Factors Influencing the Implementation of Site Waste Management Plans on UK Projects of all sizes

The purpose of this research is to identify and assess the opportunities and challenges of implementing a Site Waste Management Plan (SWMP) on projects irrespective of size. In the UK, construction and demolition waste accounts for a third of all UK waste. There are a number of factors that influence the implementation of SWMPs. In order to identify and analyse these factors, 4 unstructured interviews were carried out and a sample of 56 participants completed a questionnaire survey. The scope of the study was limited to UK
construction industry professionals. The analysis revealed that more needs to be done if the industry is to meet government targets of reduction in construction related waste going to landfill. In addition, although SWMP may not yet be legally required on all construction projects, clients and contractors need to realise
the benefits to cut costs and implement best practice by adopting a SWMP. The benefits of implementing a SWMP will not only help to achieve this but also gain significant cost savings on projects and is also extremely beneficial to the environment. This study presents evidence that contractors need to do more to reduce waste and draws a clear link between waste reduction and the implementation of SWMPs. The findings are useful in the ongoing efforts to encourage the industry to find smarter, more efficient and less
damaging ways to operate

Validation of non‑stationary precipitation series for site‑specific impact assessment: comparison of two statistical downscaling techniques

Statistical downscaling (SD) methods have become a popular, low-cost and accessible means of bridging the gap between the coarse spatial resolution at which climate models output climate scenarios and the finer spatial scale at which impact modellers require these scenarios, with various different SD techniques used for a wide range of applications across the world. This paper compares the Generator for Point Climate Change (GPCC) model and the Statistical DownScaling Model (SDSM)—two contrasting SD methods—in terms of their ability to generate precipitation series under non-stationary conditions across ten contrasting global climates. The mean, maximum and a selection of distribution statistics as well as the cumulative frequencies of dry and wet spells for four different temporal resolutions were compared between the models and the observed series for a validation period. Results indicate that both methods can generate daily precipitation series that generally closely mirror observed series for a wide range of non-stationary climates. However, GPCC tends to overestimate higher precipitation amounts, whilst SDSM tends to underestimate these. This infers that GPCC is more likely to overestimate the effects of precipitation on a given impact sector, whilst SDSM is likely to underestimate the effects. GPCC performs better than SDSM in reproducing wet and dry day frequency, which is a key advantage for many impact sectors. Overall, the mixed performance of the two methods illustrates the importance of users performing a thorough validation in order to determine the influence of simulated precipitation on their chosen impact sector.

Barriers to Subcontracted Labor Productivity in Urban Development Projects: An On-site Project Management Perspective

Considering the confined and complex nature of urban construction projects, labor productivity is one of the key factors attributing to project success. With the proliferation of sub-contracted labor, there is a necessity to consider the ramifications of this practice to the sector. This research aims to outline how project managers can optimise productivity levels of sub-contracted labor in urban construction projects, by addressing the barriers that most restrict these efficiency levels. A qualitative research approach is employed, incorporating semi-structured interviews based on three case studies from an urban context. The results are scrutinised using mind mapping software and accompanying analytical techniques. The findings from this research indicate that the effective on-site management of sub-contracted labor has a significant impact on the degree of success of an urban development project. The two core barriers to sub-contracted labor productivity are; 1) ineffective supervision of sub-contracted labor, and 2) lack of skilled sub-contracted labor. The implication of this research is that on-site project management play an integral role in the level of productivity achieved by sub-contracted labor in urban development projects. Therefore, on-site management situated in urban, confined construction sites, are encouraged to take heed of the findings herein and address the barriers documented. The value of this research is obtained through consideration of the critical factors; construction management professionals can mitigate such barriers, in order to optimise subcontracted labor productivity on-site.