Internal Force Calculation Analysis for Buried Corrugated Steel Pipes Considering Soil-Structure Interaction

The stress condition of the soil in the interaction system between soil and buried corrugated steel pipes is greatly different from that in elastic half-space homogeneous earth. There are various earth pressure concentrations due to the soil structure interaction between soil and the steel pipes. As a result, the actual vertical soil pressure on the pipe's crown is smaller compared to the weight of the soil prism above the pipes. The flexibility of the corrugated steel pipes is smaller than that of the reinforced concrete structure and the soil pressure will change as the flexibility of the pipes changes. Different flexibility parameters of the steel pipes are selected to analysis. Based on finite element analysis and existing theoretical theories, the modified method of the soil pressure around the steel pipes is proposed. Then, referring to the method of internal force calculation with consideration of displacement compatibility between the conduit and the soil around it, further modification is proposed according to the characteristics of corrugated steel pipes' stiffness. In the end, the comparisons between the finite element analysis results and the theoretical calculation are analyzed. The calculating method is proved reasonable.