盾构隧道下穿铁路路基施工过程对路基变形影响模拟分析

Simulation Analysis of the Influence of Shield Tunnel Underpass Railway Roadbed Construction Process on Roadbed Deformation

文中通过MIDAS有限元分析软件,模拟分析了贵州省贵阳轨道交通线路下穿火车站盾构隧道下穿铁路路基时不同影响因素对路基变形的影响规律。结果表明,铁路路基竖向沉降量理论值与模拟值基本一致,证实建立模型的准确性;黏土层下铁路路基比卵石层下的沉降量增加150%;隧道埋深为25m时,比隧道埋深11m时铁路路基最大沉降量降低了15.2%;隧道双向水平间距为25m时,比隧道双向水平间距8m时铁路路基沉降量降低了56.9%。下穿土层承载力越高、隧道埋深及双向水平间距越大时,铁路路基的沉降量控制效果越佳。

MIDAS finite element analysis software was used to simulate and analyze the influence of different factors on the embankment de-formation when the rail transit line underpasses the railway station in Guiyang,Guizhou province.The results show that the theoretical value of vertical settlement of railway subgrade is basically consistent with the simulated value,which confirms the accuracy of the model.The settle-ment of railway subgrade under clay layer is 150%higher than that under pebble layer.When the tunnel buried depth is 25 m,the maximum settlement of the railway roadbed is 15.2%lower than that when the tunnel buried depth is 11 m.When the tunnel two-way horizontal distance is 25 m,the settlement of railway roadbed is 56.9%lower than that when the tunnel two-way horizontal distance is 8 m.The higher the bear-ing capacity of the underlying soil layer,the greater the tunnel buried depth and the greater the two-way horizontal distance,the better the set-tlement control effect of the railway roadbed.