桩基对既有高铁隧道群变形影响的数值分析

Numerical Analysis of Influence of Pile Foundation on Deformation of Existing High-speed Railway Tunnel Group

某拟建地铁停车场运用库上跨高铁隧道群,基础采用桩基础形式,共24根,位于两高铁隧道之间。桩基与隧道的最小净距为3 m,同时近距离跨越三条高铁隧道群。由于高铁隧道顶土体松散、桩顶荷载大、桩距隧道近等特点,桩基施工及桩基荷载可能对隧道产生影响。建立了三维有限元数值模型,模拟了桩基础承担的荷载通过桩土作用,对既有隧道结构应力、变形产生的影响,同时分析了群桩基础叠加效应对既有隧道的影响。

As the warehouse of a proposed subway parking lot above a group of high-speed railway tunnels adopts the form of pile foundation a total of 24,which are located between the two high-speed railway tunnels,the minimum clear distance between the pile foundation and the tunnel is 3 m,and it covers three high-speed railways tunnel groups in close distance,which has made it to be the first in the country.Due to the loose soil on the top of the high-speed railway tunnel,the large load on the pile top,and the short distance between pile and tunnel,both the construction of the pile foundation and the pile foundation load may affect the tunnel.A three-dimensional finite element numerical model has been established to simulate the effect of the pile foundation load on the stress and deformation of the existing tunnel structure through the pile-soil action,and the influence of the pile group foundation superimposition effect on the existing tunnel has also been considered.