| Kangjiagou is located in the northern Shaanxi tectonic belt,the stratum soil is mainly loess,the region of gullies developed,containing a small amount of silt is bad geology,the regional geological conditions are poor.Because of the consolidation and settlement of the soil in the filling area,the safety and stability of the pipe gallery will be affected to a certain extent when the pipe gallery is used in the northwest city with high filling loess area.Based on our common types of eccentric vertical plate pipe gallery and neutral plate pipe gallery,both of them have their advantages and disadvantages in design and construction.Therefore,based on Kangjiagou excavated and filled area as the background,this study adopts ABAQUS software to simulate the orthogonal crossing of comprehensive pipe gallery through the combined area of excavated and filled with previous data.In order to explore the characteristics of stress and strain of two kinds of pipe corridors under the settlement action of filling area,and to provide theoretical basis for the selection and design of pipe corridors in engineering,the following studies were carried out:1.The vertical displacement of the stratum and the ground surface is a quadratic parabola with an upward opening in the horizontal z direction when the consolidation settlement occurs in the fill area.The displacement of x,Y and Z direction will increase with the increase of settlement.The vertical displacement of the pipe gallery is reverse"s"shape,the roof and floor are divided into "v"shape and inverted"v"shape.There is a certain void area near the junction area of the top of the pipe gallery and a slight void area at the bottom of the pipe gallery.2.The stress of the partial plate and neutral plate pipe gallery is earth pressure in the section of excavation and fill,and the vertical stress of the pipe gallery located in the combined section changes sharply due to the settlement of fill.The vertical stress of the bottom plate is mainly concentrated in the section where the excavation and filling are combined.The top and bottom plates of the Z direction horizontal stress in the Pipe Gallery have the opposite mechanical properties,the curves are symmetrical,and the stress in the filling area is very small.The stress in x direction is smaller than that in z direction and vertical direction,and the stress curve is similar to horizontal straight line.The shear value of the pipe gallery changes suddenly at the two boundaries of the joint zone of excavation and filling,which should be reinforced.3.Because of the settlement of the fill area,the pipe gallery has some deflection deformation,and the strain of the pipe gallery roof and the pipe gallery floor in the cut-fill area is vertical tensile strain.In Z direction,the roof of the pipe gallery is pulled in the excavation area and pressed in the joint area,but the bottom plate is opposite.In x direction,the strain is mainly compressive strain at the top of the excavation section and the bottom of the joint zone.4.Through the comparison between the neutral plate pipe gallery and the eccentric plate pipe gallery,it can be seen that the displacement and stress characteristics of the two kinds of pipe gallery are similar under the condition of the settlement of the filled area.The displacement,stress and strain of the eccentric plate gallery are larger than those of the neutral plate gallery,and it is easy to be distorted.5.simplify mechanics research,elaborate three kinds of failure mode,and put forward three kinds of early warning basis based on failure mode,in order to ensure the safety and stability of the pipe gallery,we should increase the strength of reinforced concrete for the pipe gallery in the section of combined excavation and filling,the measures of setting up joint and flexible joint in sections. |
