Risk Assessment of Urban Gas Pipeline Based on Different Unknown Measure Functions

Several risk factors threaten the safety of urban gas pipeline. How to effectively identify various risk factors affecting urban gas pipeline and put forward scientific risk assessment method is the focus in the field of urban safety research. To explore the uncertain factors in the process of gas pipeline risk assessment, and propose a practical assessment method, a three-layer index system for the risk assessment of urban gas pipeline was established using unascertained measure theory, which included 5 first-class evaluation factors and 34 second-class evaluation indexes. Four unascertained measure models (linear, parabolic, exponential and sinusoidal) were constructed, and the unascertained measure values of each evaluation index under four unknown measure function models were calculated. The weight of evaluation factors was determined by Analytic Hierarchy Process (AHP), and the confidence criterion was used for discriminant evaluation. Results demonstrate that the risk assessment models constructed with different measurement functions can effectively reduce the uncertainty of urban gas pipeline risk assessment, but for the same object, the risk level of the linear measurement model in 4# pipeline is lower than other measurement functions, and the risk level of sinusoidal measurement model in 8# pipeline is higher than other measurement functions. Therefore, considering the evaluation results under different measure functions and focusing on monitoring objects with different results is necessary when using unascertained measure theory for risk assessment. The conclusions obtained from this study clarify the application conditions of unascertained measure theory in urban gas pipeline risk assessment, which helps to reduce the uncertainty in the assessment process and improve the accuracy of the assessment results

Risk Level Evaluation on Construction Project Lifecycle Using Fuzzy Comprehensive Evaluation and TOPSIS

A risk is a predominant problem in the developing countries construction projects. Although numerous studies have been concerned on risk, there is a limited study on a mechanism to identify the typical risks and effects level. This paper presents an approach for evaluating the risks in case of schedule delays at the various lifecycles of construction projects. The methodology applied is an integrated model of the technique for order preference by similarity to ideal solution (TOPSIS) and fuzzy comprehensive evaluation (FCE). In this study, common criteria, sub-criteria, and attributes are constructed to make a decision concerning the influence level of risk of delay at the construction project lifecycle. The results showed that the construction stage (44%) is highly influenced, the second highly influenced stage is post construction (37%), and the least risked stage is pre-construction (35%). The construction projects in Ethiopia have faced an average delay risk of 38% at a high and very high-risk level. This work is expected to serve as a tool to assist managers in the management and control of schedule delays to mitigate their risks

Examination of the Relationship between External Environmental Conditions and Construction Project Failures in Countries of Northern Africa

The construction industry is an essential and supportive pillar of national economies in Northern Africa making construction project management a dynamic arena. Construction project success is dependent on how well project managers recognize and manage project constraints versus negative risk impacts. The purpose of this qualitative research was to explore and describe the impacts between external environmental conditions and construction project failures in countries of Northern Africa. Data was sourced from construction project managers that operate within this region. Data collected focuses on the interdependencies between negative risk impacts from external environmental conditions and construction project failures. An analysis of the collected data reveals emergent themes, influence drivers as well as risk management approaches. The identified emergent themes and influence drivers could assist construction project managers with managing negative risks by selecting optimal risk mitigation approaches. Successfully implementing construction projects in Northern Africa may assist firms to better allocate funds and execute strategies to strengthen these national economies

Critical delay factors in housing construction projects in Saudi Arabia: assessment and solutions

Given the Kingdom of Saudi Arabia’s (KSA) current housing shortage, the government recently made substantial investments in public-sector housing projects across the country. To maximise the efficiency of these investments, the problem of construction projects delay must be overcome. Therefore, this research project identified delay factors in public-sector housing construction projects in the KSA, and proposed solutions for mitigating or avoiding the construction delays. The main aim of the study is to assess housing projects in the KSA, in terms of delays in the construction phase, and to develop a comprehensive framework based on the analysis of the delay factors (such as client-related, consultantrelated, etc.) to mitigate or prevent their occurrence. The study highlights the importance of delays in construction and provides a complete review of issues of importance in terms of concepts, principles and challenges. In addition, the literature was reviewed through an effective survey to find out the causes of delays in order to build general knowledge of delayed construction projects. A mixed-method research design was adopted involving a literature review, surveys, interviews and case studies. The primary data focused on the delay factors contributing to housing projects delay in the KSA’s construction industry, as well as viable solutions. Data analysis involved descriptive statistics and thematic analysis, and the participants were clients, consultants and contractors in the KSA’s construction industry. Consequently, more than 80 delay factors were identified, then classified into 10 groups and ranked in terms of their severity. A conceptual framework has been developed to advise on the processes that stakeholders should embrace in housing construction projects. Whereas, the solutions identified were used to generate an evidence-based framework, which practitioners can use to mitigate or avoid delays in housing projects. Key aspects of the solution may include the use of building information modelling (BIM), review and assess the government's role in housing projects. Furthermore, all stakeholders should take measures to prevent and reduce delay in housing projects, by promoting FIDIC contracts, establishing an independent planning board, integrating training and awareness initiatives, and eventually implementing the proposed conceptual framework

