1,720,975 research outputs found
Environmental and occupational risk assessment and management in tunnelling and underground projects
No full textConstruction is one of Europe's biggest industries, providing jobs for nearly 13 million people. This represents nearly 8 % of the working population in Europe (only the public sector and retail employ more). It is also one of the most hazardous industries. More construction workers are killed, injured or suffer health impairments than in any other industry, and one of the most critical section in the construction sector is the underground construction. In particular the effect on workers' health is of serious concern. It is difficult to be precise about the true scale of the health problem, but all studies indicate the problem is huge. Every year many thousands of workers suffer from work related diseases. These include musculoskeletal disorders, noise induced hearing loss, skin diseases, and other diseases as a consequence of exposure to noxious substances. Additionally, the economic costs of poor safety and health are vast. One national study estimates that they typically account for up to 8.5% of a construction project's costs. The creation of underground space has significant impact on quality of life, working conditions, employment and environment. Innovative use of underground space will have a great impact. European Union policies include an upgrading of the Trans European road network (TREN), in order to improve interstate transport. This implies the construction of a significant number of tunnels (approx. 2100 km of tunnels will have to be constructed in Europe by the year 2030). Underground space will be increasingly used to alleviate pressing problems that will confront the European society in the next 20 years: traffic congestion, increasing urbanization (mega cities), lack of space and pollution of air and water. In Italy, the construction of rail and road tunnels through the Alps and the Apennines is very important in terms of connection and moreover, the requirements of transport systems, for civil use spaces and for innovative service networks is one of the reasons for the increase of underground works in urban areas more densely populated. The hydrogeological, geological, operational and environmental criticalities as met in such geological structures can nevertheless require increased care in the aforesaid situations. Projects under construction have further highlighted the importance of tunnels for the elimination of traditional surface, territorial and environmental constraints, but also for the necessary acquisition of consensus through the most comprehensive analysis and management of risks related to the effective fulfilment of such projects, in order both to meet the needs of the end users, and to preserve the dwellers and environmental safety conditions in terms of correct sustainable development. The most important changes in such a point of view occurred since the end of the last century, and suggest the need of a more effective and comprehensive approach to the concept of infrastructure. For this purpose it is nowadays required a horizontal approach, whereby different disciplines (technical, structural, architectural, environmental, financial and occupational safety) can interact and mutually stimulate in order to face the complex issues of underground works project. For these reasons, the designer's role becomes crucial to develop underground projects that respect a sustainable development approach; designer must know innovative and advanced technologies, materials and procedures, aimed at optimizing the economical, environmental and social development. Even the public client, responsible for government priorities and objectives of the intervention, is fundamental for the orientation of the operational choices of designers and builders of infrastructures. In fact, especially in the last decade, a number of guidelines and recommendations were issued by International, European and Italian authorities, the most effective of them based on the introduction of the prevention in the design phase and on a quality based risk management. The design and construction of underground operations require by the Designer and Contractor/s a decision making based on multiple factors (environmental, technological, etc.) that have specific characteristics and particular criticalities, far more than other industrial contexts, since they are often characterized by considerable uncertainty in their definition during the development of the project. In this context the Designer must identify the best option among several available solutions -which have different implications in terms of technical, operational, environmental and financial risks- while the Contractor/s must make a constant check on the preservation of design conditions, in order to control the validity of work and environmental safety requirements. Furthermore, for maintaining the correct safety conditions, it is of primary importance the application of Hazard Identification Techniques referring to different design solutions, and the definition of suitable confidence limits in order to provide the work manager with suitable instruments to constantly evaluate the yard situation and to avoid the overcoming of the aforesaid limits. The PhD research project has therefore to cover the most common criticalities encountered in tunnelling and underground works projects such as: - the presence of pollutants, and in particular carcinogenic minerals, such as, for example, the crystalline silica, which is recognized class A1 carcinogen (carcinogenic certain to humans) by the International Agency for Research on Cancer -IARC- since 1997 (and reaffirmed by the same organization in 2011) and the types of fibrous silicate included in the formal definition of