Research on the displacement of a comprehensive utility tunnel in silty soil based on finite element method
GUO Peipei
JI Hongyu
WANG Shengli
TU Xiongwei
HU Peng
CHI Lianyang
Abstract：To study the impact of groundwater level changes on the displacement of a comprehensive utility tunnel in loess areas,a numerical model of the buried comprehensive utility tunnel is constructed using the finite element software PLAXIS 3D.To verify the reliability of the numerical model,a scaled model of the buried comprehensive utility tunnel is established according to similarity theory,with a scale ratio of 1:20.By varying the groundwater level height,river channel water level,and burial depth,the changes in the displacement of the comprehensive utility tunnel are simulated and analyzed.The results indicate:1)The scaled model tests can validate the reasonableness of the seepage parameters set in the numerical model,which can be used to analyze the impact of different groundwater levels on the displacement of the comprehensive utility tunnel.2)As the vertical drop of the groundwater level increases,the further away the road surface is from the comprehensive utility tunnel in the vertical direction,the greater the settlement of the road surface;when the vertical drop of the groundwater level is 5-7 m,the settlement difference between the road surface above the comprehensive utility tunnel and that of the adjacent non-tunnel areas gradually decreases;when the vertical drop of the groundwater level is 8 m,the settlement of the road surface above the comprehensive utility tunnel is significantly higher than that of the adjacent non-tunnel areas.As the vertical rise of the groundwater level increases,the further away the road surface is from the comprehensive utility tunnel in the horizontal direction,the smaller the displacement of the road surface,and the greater the maximum displacement difference between the road surfaces in the comprehensive utility tunnel area and the adjacent non-tunnel areas;the maximum displacement difference of the plane foundation at the bottom of the comprehensive utility tunnel increases,which is significantly greater than the maximum displacement difference of the road surface at the same groundwater level height.3)The vertical and lateral displacements of the comprehensive utility tunnel exhibit periodic changes with variations in the river channel water level;during the dry season,the river channel water level decreases,which leads to increased settlement and lateral displacement of the comprehensive utility tunnel,while during the wet season,the river channel water level rises,causing the comprehensive utility tunnel to return to its original position,with the displacement near the river channel and road surface being significantly affected by the fluctuations in the river channel water level.4)As the groundwater level decreases,the shallower the burial depth of the comprehensive utility tunnel,the greater the settlement;the displacement of shallow-buried tunnels is significantly affected by changes in the groundwater level.In practical engineering applications of comprehensive utility tunnels,shallow burial is not advisable in high water level areas.
Keywords：comprehensive utility tunnelfinite element analysisground water levelriverway leveldisplacement
Publication Date：2025-07-30
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：9( 44-51,107 )