To ensure reliability of the main pipeline during operation it is necessary assessing the strength of the pipeline that is subjected by a complex of loads. The stress-strain state monitoring of the pipeline contributes to the solution of this problem since the values of stresses (strains) obtained during monitoring are the initial data for pipe strength calculations. Continuous assessment and monitoring of the stress-strain state is especially necessary for main pipelines laid in difficult geological and engineering conditions. Various methods are known either for assessing the pipeline stress-strain state that consist of determining the spatial position of the main pipeline and further calculating the stress-strain state components or in directly measuring stresses or strains by some physical method. It is important that the method provides continuous pipeline monitoring.
In this article, an inclinometric technology is proposed to determine the spatial position and curvature of the main pipeline. The technology was tested in laboratory conditions on the bench that is a pipe installed on two supports. The laboratory bench allows loading the pipe with a bending force in the vertical plane. In the experiments, a portable digital inclinometer was used, it measures inclination angles of the pipe during bending. Plots of the tangent of the inclination angle, deformation and curvature of the upper, lateral and lower pipe zones are obtained. Therefore, the inclinometric method is effective. The data of inclinometric measurements allow calculating the components of the pipeline stress-strain state according to known formulas. Guidance on implementation of inclinometric technology in practice for monitoring the pipeline stress-strain state including specifying the installation location of inclinometric sensors on the pipeline is given. Inclinometric sensors provide continuous monitoring of the main pipeline position and assessment of its stress-strain state.
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