Study On The Force And Deformation Of Underground Comprehensive Pipe Gallery Under Earthquake Action

The underground comprehensive pipe gallery is simply to bury multiple underground pipelines in an underground tunnel.China is an earthquake-prone country.The destruction of underground structures under the action of earthquake will seriously affect People's Daily life and safety.Therefore,the research on the stress and deformation under the seismic action of the underground comprehensive pipe gallery can provide some experience and reference for the future design.The background of this paper is based on an underground pipe gallery project in China,in this paper,the characteristics of field?strata?structure were analyzed,based on the reaction displacement method,this paper calculate the dynamic spring stiffness,soil displacement,soil friction,soil shear stress,etc.of the structure under the action of multiple earthquakes and rare earthquakes.Then use MADAS-GEN finite element software to calculate the internal force distribution characteristics and deformation law of the three structural sections of the tube gallery under the action of multiple earthquakes and rare earthquakes.The specific research contents and results are as follows:(1)Under the action of multiple earthquakes,along the buried depth of the structure,at the same elevation,the axial force of the column is about 2.49 ~ 5.45 times more than the axial force of the lateral wall,so the column is the main pressure component under the earthquake.Shear and bending moment values also gradually increase along the depth direction of the structure,and the side wall bears greater shear and bending moment than the column,and the shear force and bending moment at the junction between the side wall and the standard layer are slightly larger than those of the side wall and the ground floor.At the same elevation,the shear and bending moment values of the side wall are 2.51 to 3.05 and 1.36 to 3.09 times larger than that of the column,respectively.Under the effect of rare earthquakes,the changes in internal forces in three structural sections are similar to those under multiple earthquakes.At the same elevation,the axial force of the column is approximately 3.2 to 4.6 times the axial force of the side wall.the shear and bending moments of the side walls are 1.13 to 2.01 times and 1.16 to 2.33 times that of the column,respectively.(2)three cross sections show a similar structure deformation trend in multiple earthquakes and rare earthquakes:the displacement at the top layer is the largest,and the displacement along the buried direction is gradually smaller.Under the action of multiple earthquakes,the relative displacement of the roof of the five storehouse structure is 2.8698 mm,under the rare earthquakes,the relative displacement of the roof of the five storehouse structure is 8.184 mm.(3)Through the research and conclusion of this paper,we should pay attention to the column in seismic design,which is the main pressure-retaining component.In the side wall and the standard layer,the connection between the bottom layer are prone to bending and shear be damaged,we can enhance its seismic performance by increasing its concrete strength grade or increasing the ratio of reinforcement in project design.(4)The deformation at the top of the structure is relatively largest.In this type of position,some elastic restraints can be setted along the longitudinal direction of the pipe gallery at intervals,so as to prevent the structure from being destroyed due to excessive displacement.(5)The inadequacies of this paper are that it only established the two-dimensional model.If a three-dimensional reactive displacement method analysis model can be established,the parameters of structural unit,boundary,and damping are set,like the two-dimensional model,the results will be more accurate.