Does pipelaying method affect the development of pipeline geohazards and maintenance cost? A case study of Zhongxian-Wuhan gas pipeline, China.

Pipeline laying optimization should consider not only the construction cost but also the maintenance cost. However, how to consider the maintenance cost in the early stage of pipeline laying is not fully clear and lacks in-depth research. In this paper, a classification system for pipelaying methods was proposed in terms of the spatial relations between pipeline and its site geomorphology as well as construction methods. A detailed statistic for both development and distribution of geohazards and pipelaying method of the Zhongxian-Wuhan gas pipeline was conducted on the basis of field investigations. With the statistics results, the correlations of pipeline laying methods, geohazard development was studied, and the results showed the geohazard development and distribution vary with different pipeline laying methods. In addition, the construction costs and maintenance costs of various pipelaying methods were estimated. Significant differences in the construction and maintenance cost were observed for different pipeline laying methods. From the perspective of engineering practice, the construction cost and long-term maintenance cost must be synthetically considered in the early stage of pipeline laying in the high geohazard risk areas. [ABSTRACT FROM AUTHOR]