Existing shield tunnel longitudinal deformation analysis method under newly-built tunnel top crossing condition

A method for analyzing longitudinal deformation of an existing shield tunnel under the upward crossing condition of a newly-built tunnel comprises the steps that S1, the existing shield tunnel is simplified into an elastic continuous beam placed on a foundation in the longitudinal direction, and an equivalent continuous beam model of the existing shield tunnel is established; s2, applying the mutual coupling effect of the soil body and the tunnel to the equivalent continuous beam model, and solving the function relationship between the vertical displacement of the tunnel node and the vertical free displacement of the soil body; and S3, the soil body vertical free displacement of the stratified foundation soil under the excavation unloading action of the newly-built tunnel is obtained, and longitudinal displacement distribution of the existing shield tunnel is deduced and obtained. According to the method, the natural stratifying property of the soil body is considered, the corresponding foundation parameter s