Abstract: In the design of buried steel pipes, the influences of surrounding soil and trench on the steel pipes need to be taken into consideration, which are researched inadequately. The sensitivities of such parameters inclusive of the deformation modulus E₁ of backfill, the deformation modulus E₂ of sand bedding, the bedding angle θ, the trench bottom width B, and the inclination angle α of trench sidewalls to test indices (maximum vertical deformation of pipe, circumferential bending stresses of pipe top, springline, and bottom) were examined via an orthogonal test method. Results suggest that E₁, E₂, and α are highly sensitive to the test indices, while B bears low sensitivity to the test indices, and θ has the lowest sensitivity. The high soil deformation modulus and narrow excavation trench are beneficial to the structure of buried steel pipes, while the inclination angle of trench sidewalls has a complex influence on pipes and needs to be analyzed in line with specific situation. The research findings provide references for the parameter design of buried steel pipes.

Key words: buried steel pipes, sensitivity analysis for parameters, orthogonal test method, finite element method, structure design