新八达岭隧道下穿青龙桥车站变形控制技术

Control Technology for Qinglongqiao Station Deformation Triggered by Newly-built Badaling Tunnel

依托京张高铁新八达岭隧道下穿既有京张铁路青龙桥车站工程,为控制下穿过程中青龙桥车站的沉降变形,采用Midas GTS NX数值模拟软件,模拟隧道下穿车站的施工全过程,得到既有车站路基变形的沉降曲线。研究发现路基最大沉降发生在新建隧道拱顶上方,路基累计最大沉降16.017 mm,建议在隧道施工过程中通过控制循环进尺和施工速度来控制路基的沉降量,并及时补充道砟,恢复轨道沉降变形,从而控制轨道的沉降。提出洞内φ159 mm超前大管棚注浆加固、洞外地表垂直袖阀管注浆加固和3-5-3扣轨加固的变形控制技术,为下穿工程控制沉降变形提供经验借鉴。

Based on the project of Newly-built Badaling Tunnel of Beijing-Zhangjiakou High-speed Railway tunneling under the Qinglongqiao Station of the existing Beijing-Zhangjiakou Railway,the whole construction process of the new tunnel is simulated using Midas GTS NX numerical simulation software so as to control the ground settlement,and the deformation curve of the existing station subgrade is obtained.It is found that the maximum settlement of the subgrade occurs above the tunnel crown and the cumulative maximum settlement is 16.017 mm.The results suggest that advance footage and speed should be controlled in a reasonable range and ballast should be added timely to restore track settlement.Then,such deformation control technologies are put forward as advanced long pipe shed of■159 mm,surface grouting reinforcement with vertical sleeve valve tube and 3-5-3 buckled rail reinforcement,which provide references for ground settlement control of underpass projects.