Abstract:To further understand the effect of deep foundation pit excavation on surrounding pipelines and determine the pipeline displacement track model, with the background of a deep foundation pit project of Nanjing, the analysis is made on the actual monitoring data of pipeline displacement. The design, construction and monitoring schemes of the foundation pit project are introduced; on this basis, according to the construction process, this paper analyzes the variation rules of vertical settlement and horizontal displacement of 4 surrounding pipelines and explores the relationship between them to reveal pipeline displacement track. By the analysis, it is concluded that the vertical settlement happened prior to the horizontal displacement in time domain, along with the development of foundation pit construction, vertical settlement and horizontal displacement developed synchronously; after the completion of the second support construction for foundation pit, the vertical settlement exhibits plateaus and the horizontal displacement reduced; after the construction of the basement floor, both the horizontal settlement and vertical displacement tend to be stable. The track of the pipeline displacement track vertically closer to the foundation pit side wall is a cubic polynomial curve and the pipeline displacement track far from the foundation pit side wall moves straightly toward the foot of the pit.