Study of crack problems in water-main pipe lines
Boon, Kok Eng
Date of Issue2017-04-19
School of Mechanical and Aerospace Engineering
Nowadays, pipelines have various uses; water and energy supply systems, communication services and so on. Furthermore, the pipelines are affected by many types of load in various parts of the world. Our pipe failure may include fracture, distortion, corrosion and erosion that can cause the pipeline to have crack problem like longitudinal or circumferential crack. In the early year, PUB, our Singapore National Water Agency has been providing an efficient, adequate and sustainable supply of water at affordable cost. Accountability for water supply distribution is important by reducing losses with full leakage controls and accurate metering in existing network management. Singapore is one of the countries that achieved only 5% which has the lowest Unaccounted-For-Water (UFW). There are two parts in this project. First part will be deal with study of relationship between crack tip opening displacement, crack depth, crack height and semi-major axis ratio. Secondly, in the case study of a buried pipeline, the characteristic of soil is not uniform (Watkins and Anderson, 2000). Thus, it is necessary to assess the static loads for pipeline with likely of buried pipeline behaviour. This project examines the typical pipeline behaviour caused by static loads in accordance with soil types. Assessments about how a buried pipeline behaves in accordance with soil types and load types are made throughout this work by finite element method (FEM) for buried pipeline. It has included the studies of the effect of stress and displacement of buried pipe line under static loads. 1500mm diameter with 20mm thickness of Steel pipe is used. (Outer diameter is 1524mm inclusive of cement lining) The depth of 1, 2, 3, 4, 5, 6 m of buried pipe from ground surface is chosen in the experiment. Finite element analysis (FEA) of pipeline and soil are interpreted using ABAQUS software. The results had indicated that if there is an increase in depth, it will decrease the displacement for buried pipeline.
Final Year Project (FYP)
Nanyang Technological University