asbestos, which there is no discussion on the ascription to the class A1; - the design and management of the construction yard: the presence of limited working spaces, the high concentration of high power machinery and the use of iterative work cycles, together with reduced time for the excavation, make mandatory the need to plan the interference among concomitant operations in order to prevent accident; - the control of the safety conditions: it is of primary importance the application of Hazard Identification Techniques referring to the choice of suitable confidence limits in order to make available for the work manager the instruments to constantly evaluate the yard situation to avoid the overcoming of the aforesaid limits and referring to the choice of equipment and procedures to minimize accidents at work. Taking into account the best available techniques, the principles of Quality and Prevention through Design approach, the PhD research has also set criteria for the identification and evaluation of the above mentioned criticalities in order to develop an expert system, finalized to make available an integrated system to optimize the economic, environmental and operational safety for the underground works activities in order to proceed rationally to choose the best solutio
The Prevention through Design approach as a key tool in tunnelling operations and muck reuse
No full textPurpose: on the basis of some case histories the problems are here discussed which can arise where a not exhaustive preliminary risk assessment is available, based on a quite detailed knowledge of the characteristics of the material to be excavated. Such problems cover occupational risks deriving from uncorrected selection of the tunnel driving technique and fittings layout, and environmental criticalities associated to unfeasible muck management and destination. The target of the present research work developed with reference to the tunneling operations, is to discuss an effective approach to the safety and health protection of the workers at the construction site, and to the environmental quality conditions in the surrounding areas. The latter should be referred to both the environmental protection, and to the reduction to a minimum of the environmental impact, this involving in particular the possibilities of reuse of the materials resulting from the tunnel driving operations. Methods: the research work is a part of a wide range study carried out by the Department of Environment, Land and Infrastructures Engineering (DIATI) of the Politecnico di Torino for the evaluation of the possibilities of the muck reuse. Nevertheless, this approach is possible only in the case of granted absence of hazards due to the presence in the rock mass to be excavated of noxious materials such asbestos, crystalline silica, etc., since, taken into account that in particular in the case of carcinogens, corrective action following exposure or dispersion is not acceptable, the presence of critical pollutants requires both special preventive actions for the workers health, and the impossibility of any reuse of the muck which could introduce risks for the users (e.g. during mechanical processing involving feeding, crushing, milling, sizing and sorting operations, etc.). Results: the first result is a discussion on the possibilities and techniques of a predictive assessment of the asbestos content in the rock, with special reference to the reliability of the achievable results. The second result is a discussion on the technical possibilities available to minimize the occupational risk where critical rock formations must be excavated. Finally, some considerations are provided on the often underestimated problem of the safety fittings availability, which can prove quite dramatic in the aforesaid critical situations. Conclusions: even if for both economic and environmental reasons the management of the material resulting from tunnel driving operations should be carefully evaluated, and any possible reuse considered, the very first step of such an analysis should be a very careful investigation on the possible content of critical minerals in the rocks to be excavated. In the case, no reuse is possible and a selection of the tunneling techniques and technologies suitable to the minimization of the occupational and environmental risks becomes of primary importance
TUNNELING OPERATIONS, OCCUPATIONAL S&H AND ENVIRONMENTAL PROTECTION: A PREVENTION THROUGH DESIGN APPROACH
Full text linkThe study refers on the main results of a research work that has been carried out by the Safety and Health group of the Department of Environment, Land and Infrastructure engineering (DIATI) at the Politecnico di Torino, with reference to the substantial difference that exists between the case of an established absence of hazards due to the presence of noxious materials such asbestos, crystalline silica, in the rock mass to be excavated and the situations in which these minerals can be present. Since, when carcinogenic substances can be expected, corrective action following exposure or dispersion is clearly unacceptable, the presence of critical pollutants requires special preventive actions for the health of the workers and the muck which can introduce risks for the users (e.g., during mechanical processing involving feeding, crushing, milling, sizing and sorting operations) should not be considered for any reuse
Occupational Safety and Health aspects in mechanized full facetunnel driving: the situation of ante 89/392/ECC TBMs
No full textThe machines for underground operations in EU countries must nowadays comply with the 2006/42/EC Directive on machinery issued by the European Parliament and the Council, a revised version of the former 89/392/EEC Directive. The Italian enforcement of the 2006/42/EC Directive is the law D.Lgs. 17/2010.
