conducted at designated intervals ranging from 8 meters to 24 meters, the research successfully elucidates a definitive and consistent pattern; it is observed that augmenting the distance between the pit and the tunnel significantly diminishes the extent of tunnel deformation experienced both in horizontal and vertical perspectives. This critical relationship unearthed by the study underlines the paramount importance of adopting meticulously calculated engineering design and the implementation of robust monitoring systems as fundamental measures in mitigating the associated risks prevalent within the expanse of urban underground construction endeavors. Noteworthy within these discoveries is the revelation that horizontal tunnel displacements, in comparison to their vertical counterparts, are markedly more pronounced in their reaction to alterations in the spatial gap that lies between the pit and the tunnel. This distinct sensitivity accentuated in the horizontal displacements signals the imperative for the formulation and application of customized mitigation strategies, specifically honed to address the asymmetrical nature of deformation induced by pit excavation activities in close quarters to tunnel infrastructures. Hence, these insights provide a valuable impetus for stakeholders in the field of construction engineering to incorporate such nuanced understandings into their projects, thereby enhancing the overall stability and safety of subterranean constructions within densely developed urban territories.