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Preliminary Engineering
Published in Connie Kelly Tang, Lei Zhang, Principles and Practices of Transportation Planning and Engineering, 2021
A guardrail is a fence erected to prevent errant vehicles from crossing to the opposite side of a traveled way or from falling off a traveled way by redirecting vehicles back to their original traveled path. A guardrail system consists of two parts: a rail body and a pair of rail end.
Working at height – hazards and risk control
Published in Phil Hughes, Ed Ferrett, Introduction to Health and Safety in Construction, 2015
The Work at Height Regulations affect approximately 3 million workers for whom working at height is essential to their work. Among other measures, the height of guard rails on scaffolds is increased by 40mm to 950 mm, thus recognising that the average height of workers has increased over the last 40 years. The design of construction projects can also reduce health and safety hazards and accident rates. A study of accident data on falls from height over the 5-year period by the HSE emphasised the importance of building design in the elimination of work at height hazards. For buildings, factories, warehouses, offices, public buildings, retail premises, etc., sufficient dimensions for guard rails or similar barriers will be achieved by complying with the Building Regulations – which require guard rails to be 1100 mm.
Motorway Impact Attenuation Devices: Past, Present and Future
Published in Norman Jones, Tomasz Wierzbicki, Structural Crashworthiness and Failure, 1993
The most commonly employed guardrail system in much of the world consists of a galvanized steel beam shaped in the form of a W (W-beam) and supported on steel or wood posts. Early installations of these W-beam longitudinal barriers were constructed with untreated, blunt ends. This design resulted in many severe accidents, which were sometimes characterized by a piercing of the occupant compartment of the errant vehicle by the sharp end of the W-beam section, as illustrated in Fig. 1. An inexpensive design modification has been extensively employed to reduce the impact severity associated with an untreated, blunt end collision. The end of the W-beam guardrail is twisted through 90∘ and sloped to the ground. 11.12 This eliminated the 'spearing' problem, but vehicles were often launched into the air by the sloped W-beam, resulting in potentially serious rollover accidents.
Bridge deck surface distress evaluation using S-UAS acquired high-spatial resolution aerial imagery
Published in Annals of GIS, 2023
Su Zhang, Susan M. Bogus, Shirley V. Baros, Paul R. H. Neville, Hays A. Barrett, Tyler Eshelman
To characterize the conditions of a bridge deck, four elements are typically inspected, including wearing surfaces, deck joints, guardrails, and structural decks (IDOT 2011). A wearing surface, which is typically constructed of timber, asphalt, or concrete, is a layer placed on the structural deck. A deck joint is designed to allow for traffic between segments of a bridge while facilitating the deck’s transversal, longitudinal, and rotational movement. Guardrails are designed to provide passive protection to vehicles, pedestrians, and bicyclists to keep them inside the road in a secure way. Structural decks, which are typically constructed of concrete, steel, timber, or fibre-reinforced polymer (FRP), comprise the basic plate. It is worth noting that additional elements might be inspected, depending on the specific inspection requirements. Once all elements are inspected by a team of inspectors with different expertise, a report which typically includes textual descriptions of the extent and severity of the observed defects will be prepared. Photos will also be taken by inspectors and included in the report to supplement the inspection results.
Numerical investigation on the dynamic behaviour of derailed railway vehicles protected by guard rail
Published in Vehicle System Dynamics, 2021
Jun Lai, Jingmang Xu, Ping Wang, Jiayin Chen, Jiasheng Fang, Daolin Ma, Rong Chen
Railway infrastructure plays a very important role in land transportation, particularly for developing countries. The safety of railway systems is affected not only by the service performance of the structures (including rails, turnouts, sleepers, subgrades, and bridges), but also by disasters such as earthquakes, typhoons, and mudslides [1,2]. An example of a freight train damaged by derailment is shown in Figure 1. Major consequences of train derailment include the tragic loss of human life as well as damage to the train and secondary damage to surrounding structures, leading to significant economic losses [3,4]. Although guard rails are widely used on bridges, curved portions of track, and earthquake zones, the criteria for effective guard rail design and construction are not clear. Hence the study of protection mechanisms for railway lines is of critical importance.
Effect of guardrail on reducing fatal and severe injuries on freeways: Real-world crash data analysis and performance assessment
Published in Journal of Transportation Safety & Security, 2018
Ning Li, Byungkyu Brian Park, James H. Lambert
The safety benefit of guardrail is reflected in its ability to reduce the severity of a crash when hit as compared with the consequence when guardrail is not in presence. Each RD crash has a discrete outcome of injury severity. It is appropriate to use a discrete choice model to predict the proportion of crashes associated with each of the following crash severity levels: K (fatal), A (severe injury), B (minor injury), C (possible injury), and PDO (Property damage only).