Design and development of a large shear box for testing working platform material

On large construction projects where deep foundations are to be installed, a working platform is placed across the entire site. This is comprised of a layer of aggregate (often crushed construction waste) usually with a particle size ranging from 120 mm downwards. Deep foundations are installed using heavy and tall drilling rigs and the working platform is thus safety critical to reduce the risk of machinery sinking and/or toppling which would lead to accidents and often serious injury to workers. Currently available design guidance is felt to result in conservative designs and there are many benefits to be gained from a greater understanding of the behaviour of working platform material. The design of these platforms is primarily governed by the angle of friction of the platform material. The measurement of friction angle for geomaterials that have large particle sizes is problematic (due to reasons of scale) and is often addressed by scaling down the material's grading curve prior to testing in small to medium size direct shear apparatus. The work presented here details the design of and the rationale for a large scale direct shear apparatus suitable for testing geomaterials with particle size distributions of the type that would be utilised in working platforms

Centrifuge modelling to determine the influence of pile stiffness on pile capacity

The stiffness of piles relates to their ability to resist deformation in response to an applied force. The modulus of elasticity of an uncracked concrete piles typically varies between 30-40kN/m2. Under axial loading these high stiffness piles transfer the load through the pile to the base. This results in low mobilisation of shaft friction as the stiff pile displaces uniformly and therefore the magnitude of skin friction along the entire length of the pile is small. In addition, base resistance of deep piles is mobilised at very high loads which may exceed the working load of the pile shaft. The adhesion factor, α, for bored piles in London Clay can range between 0.45 and 0.6 suggesting that a significant proportion of the soil strength cannot be mobilised. This low mobilisation of shaft resistance means that the ultimate bearing capacity is much reduced. The research investigated the behaviour of a low stiffness pile under axial load and compared this with a conventional high stiffness pile. The results demonstrated that the low stiffness pile exhibited marginally greater capacity at working load and a noticeably improved capacity at ultimate load

Spatial mobility and large-scale resource extraction: an analysis of community well-being and health in a copper mining area of Zambia

We examine population mobility around a newly-developed large-scale copper mine in Zambia and analyse how socioeconomic and health indicators differed amongst migrants, resettled households, and non-mobile local (e.g. non-migrant/-resettled) populations. Two cross-sectional household surveys in 2015 and 2019 collected quan-titative data on health, socioeconomic indicators, and resettlement and migration status. A wealth index for the pooled sample (N =990 households) was computed using a simplified list of household assets adapted from the Zambia Demographic and Health Survey. Logistic regression models were conducted to assess associations with health outcomes. In-migrants were younger than non-mobile locals (mean age of household head 33.9 vs. 37.7 years), more highly educated (34.3% of household heads completed secondary school vs. 7.3%), had higher employment (43.8% vs. 15.8%), and higher mean wealth (3.6 vs. 3.0). The odds of having a child <5 years diagnosed with malaria (OR: 0.53, 95% CI: 0.40, 0.71) or classified as stunted (OR: 0.66, 95% CI: 0.50, 0.87) were significantly lower for migrants during the construction phase, even after adjusting for family wealth score. Migrant and resettled households had greater wealth and assets even after adjusting for age, education, and employment, suggesting spatial mobility is associated with improved socioeconomic status and disease prevention

Changes in household wealth in communities living in proximity to a large-scale copper mine in Zambia

Large-scale mining can alter the living conditions of surrounding communities in positive and negative ways. A health impact assessment conducted in the context of a newly developed large-scale copper mine in rural Zambia gave us the opportunity to measure changes in health determinants over time. We conducted periodic household surveys at baseline in 2011, during the construction phase in 2015 and during the operational phase in 2019. Data collected included economic indicators that were based on the standardized list of household assets used in the Zambia Demographic and Health Survey, which we subsequently converted into a wealth score using principal component analysis. We compared mean wealth scores in six communities directly impacted by the mine with comparison communities, as well as the rest of the North-Western province of Zambia. A difference-indifferences linear regression model was used to compare changes over time. Mean wealth of the communities near the mine was significantly lower at baseline than that of the North-Western province (? 0.54 points; pvalue< 0.001) in 2011, but surpassed the regional average in 2019 (+1.07 points; p-value <0.001). Mean wealth increased more rapidly in communities directly impacted by mine than in the comparison communities (+0.30 points, p-value <0.001). These results suggest a positive impact on living conditions in communities living near this copper mine. Our findings underscore the potential of the mining sector to contribute to economic development in Zambia

