Analysis On Mechanical Characteristics Of Buried Pipelines Under Surcharge Loads

In recent years, the buried pipelines has played an increasingly important role in many fields of modern industry, agriculture production and our daily lives. And it has been the focus of many civil engineering areas. Safely accident in buried pipelines happened frequently. There are many factors for these accidents, which surcharge loads is inevitability. So this thesis mainly makes a research and study of surcharge loads on buried pipelines. Some useful conclusions are obtained in the thesis. The main content of the thesis is as follows:1. Through analyzing current status and evolutionary trend of buried pipelines in domestic and abroad, the discussion about the damage of surcharge loads on pipelines were performed. This thesis systematically summed up the history and present status of buried pipelines as well as the different damage forms of pipelines.2. The deformation and stress of buried pipelines which occurs by ground soil were expounded. And then the distribution of the distribution field, and the stress field of the foundation with overburden and characteristics of the transmission of forces were analyzed. According to the research of the calculation methods at the present of the stage, the paper summarized the pattern of pipeline-soil interaction so as to provide theoretical references for next numeric analysis.3. A calculation model was established based on the theory of Winkler elastic foundation short beam, taking into account the impact of soil deformation which is leaded by adjacent surcharge loads. The Boussinesq basic formulas and the finite difference method were also applied. Consequently, analyses were performed for pipelines varying the load location, geologic condition, pipeline depth, diameter and stiffness through an example. In this thesis, the large FEM software, ABAQUS, was employed to simulate the mechanical characteristics of buried pipelines as an additional analyses for the third chapter, which mainly focus on the pipelines self-weight, material and the characteristics of the substratum. The results can provides a basis for the protection of buried pipelines.4. Based on the theoretical analysis and simulating calculation, pipeline protection and control measures were summarized systematically.So it is necessary to consider the surcharge loads and make a reasonable protective measure for buried pipelines. It’s hoped that the work in this thesis can supply technical support and guidance to the design and protection of buried pipelines. The achievements in task research may have an immediate utilization in close projects. Also the study method provides reference for developing and researching similar projects.