Paul McMahon

Purpose: The relative low capital cost and contributions to mitigating global warming have favoured the continuous construction and operation of nuclear power plants across the world. One critical phase in the operation of nuclear plants for ensuring safety and security of radioactive products and by-products is decommissioning. With the advent of digital twinning in the building information modelling (BIM) methodology, efficiency and safety can be improved from context-focus access to regulations pertaining demolition of structures, and cleaning-up of radioactivity inherent in nuclear stations. A BIM-driven framework to achieve a more regulation-aware and safer decommissioning of nuclear plants is proposed.
Design: The framework considers task requirements, and landscape and environmental factors in modelling demolition scenarios that characterise decommissioning processes. The framework integrates decommissioning rules/regulations in a BIM linked non-structured query system to model items and decommissioning tasks, which are implemented based on context-focused retrieval of decommissioning rules and regulations. The concept’s efficacy is demonstrated using example cases of digitalised nuclear power plants.
Findings: This approach contributes to enhancing improvements in nuclear plant decommissioning with potential for appropriate activity sequencing, risk reduction, and ensuring safety.
Originality: A BIM-driven framework hinged on querying non-structured databases to provide context-focused access to nuclear rules and regulations, and to aiding decommissioning, is new.

Design/methodology/approach This research has measured, using National Student Survey (NSS) criteria, student experiences on an interdisciplinary project on a civil engineering programme. It benchmarks the quality of learning and student understanding and perceptions of learning. The method is based upon a literature review and questionnaire survey of students.
Purpose In line with business goals of customer satisfaction, higher education institutions of learning consider excellent student experience a priority. Teaching and learning are important aspects of satisfaction that are monitored annually by universities using tools such as the NSS. NSS results are useful for educational planning and informing consumer choices. This research measured undergraduate student experiences on an interdisciplinary project using the NSS framework. Hinged on diversity, the purpose was to investigate whether full time, part time and degree apprenticeship students with varied work experience enhance their learning studying together on an interdisciplinary project.
Findings Results indicate good amounts of peer influence on learning in a simulated interdisciplinary team setting supported by a mix of diverse work experience in students’ background.
Originality/value Sections of the NSS are extended with additional questions to capture the impact that full-time, part-time and degree apprenticeship study modes, closely associated with students’ background of job experience, have on teaching and learning.

This paper presents results of a comprehensive investigation on the utilization of carpet waste fibers in reinforcement of clay soils. Effects of adding proportionate quantities of two different types of shredded carpet waste fibers to clay soils (i.e., 1, 3, and 5% by dry weight of the soil) were investigated and evaluated. The investigation was conducted on specimens prepared at their maximum dry unit weight and optimum moisture content, as well on specimens prepared at variable conditions of dry unit weight and moisture content. A comparison was also made on specimens prepared at the same fiber content by changing dry unit weight while moisture content was kept unchanged or by changing both dry unit weight and moisture content. The investigation revealed that inclusion of carpet waste fibers into clay soils prepared at the same dry unit weight can significantly enhance the unconfined compression strength (UCS), reduce postpeak strength loss, and change the failure behavior from brittle to ductile. The results also showed that the relative benefit of fibers to increase the UCS of the clay soils is highly dependent on initial dry unit weight and moisture content of the soil. Failure patterns were gradually transformed from the apparent classical failure for unreinforced soil specimens to barrel-shaped failures for reinforced specimens at 5% fiber content.

Municipalities and recycling and environmental authorities are concerned about the growing amount of carpet waste produced by household, commercial and industrial sectors. It is reported that 500,000 tonnes of carpet waste fibre are plunged into landfills annually in the UK. In the United States of America, around 10 million tonnes of textile waste was generated in 2003. In geotechnical engineering, expansive clay soils are categorised as problematic soils due to their swelling behaviour upon increase in the moisture content. The problematic nature of such soils is intensified with the increase in the plasticity index. This paper presents results of a comprehensive investigation into utilisation of carpet waste fibres in order to improve the swelling characteristics of compacted cohesive soils. Therefore, two different clay soils with markedly different plasticity indices (i.e. 17.0 and 31.5%) were treated with two different types of carpet waste fibre. Waste fibres were added to prepare specimens with fibre content of 1, 3 and 5 % by dry weight of soil. Soil specimens with different dry unit weights and moisture contents were prepared so as to the swelling behaviour of fibre reinforced compacted clays is completely attained under various scenarios. The results indicated that the behaviour of the fibre reinforced soils seems highly dependent on the initial compaction state and secondary on the moisture content. It was found that the swelling pressure drops rapidly as the percentage of fibre increases in samples prepared at the maximum dry unit weight and optimum moisture content. Reducing the dry unit weight, while maintaining constant moisture content or increasing the moisture content at constant dry unit weight was found to reduce the swelling pressure.

The unconfined compression strength test for soils can be used to determine the modulus of subgrade reaction k (sub unc) in the laboratory. It proves more economical and saves time compared with in situ plate loading tests. The modulus obtained from such tests is considerably lower than the modulus obtained from consolidation tests due to the absence of lateral confinement. Stress-subgrade reaction modulus graphs (sigma -k) are presented which show the behavior of k during loading. Some typical k (sub unc) values are given and also Kc values, the slope of the sigma -k curve. Design values of foundations with dimensions B and L can be calculated by using proposed methodology.