Calculation of Earth Pressure on Straight Ditch Buried Rigid Pipe

Based on the unified twin shear strength theory, a new earth pressure formula is deduced for the straight groove buried rigid pipes, with a straight slip plane soil pressure calculation model established. Compared with traditional earth pressure calculation method, the new formula which considers influence of intermediate principal stress on the pipeline earth pressure can obtain the result which is much closer to the actual pipeline stress situation. The results determined from the proposed formula with an engineering example show the influence law of slot width and the thickness of the overburden on tube top soil pressure. The conclusions have some guidance significance for optimization design of pipeline engineering.