Analysis Method for a Pipe Subjected to Surface Load

The Marston soil-pressure mode is used to calculate the top pressure of the pipe subjected to the surface load. In the calculation, the load caused by soil weight is deal with as the pipe buried depth. The Spangler-Iowa method is adopted to calculate the strain and stress of the pipe respectively with or without internal pressure. One case of pipe subjected to the surface load of the Western Pipeline Company was chosen for the instance analysis calculation. The results show that he strain and stress of the pipe is larger and the situation of the pipe is dangerous when the pipeline is without internal pressure and the strain and stress is smaller when the pipe with the internal pressure. The reason is that the internal pressure improves the stiffness of the pipe in the round direction.