Earthquake proof engineering
The aim of this proposal is design Earthquake proof pipeline to transport oil and gas between countries as well as across the sea. The design in place signifies the two pipelines as a single unit with one diameter, which is the sum of the diameters as well as the distance between the two pipes. This design procedure has not been investigated exhaustively, and its validity can therefore, not be determined (Braza, Chassaing, & Ha Minh 1986 p. 86).
Some of the major significance of this study focuses on, is the interaction between fluid and a structure, which occurs when fluid causes deformation of a structure. This deformation causes changes in boundary conditions in fluid flow. Oil may be produced region where there is frequent occurrence of earthquakes, which are destructive.to be economical all times earthquake-proof pipeline is required to transport this oil to useful parts. This is done offshore and thus requires good understanding of the structures and the fluid involved (Lei, Cheng, Armfield, & Kavanagh 2000, p. 1113).
Vertical and horizontal circular cylinders usually support the offshore structures. The other surrounding members influence oil flow around in the pipeline; this is due to hydrodynamic loading forces generated by waves from earthquakes (Liang & Cheng 2005, p. 25). The failure of the structures during earthquakes causes loss of substantial amounts of money in the form of the goods being transported and the labor used in production. Proper design of such structures to withstand the hydrodynamic loading and earthquake forces is thus mandatory. Therefore the objectives of the study are to propose recommendation for the design of the pipeline structure that will be able to withstand earthquakes.
The methodology used in this paper is the Case Study, which while focusing on the earthquake-proof pipeline employs both deductive and inductive reasoning by looking between the lines, and through comparison with relative events. The case study experience will then be equated with similar events across the globe to provide a critical twist on the literature generated.
2.1 Research Design and Approach
The research design is a correlational case study design utilizing cross-sectional survey methodology. This study cannot claim that one variable had caused the other. However, the correlational approach is appropriate and sufficient for the research questions to be adequately answered.
Data was collected through secondary sources including online libraries, peer reviewed journals, and prior researches closely related to the topic. Literature that was examined included that which is found in peer-reviewed scholarly and professional publications, including articles in journals, business and market reports, reports released by relevant agencies and organizations. The websites of official as well as private firms will be used for the analysis. Information about structurally strong properties can be available through government website. As this large volume of data is available from the reliable government sources, a strong base of the data can be made use of for the further analysis. For analyzing the data, suitable statistical and mathematical tools have been used. These include graphs, percentages, tabular analysis, indices, coloration and regression.
2.2 Reliability and Validity of the Research Methodology
Every research study demands to be monitored throughout its development process, in order to maintain the reliability and validity of the research established. As the research study is based on the strategy of content analysis; therefore, it has to keep in serious considerations that any utilized source is not supposed to be providing the wrong information (Hakim, 2000). For this, reliable and truthful sources must be gathered for establishing the study based on the approaches of authenticity. The literature of experienced researchers and professors is significant to cover this domain, which is expected to give data based on realism. The collection of reliable data is expected to follow the research a valid way of conclusion, from which the future researches may also be benefited sufficiently. Therefore, it has been estimated that the sureness of gathering reliable data must confirm the study as a valid and authentic source of information (Creswell, 2009).
Although earthquake are beyond the control of humans, mitigation measures can be taken to reduce the impacts if it does happen (Dayton-Johnson, 2004-2006). Prevention is better than cure, and all individuals should be involved in such practices. There are human activities that are known to trigger the action of the earth epicenter. For example, mining is known to destabilize the seismic plates whose imbalance trigger earthquakes. Such activities should hence be discouraged in the areas that are known to be prone to natural disaster. Earthquake is not the only threat to the people but also properties like gas pipeline. This is main reason for design of earthquake-pipeline. We have under taken case study of Shizuoka Gas oil pipeline withstood Seismic Measures of 9.0.
3.2 Case study
polyethylene pipe that that follows large ground displacement as shown in diagram below;Shizuoka Gas has used earthquake-proof polyethylene pipes that are low low-pressure main pipeline with high- and medium-pressure conduit pipes are weld-joined steel pipes. An earthquake with an average magnitude of 9.0 generated a tremor described as one of the deadliest natural disasters of the decade and modern history in the area. The tremor affected all structures from buildings to pipelines. However, the company was able to reduce consequences due to use of
intelligent gas meters which detected and sent inform to the control for shutoff as shown in the diagram below.The company had also installed
The system above was designed for detecting any unusual pressure and communicate real-time for shutoff. The system uses genetic algorithms to invert plane wave seismograms (Braunschweig, 1995, p.26). These methods have proven to be time consuming as well as require an extensive amount of knowledge of the environment in question. When no prior knowledge is known about the environment, sensors can be utilized to design control tasks. The reinforcement based learning system can be applied within these controls in order to monitor and adapt to new information (Stafylopatis and Blekas, 1997). The system was capability of collecting and processing data that can greatly aid in shutoff. The pipeline is installed by considering hydrodynamic forces resulting from small-amplitude harmonic oscillations.Flow upto a Reynolds’s number of around 2100 is considered laminar flow and that above 4000 is considered turbulent flow. When the Reynolds number falls between these two extremes, it corresponds to a transition phase where, the flow can exhibit laminar, turbulent, or intermittent flow characteristics. The wide fluctuations and waviness of earthquake could allude to the turbulence, or a phase of transition to turbulence flow property inside the pipe. Further to that, the fact that the friction factor of the pipe causes a marginal energy loss and thus a reduced pressure head difference could I turn be a limiting factor to properly evaluate the data and understand the flow process. These pipes were modeled as follows
Throughout engineering aspects the reliability is defines as a natural consequences of failure in the matter of subject. This reflect the “true “and “correct “principle was practice before formal in analyzing data collection and analyzing for failure thus usually be self evident and leads inevitably to design modifications [Smith, 2011]
The design of earthquake pipelines requires assessment of hydrodynamic forces on the individual pipes as well as on the pipeline bundle as a single object.In earthquake-proof pipeline it will be necessary to model flow through possible displacements. Earthquake induced displacements can come in many shapes and sizes and are often orientated at a skew angle to the main direction of the flow. It is very important to be able to predict this afflux with reasonable accuracy, particularly under displacement conditions. A comprehensive investigation of this problem was carried out by Shizuoka Gas. They decided to implement flexible pipeline together with intelligent shutoff meters which enables the oil/gas flow to stop flowing when there is a large displacement beyond stretch limits of the pipe involved.
Earthquake- proof pipeline modeling potentially is very significant due to the complexity of the problem only limited progress has been made to date. In essence, the problem is to be able to predict the displacements due to some earthquake for example to determine the effects earthquake of high magnitude on pipeline. The solution requires coupling the hydrodynamic forces modeling approaches with appropriate transport equations whilst allowing for the changing geometric boundary condition of the flow. Common current practice is to assume a single phase flow whereby the continuity equation is coupled with the continuity and momentum equations for the oil flow. Applying a two-phase flow approach should take account of the interaction between the oil flow and the earthquake movement.
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