Comparative analysis of mechanical response of buried steel pipeline under different settlement processes

Objective With the acceleration of China's oil and gas pipeline and urban construction process, the settlement disasters of buried oil and gas pipelines are gradually increasing and widely distributed in China, and geological subsidence has become one of the key disaster types threatening the safety of buried oil and gas pipelines. Methods In order to study the differences in mechanical response of buried steel pipes under different settlement development processes (settlement modes), settlement simulation experiments of buried steel pipes under different settlement modes were conducted, and the differences in mechanical response of buried steel pipes under different settlement modes were quantitatively analyzed. Results The research results indicate that for the same geological settlement results, different settlement development processes will cause different mechanical response states of buried steel pipes. The mechanical response of buried steel pipes under the overall settlement mode of soil is more severe compared to the multi-stage multiple settlement mode, and the pipes are more prone to damage due to settlement. In addition, although the maximum settlement of the soil surface directly above the buried pipeline in the reverse settlement mode is always greater than the maximum settlement of the soil surface directly above the pipeline in the overall settlement mode, the mechanical response of the pipeline is always smaller than that in the overall settlement mode. 【Conclusion】 Therefore, for the safety evaluation of buried pipelines under settlement, the significant local soil settlement in geological settlement may not have a significant impact on the overall pipeline, and it is necessary to consider the development process of soil settlement in the entire settlement zone uniformly. In the disaster of buried pipeline settlement, efforts should be made to control the soil settlement in different areas of the stratum settlement zone as much as possible to reduce the mechanical response of the buried pipeline and ensure its safety. For the settlement results of the specified settlement range and amount, in order to minimize the mechanical response of buried steel pipes under the action of settlement, it is recommended to first perform a relatively large range of soil settlement in the middle of the settlement zone, and then perform multiple small-scale soil settlements towards the boundary of the settlement zone. The research results of this article are of great significance for accurately evaluating the safety of buried pipelines under geological subsidence. (Figure 31, Table 8, Reference 20)