To the question of determining bending stress of a buried pipeline from the ground surface

Abstract

The laying of buried pipelines in difficult engineering and geological conditions is associated with the need to take into account a large number of factors affecting the process of pipeline operation. It is practically impossible to take into account all these factors at the design stage. In this regard, methods that make it possible to assess the technical condition of the pipeline at a specific point in time acquire particular relevance. One of the promising methods for assessing the technical condition of underground pipelines is to survey the depth of the axis of the underground pipeline from the ground surface with subsequent use of the data obtained to assess the level of bending stress. The low popularity of this method lies in the large errors obtained in the calculations according to the developed methods. In the work, the reasons for the occurrence of significant errors in determining bending stresses when using survey data were analyzed, mathematical dependencies were proposed that make it possible to evaluate bending stress based on the data obtained with the accuracy specified at the design stage of the experiment. Calculations are provided that confirm the adequacy of the proposed mathematical models.

Improving the method for assessment of bending stresses in the wall of an underground pipeline

“…The main problems and opportunities for modernizing this technique are described in the work [33]. The main limitation of all existing methods is the use of the maximum depth in the control area when performing calculations, as well as the fixed error of the trace finder in the entire control area.…”

“…Research methodology. Refinement of a mathematical model similar to that described in the source [33], is associated with the need to search for a large amount of data for the selection of regression coefficients. These data can be obtained by modeling the elastic bending of a pipeline section with fixed parameters.…”

“…These data can be obtained by modeling the elastic bending of a pipeline section with fixed parameters. The work uses data similar to those used in the work [33], with the addition of several new input variables. A detailed diagram of the model is described in the materials [25,32,33].…”

“…The work uses data similar to those used in the work [33], with the addition of several new input variables. A detailed diagram of the model is described in the materials [25,32,33].…”

“…Current frequency during measurements is 640 Hz, according to the recommendations of the source [38]. The interval between studied depths of one meter was adopted by experts in order to fix statistically significant differences based on the results of the work [25,33]. An example of measurements results carried out in accordance with the described provisions is presented in Table 2.…”