Effect of heavy-duty vehicles riding over buried pipes on stress in the pipes
The contribution describes and discusses the results of theoretical and experimental research into the changes in the deformation and stress in the walls of a buried gas pipeline caused by heavy-duty vehicles riding over it, in particular as regards the use of casing on high-pressure gas pipelines.
Over the entire circumference of a DN 500 pipe of L360NE steel, specifically in the 12, 3, 6 and 9 o’clock positions, relative deformations were strain gauged in the circumferential and longitudinal directions; the measurements covered a range from the condition of the pipe when buried in the excavation and backfilled until the riding of a vehicle over the pipe when empty and then when pressured up to 5.5 MPa and 5.2 MPa.
The measured deformations served as input data for calculating the values of hoop and longitudinal stress over the circumference of the pipe, and the net effect of vehicle rides was determined from them.
Considering the hoop stress in the 12 o’clock position, the stress caused by the vehicle riding over the empty pipe is less than –5 MPa based on the strain gauge measurements, and it is –9.4 MPa based on approximate calculations. This effect is even weaker for the pipe under pressure.
The results show that the effect of external load caused by vehicles does not constitute any extreme risk in terms of overall stress in the pipeline.
Read more in the article Effect of heavy-duty vehicles riding over buried pipes on stress in the pipes (PDF, Czech language, 2060 kB).