A Determining Method of Longitudinal Mechanical Response of Buried Pipelines Caused by Uneven Ground Subsidence

Abstract

The invention relates to a method for determining the longitudinal mechanical response of a buried pipeline caused by uneven stratum settlement. First, the bending stiffness and foundation elastic coefficient of a longitudinal elastic foundation beam model of the pipeline are determined, and then the cumulative settlement value of the stratum where the pipeline is located is drawn in a coordinate system. , and fit the curve, and then determine the calculation model of the longitudinal mechanical response of the buried pipeline caused by uneven stratum settlement, and then determine the bending moment and shear force of the pipeline section at the suspended section and the grounded section in turn, the suspended section and the grounded section. The shear force, bending moment, rotation angle and settlement expressions of any section of the pipeline are obtained. Finally, the Fourier cosine series expansion of the cumulative subsidence term of the formation is carried out, and the Fourier series expansion of the formation subsidence term and the corresponding Fourier coefficient are used. , and determine the bending moment, shear force and settlement of any section of the suspended and grounded sections, respectively. The invention can more accurately determine the longitudinal mechanical response value of the buried pipeline under the influence of uneven stratum settlement, and provides a basis for the longitudinal design of the pipeline.

Description

technical field [0001] The invention relates to the technical field of construction engineering, in particular to a method for determining the longitudinal mechanical response of a buried pipeline caused by uneven ground settlement. Background technique [0002] Buried pipelines are an important part of infrastructure for transporting natural gas and crude oil, and play a pivotal role in social production and life. They are called "lifeline projects". There are more and more problems of stratum subsidence induced by subway tunnel construction, excessive groundwater extraction and mining of underground mineral deposits, which pose a serious threat to the long-term safe operation of buried pipelines. [0003] The European Gas Pipeline Incident Data Group (EGIG) has counted the natural gas pipeline accidents in European countries from 1970 to 2010, of which the proportion of natural gas pipeline accidents caused by surface movement reached 7.4%. The formation subsidence will c...

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Problems solved by technology

[0004] However, studies have shown that the characteristics of the pipe-soil interaction are related to the cumulative settlement of the strata where the pipe is located. When the soil around the buried pipe undergoes a large deformation, affected by the pipe-soil deformation stiffness, the settlement value of the pipe is less than that around the pipe. Soil, the pipeline in the subsidence area of ​​the ground will be separated from the surrounding soil, that is, there will be partial suspension and partial contact. The elastic foundation model with complete contact does not conform to the actual deformation of the soil around the pipe, and cannot reflect the actual force of the buried pipeline. and deformation

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