The effect of the backfill on the integrity of a buried pipeline upon heavy-duty vehicle crossings

0572273 - ÚTAM 2024 RIV CZ eng C - Conference Paper (international conference)
Gajdoš, Lubomír - Šperl, Martin - Slížková, Zuzana - Drdlová, M.
The effect of the backfill on the integrity of a buried pipeline upon heavy-duty vehicle crossings.
Journal of Physics: Conference Series. Vol. 2568. Bristol: IOP Publishing, 2023, č. článku 012002. ISSN 1742-6588. E-ISSN 1742-6596.
[ICBMPT 2023. International conference. Building materials, products and technologies /26./. Telč (CZ), 23.05.2023-25.05.2023]
R&D Projects: GA TA ČR(CZ) FW01010021
Institutional support: RVO:68378297
Keywords : gas pipeline * pressure * buried pipeline
OECD category: Applied mechanics
https://doi.org/10.1088/1742-6596/2568/1/012002

The aim of this work was to determine stresses in the wall of a buried empty gas pipeline caused by the weight of backfill as well as by heavy-duty vehicles crossing the pipeline, and, on their basis to assess the applicability of protective sleeves. A buried pipeline with zero internal pressure of transported medium (empty pipeline) differs from an unburied pipeline by the vertical load due to the weight of the backfill which causes an ovalness of the circular cross section of the pipeline. This leads to the rise of through-wall bending stresses with the tensile stress at the outside surface at the 3 and 9 o´clock positions and compressive stress at the inside surface. At the 6 and 12 o´clock positions the stresses are tensile at the inside surface and compressive at the outside surface. The current depth of soil cover above gas pipelines is 0.5 m. For pipes DN500, t ~ 6.5 mm the through-wall bending stress is found to be σb ≈ ±10 MPa. In comparison with the yield stress of pipeline material, this stress is negligible. The situation is changed when heavy-duty vehicles cross the pipeline. For example, when a MAN truck with the mass load 3270 kg acting on a single wheel of the front axle crosses this pipeline, the pressure transmitted to the pipe will cause the through-wall bending stress σb ≈ ±76 MPa. This stress is superimposed to that of the backfill to give the total value ±86 MPa. When dead loads, imposed by backfill cover, together with live loads, caused by truck-wheel loads, are excessive a crushing of side walls of the pipeline and/or ring buckling of the pipe cross section can happen.
Permanent Link: https://hdl.handle.net/11104/0343022