Analysis of stress and deformation of a positive buried pipe using the improved Spangler model

In the Spangler model, the vertical earth pressure is assumed to be uniformly distributed, but it is not. The aim of this study is to improve the accuracy of the stress and deformation calculation for a positive buried pipe by using the new formulae derived from an improved Spangler model. Based on the Spangler model, this study derives the general calculation formulae for the section moment of a buried pipe when the vertical earth pressure is arbitrarily distributed. Furthermore, this study proposes a new model by improving the Spangler model, in which the vertical earth pressure is assumed to be parabolically distributed. Then, the new deformation formulae are derived. At the end of this article, the results of the new formulae are validated through a comparison with the simulated results obtained by FLAC3D software. It is concluded that the new model can simulate the behavior of buried pipes better than the Spangler model.