With reference to Tunnel Boring Machines - TBMs, an Italian common problem is that nowadays a number of machines produced before the enforcement of the Machinery
Directive 89/392/EEC are, given the considerable costs and resulting long payback periods, still in operation in tunnels.
In this regard, as anticipated by the 89/391/EEC “Framework” Directive, the 89/655/EEC Directive concerning the minimum safety and health requirements for the use of work equipment by workers at work -last revision in 2009/104/EC- should be applied to grant an acceptable safety level. In Italy the situation is nowadays regulated by the enforcement of
the 89/391, the national law D.Lgs. 81/08, specifically in Annex V.
This is not valid if the TBM has not been substantially transformed during the years of service. In this case, in fact, the machine must be subject to the EC marking.
The paper discusses the risk analysis and management approach which should be applied in this particular situation
Occupational safety and health in tunnelling in rocks formations potentially containing asbestos: Good practices for risk assessment and management
Full text linkIn tunnelling operations, Occupational Safety and Health (OS&H) and Environmental Protection of the areas close to the tunnel portal become even more critical in case of rock formations potentially containing asbestos, quartz, radioactive elements, etc. In order to limit the workers' exposure and the environmental impact becomes in these cases of paramount importance to preliminarily analyze and quantify the possible presence of the pollutants in the rock and, if necessary, to implement suitable measures to avoid/minimize their emission from the winning and mucking operations. However, in case of asbestos minerals, to obtain reliable results from the preliminary analysis is a challenging task, due to the complex patterns of occurrence of asbestos within the host rock. Consequently, the definition of special monitoring, alarm and control systems is essential during the tunnel excavation. The paper summarizes the results of a thorough study aimed at defining the most suitable monitoring techniques in uncertain situations and the residual criticalities, essentially due to the delay between the beginning of the pollutant release at the tunnel face and its detection. The final part of the work deals with the possible innovative prevention solutions suitable to minimize the previously mentioned delay and ensure the safety of the workers along the time necessary to stop the activities and evacuate the tunnel, on hold of the activation of a special "asbestos" organizatio
Aspetti di valutazione e gestione del rischio associato alle fasi di generazione e riutilizzo del marino di galleria
Full text linkPredictive assessment of the asbestos content in the Western Italian Alps: an essential tool for an effective approach to Risk Analysis and Management in Tunneling operations and muck reuse
Full text linkThe modern approach to the design and management of tunnel excavation, and muck reuse, can be influenced to a great extent by the possible presence of rock formations containing asbestos minerals. This situation creates problems concerning the protection of theworkers' health and the expectable environmental criticalities, while a drastic re-consideration of the muck destination is necessary. Since, in the case of carcinogens, corrective action following exposure or dispersion is not acceptable, detailed knowledge of the haracteristics of the material to be excavated is all the more essential. Only on this basis it is possible to design the unneling operations in a prevention through design approach, so that the tunnel driving techniques, fittings and technologies, and special equipment and modus operandi, can grant, where necessary, minimized risk conditions, and make a correct decision on whether, how and when these measures must be fully activated, since such an approach involves a remarkable impact on costs and work organization. In the Western Alps a detailed identification and quantification of the asbestos content in rocks is a difficult task, due to the fact that the asbestos in the host rocks, mainly serpentinite, shows a highly variable distribution, typical of ophiolitic belts throughout the world, as it is mostly associated with joints and shear zones. The possibilities of a predictive assessment of the asbestos content in the formations to be excavated are here discussed, with special reference to the reliability of the achievable results
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