Assessment of Delay Factors in Saudi Arabia Railway/Metro Construction Projects

Railway construction industry has devoted vast amount of resources into advancing the management and technology of railway construction, yet most project in this industry often failed to comply with the set deadlines and budget limits. This study was conducted to recognize the critical factors that are causing delays in the construction of Riyadh Metro project, Saudi Arabia. From a thorough literature review, thirty-six (36) factors causing delays were identified which were then distributed to qualified industry experts in a survey questionnaire. A total of 105 respondents were gathered during the data collection. The data was then evaluated statistically by utilizing different calculation tools that are frequency adjusted importance index for the delay factor ranking, and Spearman's correlation coefficient for the link between two different set of data. The result of this research identified the top five main delay factors to the railway construction projects which are “Client's decision-making process and changes in control proceduresâ€, “Design Errors (including ambiguities and discrepancies of details/specifications)â€, “Labor skills levelâ€, “Design changes by Client or Consultant†and lastly, “Issues regarding permissions/ approvals from other stakeholdersâ€. Finally, this study is hoped to help the railway construction industry in bettering itself by highlighting which issues should be focused on to counter the delays and reduce downtimes

Enablers for integrated operations diagnosis and improvement

In order for organizations to improve their performance, they shall identify their operations opportunities for improvement. The process to identify the opportunities for improvement is referred herein as “diagnosis” process. The most common systematic operations diagnosis and improvement approaches are Quality Audit, Organizational Assessment based on Business Excellence Framework and Project Selection for Lean and Six Sigma. All these three approaches should be integrated in order to grasp the fruitful benefits for the organizations. The benefits include; minimize redundancies, improve the operations performance and eventually assist in achieving certification and award. This paper proposes the enablers for operations diagnosis and improvement based on integration of ISO19011 Quality Audit framework, Business Excellence Framework and Lean Six Sigma approaches

A Systematic Review of the Concrete Durability Incorporating Recycled Glass

This systematic literature review (SLR) aims to present and analyze the recent research on the effect of recycled glass (RG) on the durability of concrete applications in terms of transport properties, chemical attack, alkali-silica reaction (ASR), and freeze/thaw (FT). RG could be utilized in concrete as a replacement or addition in three forms, namely glass powder (GP), glass aggregate (GA), and glass fiber (GF). The methodology of this study was based on a criterion for the selection process of reviewed studies to assess and synthesize the knowledge of the durability of RG in concrete. The articles were assessed and screened, then 114 review articles were selected. The direction of utilization of RG in concrete depends on the type, particle size, and pozzolanic performance. The valorization of RG had a positive impact on the durability of concrete; however, the mutual synergy of multiple substitutions with glass also had better results. Nowadays, fine glass aggregate (FGA) could be promoted to be used as a partial substitute for sand due to the easiness of recycling. Furthermore, GF is strongly encouraged to be used in fiber concrete. An analytical framework that highlights the durability improvement of glass-modified concrete is presented. The results suggested that it is technically feasible to utilize glass as a part of concrete in the production of durable concrete. It provides a higher resistance to transport properties and chemical attacks by providing an extended lifespan. In addition, RG plays a great role in FT action in cold climates while it does not have a significant impact on ASR, provided refinement of glass results in the reduction of ASR and thus overcomes the expansion and cracks of concrete. However, up to 20% GP and up to 30% fine glass aggregate (FGA) could be replaced with cement and aggregate, respectively, to achieve a positive effect on durability based on the W/C ratio provided, not compromising the strength

Analysis of BIM-Based Digitising of Green Building Index (GBI): Assessment Method

There is currently an increasing demand for Building Information Modelling (BIM) to be integrated into green projects. BIM is able to evaluate green building assessment tools by digitising and assessing buildings during their development stage. In Malaysia, the Green Building Index (GBI) promotes sustainability in the built environment. Six categories of criteria will be assessed in three of the certification stages. This study focuses on how BIM applications can digitise the GBI criteria for GBI processes. It examines BIM uses and tools of each GBI credit and defines the responsibility and role of construction stakeholders in using BIM to examine the assessment methods used for new non-residential building construction based on GBI. The primary method for data collection is the focus group interview which involves the groups of stakeholders involved in a BIM and GBI project. The result of the BIM–GBI assessment method showed that BIM could digitise and assess 25 credits in Design Assessment (DA), which can achieve 55 points of the total 100 points. This study helps stakeholders define the design team and facility manager’s roles to obtain GBI certification and maintain the certification during the building’s operation stage

Copy number variation of Fc gamma receptor genes in HIV-infected and HIV-tuberculosis co-infected individuals in Sub-Saharan Africa

AIDS, caused by the retrovirus HIV, remains the largest cause of morbidity in sub-Saharan Africa yet almost all genetic studies have focused on cohorts from Western countries. HIV shows high co-morbidity with tuberculosis (TB), as HIV stimulates the reactivation of latent tuberculosis (TB). Recent clinical trials suggest that an effective anti-HIV response correlates with non-neutralising antibodies. Given that Fcγ receptors are critical in mediating the nonneutralising effects of antibodies, analysis of the extensive variation at Fcγ receptor genes is important. Single nucleotide variation and copy number variation (CNV) of Fcγ receptor genes affects the expression profile, activatory/inhibitory balance, and IgG affinity of the Fcγ receptor repertoire of each individual. In this study we investigated whether CNV of FCGR2C, FCGR3A and FCGR3B as well as the HNA1 allotype of FCGR3B is associated with HIV load, response to highly-active antiretroviral therapy (HAART) and co-infection with TB. We confirmed an effect of TB-co-infection status on HIV load and response to HAART, but no conclusive effect of the genetic variants we tested. We observed a small effect, in Ethiopians, of FCGR3B copy number, where deletion was more frequent in HIV-TB co-infected patients than those infected with HIV alone