涉铁桩基施工对地铁隧道影响分析

Analysis of Influence of Railway-related Pile Foundation Construction on Subway Tunnel

邻铁桩基施工过程中的土体扰动极易对既有地铁隧道产生不利影响,隧道主体结构变形是桩基施工过程中主要监测对象。依托宁马(南京至马鞍山)高速公路油坊桥互通工程,基于隧道结构监控数据,分析桩基施工过程中隧道结构水平、沉降及收敛变形特征,研究桩基施工对隧道结构影响。结果表明:桩基施工距隧道结构越远,影响越小,间距超过14m,扰动影响可以忽略;邻铁桩基采用全套管灌注桩施工会对隧道结构产生侧向挤压作用,产生较大的水平及收敛变形;施工过程应重点监测隧道结构渗水及管片错台病害,并及时进行病害治理,研究可为同类工程施工提供参考。

The soil disturbance during the construction of adjacent railway pile foundation is easily to exert adverse effects on the existing subway tunnel,and the deformation of the main structure of the tunnel is the main monitoring object during the construction of pile foundation.Relying on the interchange project of Youfang Bridge over Ningma(Nanjing-Ma'anshan)expressway,based on the monitoring data of tunnel structure,the characteristics of tunnel structure level,settlement and convergence deformation in the process of pile foundation construction are analyzed,and the influence of pile foundation construction on tunnel structure is studied.The results show that:the farther the pile foundation construction is away from the tunnel structure,the smaller the impact is,the distance is more than 14m,and the disturbance effect can be ignored;the full casing cast-in-place pile construction of adjacent railway pile foundation will produce lateral compression effect on the tunnel structure,resulting in large horizontal and convergence deformation;the tunnel structure seepage and segment dislocation disease should be monitored emphatically in the construction process,and the disease treatment should be carried out in time,so as to provide reference for the research on the construction of similar projects.