A framework to enhance the adoption of building information modelling amongst Sri Lankan quantity surveying organisations to increase the accuracy of pre-tender cost estimates

For decades, construction projects around the globe have been suffered to complete on budget due to ongoing cost overruns. Accordingly, both developed and developing countries have reported a number of construction projects that have resulted in increased initial project costs. As a result, several studies have been undertaken to investigate the causes of cost overruns and found that inaccurate project cost estimates are a major reason for project cost overruns. Conventional tasks, such as manual quantity take-off, the use of 2D drawings, and a lack of information that are embedded within the process when preparing cost estimates, were found to be challenging to produce accurate cost estimates. Nevertheless, through the use of Building Information Modelling (BIM) many countries, both developed and developing, have been able to prepare accurate cost estimates by overcoming the consequences of conventional cost estimation practices. Many BIM adopted countries have identified drivers and barriers as part of the BIM adoption process and been able to develop BIM frameworks to enhance its adoption. Many studies indicate that BIM is a buzzword for the Sri Lankan construction industry and placed in BIM level 0. Majority of the quantity surveying organizations are lagging behind of adopting BIM to improve the accuracy of pre-tender cost estimates. Therefore, BIM adoption among quantity surveying organisations has often been criticised, as many have not yet adopted BIM within their practice. Although the literature indicates the importance of a nationally developed BIM framework, Sri Lanka not yet developed a BIM adoption framework by identifying national wide barriers and solutions. Accordingly, this research seeks to explore the issues behind non-BIM adoption to resolve the issue. This research inquiries into the drivers and barriers to BIM adoption, in order to provide affordable solutions. Thus, a framework if proposed to enhance BIM adoption, by identifying the gaps in BIM adoption (drivers and barriers) and the mitigating actions required to overcome these barriers. And the selection of a specific developing country would permit an in-depth understanding of the process of BIM adoption; thus, Sri Lanka was selected for the proposed purpose of this research.This study adopts an explanatory, sequential mixed method that applies a questionnaire survey and a semi-structured interview within a case study. The case study and survey data were collected separately in Sri Lanka from June 2017 to January 2018. The collected quantitative data was analysed descriptively and ranked using a relative important index analysis. The qualitative data were analysed using a thematic analysis technique to identify the themes and patterns. The results show that only a few QS organisations have adopted BIM. Nevertheless, it was found that six major drivers, namely BIM benefits, client demand, professional bodies, BIM-related training, organisational pressure, and BIM education, influence organisations to adopt BIM. Moreover, the use of a BIM model, automated quantity take-off, improved visualisation, improved information management, clash detection and timesaving were the highlighted as the key BIM benefits for QS organisations. In the meantime, the findings further identified the interrelationships between major drivers. Besides, six major barriers were also identified, namely financial, organisational, unawareness, the lack of market demand, the lack of resources, regulatory issues, and sub-factors, which hinder the adoption of BIM. In the meantime, findings further revealed the root causes for each barrier and identified interrelationships between the major barriers. Moreover, mitigating actions to overcome the impact of the barriers and their root causes were also identified. The analysis further showed that some of the empirical findings replicate those in similar contexts reported in the literature for other countries.A framework was produced and presented at the end of the thesis, which was designed to enable plausible means to overcome the impact of the barriers found. The proposed framework is expected to benefit quantity surveying organisations, architects, and other construction industry-related professionals to evaluate their strengths in BIM adoption (drivers) and to mitigate the impact of barriers that lead to the non-adoption of BIM. It is also expected to benefit construction-related professional bodies, governments, and academics by determining their role in support of BIM adoption