Schistosomiasis and soil-transmitted helminth infections in schoolchildren in north-eastern Democratic Republic of the Congo

BACKGROUND: There is a paucity of epidemiological data pertaining to schistosomiasis and soil-transmitted helminth (STH) infections in the Democratic Republic of the Congo (DRC). METHODS: A cross-sectional survey was carried out in the north-eastern part of DRC enrolling 400 schoolchildren aged 9-14 years. Stool and urine samples were subjected to standard diagnostic methods and examined under a microscope for helminth eggs. RESULTS: Four out of five children were infected with at least one helminth species. Schistosoma mansoni was the predominant species (57.8%). Urine examinations were all negative for S. haematobium. CONCLUSIONS: S. mansoni and STH infections are highly endemic in the surveyed part of the DRC, calling for interventions in school-aged children

Current Global Health Impact Assessment Practice

Health impact assessment (HIA) practice has expanded across the world, since it was established more than two decades ago. This paper presents a snapshot of current global HIA practice based on the findings of an online questionnaire survey. HIA practitioners from all world regions were invited to participate. A total of 122 HIA practitioners from 29 countries completed the survey, following a broad international outreach effort. The large variety in the types of HIAs conducted, and the application of HIA in various fields reported by respondents, demonstrates that HIA practice has evolved over the past two decades. Although differences in the use of HIA were reported across world regions, an overall increasing trend in global HIA practice can be observed. In order to sustain this upward trend, efforts are needed to address the main barriers in the utilisation of HIA. The establishment of new national and international HIA teaching and training offerings seems to be an obvious strategy to pursue along with the strengthening of policies and legal frameworks that specify the circumstances, under which HIA is required, and to what extent

Experience and lessons from health impact assessment guiding prevention and control of HIV/AIDS in a copper mine project, northwestern Zambia

To avoid or mitigate potential project-related adverse health effects, the Trident copper project in Kalumbila, northwestern Zambia, commissioned a health impact assessment. HIV was identified a priority health issue based on the local vulnerability to HIV transmission and experience from other mining projects in Africa. Hence, an HIV/AIDS management plan was developed, including community and workplace interventions, with HIV testing and counselling (HTC) being one of the key components. We present trends in HTC data over a 4-year period.; In 13 communities affected by the Trident project, HTC was implemented from 2012 onwards, using rapid diagnostic tests, accompanied by pre- and post-test counselling through trained personnel. In addition, HTC was initiated in the project workforce in 2013, coinciding with the launch of the mine development. HTC uptake and HIV positivity rates were assessed in the study population and linked to demographic factors using regression analysis.; In total, 11,638 community members and 5564 workers have taken up HTC with an increase over time. The HIV positivity rate in the community was 3.0% in 2012 and 3.4% in 2015, while positivity rate in the workforce was 5.2% in 2013 and 4.3% in 2015. Females showed a significantly higher odds of having a positive test result than males (odds ratio (OR) = 1.96, 95% confidence interval (CI): 1.55-2.50 among women in the community and OR = 2.90, 95% CI: 1.74-4.84 among women in the workforce). HTC users in the 35-49 years age group were most affected by HIV, with an average positivity rate of 6.6% in the community sample and 7.9% in the workforce sample. These study groups had 4.50 and 4.95 higher odds of being positive, respectively, compared to their younger counterparts (15-24 years).; While HTC uptake increased five-fold in the community and almost three-fold in the workplace, the HIV positivity rates were insignificantly higher in 2015 compared to 2012. Our data can be used alongside other surveillance data to track HIV transmission in this specific context. Guided by the health impact assessment, the HIV prevention and control programme was readily adapted to the current setting through the identification of socioeconomic and environmental determinants of health