Chapter 3. Methodology
The main focus of this chapter is based on the methodology used in this thesis to achieve the research objectives. Firstly some methods of research classification will be briefly discussed and general procedures for conducting research will be explained. In this chapter research philosophy, case study method and application of this method in this study will be discussed.
The purposeful research can be classified as the following 6 classes: exploratory, descriptive, causal, correlative, interpretive and critical. Concepts and problems can be clarified by exploratory research, and a method can be applied in order to show the project feasibility or test the preliminary idea. Descriptive research intends to accurately describe the research topic. When researchers are concerned with explanation rather than description, a causal research method is applied. The purpose of correlative research is to correlate regularities for future prediction. Human intention and the meaning of events to those involved can be extracted by interpretive research, while critical research is applied to demystify social behaviours (Tan, 2004)
In terms of purposeful research this study can be classified as exploratory and causal. In showing the seismic vulnerability of unpressurised wastewater networks in earthquake prone cities in New Zealand is exploratory and is the first purpose of this research. The other two purposes of this research are to find factors which can affect seismic vulnerability of wastewater pipeline and to compare different fragility curves in the case studies, thus this research can be classified as causal.
Research is also classified into two broad categories, quantitative and qualitative (Dawson, 2002). However, Dooley (2002) believes that the qualitative and quantitative description refer to two types of data and cannot be used to classify research types (Dawson, 2002).
According to Creswell (2002), research can be classified into qualitative and quantitative with the same research process. A typical research work comprises of the following 6 stages, i.e. identifying the problems, reviewing the existing literature, selecting participants or samples, collecting data, analysing and interpreting the data and finally reporting and evaluating the research findings (Creswell, 2002).
Yin (2003) classifies research strategies into the following 5 categories; an experiment, a survey, an archival analysis, history and case studies. Table 3.1 presents a comparison between different types of research methods.
The research philosophy
Research philosophy guides researchers to choose an appropriate method and shows which data should be collected, analysed and used (Davison, 1998). The qualitative/quantitative research classification lacks coherent definition and focuses on methods rather than exploring underlying research philosophy. Therefore, research methods described and classified by a philosophical approach is a basic research classification (Clarke, 1998).
Research philosophy can be divided into two broad methods: positivist and post-positivist (Crossan, 2003). In positivist research, prediction is based on the foundation of the previously observed and explained realities and their inter-relations. This method is based on the idea that reality is stable and can be observed and described from an objective viewpoint (Davison, 1998). In this method the researcher is objective and acts independently. The positivist researcher does not influence research results and data is achieved by observation or experimentation (Tobin, 2006). From the positivist point of view, reality is objectively given and is measurable by properties which are independent of the researcher. In this method, quantitative data is used to describe the parameters and their interrelationships (Tobin, 2006).
Nonetheless, the positivist approach provides useful but limited data that only provide superficial view of the phenomenon which is investigated (Crossan, 2003). Some researchers such as Jacob Bronowski (1956) and Karl Popper (1959) believe positivist philosophy provides elementary justification and a new method is required to overcome this deficiency (Crossan, 2003). Post-positivism provides an alternative to the traditions and foundations of positivism for conducting disciplined inquiry. For the post-positivist researcher reality is not a rigid construct, instead it is a creation of those individuals involved in the research. From this perspective, reality does not exist within a vacuum, its composition is influenced by its context, and many constructions of reality are therefore possible (Ramsay, 1998).
Post-positivism is used to prove the existence of a phenomenon in contrast to positivism which makes claims to absolute truth through the establishment of generalisation and laws. According to Doyal (1993) the apparent certainty and high probability in knowledge achieved by a positivist view is an illusion because it cannot be proved to apply in all situations. Similarly, some issues in research observation and experiment which were thought to be true previously have been discovered to be false (Doyal, 1993).
While quantitative research is used to investigate phenomena in the positivist approach, in post–positivism a qualitative perspective is used to describe and explore phenomena in depth, however, both qualitative and quantitative data can be applied in post-positivist methods (Ford-Gilboe et al., 1995). In spite of opposing and polarised methodologies in qualitative and quantitative research, these are frequently used together and complement each other. Furthermore, the distinction between the philosophies is overstated and triangulation of methods is common (Webb, 1989).
From a positivist perspective, theory verification is the main goal, whereas, theory falsification is the key purpose of post-positivist research. Nonetheless, both methods are applied for explanation which leads to prediction and control of phenomena (Ponterotto, 2005) Research can also be categorised as empirical and non-empirical. Previous research and the pre-existing body of knowledge are essential for conducting research in a particular field of study. When research depends entirely upon on the previous research it is classified as non-empirical. Alternatively, when research is based on observation and experiment it is categorised as empirical research (Tobin, 2006).
Chapter 1. Introduction
1.1. Wastewater system components
1.3. Research overarching aim
1.4. Research questions
1.5. Research objectives
1.6. Structure of the thesis
Chapter 2. Seismic damage and methods of damage estimation in buried pipeline networks
2.1. Wastewater system components
2.2. Earthquake effects on the wastewater system
2.3. Summary of seismic damage in buried pipelines
2.4. Calculating earthquake effects on buried pipelines
2.5. Critical parameters affecting the pipeline damage rate
2.6. Type of defects in wastewater pipelines
Chapter 3. Methodology
3.2. The research philosophy
3.3. Application of the case study research strategy
3.4. Research design
Chapter 4. Hutt City case study
4.1. Hutt City
4.2. Hutt City wastewater pipeline
4.3. Wave propagation damages in the Hutt City wastewater network
4.4. Comparison and outcome
4.5. Comparison of the calculated defects with real observation
Chapter 5. Gisborne case study
5.1. Active faults and seismic vulnerability in Gisborne,
5.2. The 2007 Gisborne earthquake concurred
5.3. Gisborne wastewater network
5.4. Overall effects of earthquakes on the Gisborne wastewater network
5.5. Earthquake effects (wave propagation) on the Gisborne wastewater network
5.6. Comparison of calculated data with observed data
Chapter 6. Blenheim case study
6.1. Seismic vulnerability and active faults in Blenheim,
6.2. Wastewater pipelines in Blenheim
6.3. Overall earthquake effect on Blenheim wastewater network
6.4. Wave propagation effects of earthquakes on the Blenheim wastewater network
6.5. Comparison of the calculated defects with observed damages
Chapter 7. Wastewater pipelines damage: comparison and discussion
7.1. Comparison of wastewater network in three case studies
7.2. Study limitations
Chapter 8. Wastewater network damage and repair in the 2010 Christchurch earthquake
8.1. The 2010 Christchurch earthquake
8.2. The 2010 Darfield earthquake effects on the Christchurch wastewater system
8.3. The Christchurch earthquake effects on the wastewater pipelines
8.4. Calculation of seismic effects on the Christchurch wastewater network
8.5. Correlation of the seismic damage to the earthquake parameters
8.6. Rehabilitation process for wastewater networks in New Zealand
Chapter 9. Conclusion
9.1. How the objectives were achieved
9.2. Contribution to knowledge
9.3. Practical implication
9.4. How the overarching aim of the thesis is achieved
9.5. How the thesis‟s findings can be applied for improvement in fragility curves
9.7. Future Work .
GET THE COMPLETE PROJECT