Browse Topic: Electrical, Electronics, and Avionics
Both concrete guardrails and corrugated beam guardrails have certain wind resistance that can easily hinder wind speed in sections with severe wind-blown sand and snow. This can further cause sand and snow particles to accumulate on the road surface, thereby reducing the friction coefficient of the road surface and having adverse effects on the safety of operating road traffic. The study analyzed the formation mechanism of wind-blown sand and snow, analyzed the functional characteristics of guardrail structure, and explored the SB-level low wind resistance metal beam-post guardrail structure from the perspective of reducing wind resistance area and considering the characteristics of protective vehicles. The main conclusions are as follows: (1) In areas with high wind speed and abundant sand and snow, the roadbed guardrail will have a blocking effect on the wind due to its cross-sectional size, causing wind-blown sand and snow on the road surface. The low wind resistance guardrail can be adopted in key areas, and the metal beam-post guardrail type can be adopted. (2) Considering the types of vehicles protected by SB-level guardrails, the guardrail structure adopts the form of upper and lower beams, with the upper beam mainly protecting large vehicles (buses and trucks) and the lower beam protecting cars. (3) The connection type between beams and posts varies depending on the cross-sectional shape of the tube. Considering the low wind resistance characteristics and structural protection capabilities, circular pipe beams with good wind resistance and square pipe beams with better cross-sectional bending resistance can be used as a beam structure. Circular pipe beams are connected to posts using channel-shaped, while square pipe beams are connected to posts using C-shaped connectors.
The inland waterway system features numerous tributaries and varied channel structures, forming a highly coupled traffic network that results in diverse and complex vessel encounters at river intersections. To investigate the vessel traffic flow conditions at waterway intersections, data were collected at the confluence of the Yangtze River and Xiangjiang River, which represents a typical and strategically important inland navigation hub with intensive traffic activities. Based on high-resolution AIS data, vessel trajectory turning points were identified by using the Douglas–Peucker algorithm, and the topological structure of intersection traffic networks was constructed through OPTICS clustering, thereby extracting turning patterns and navigation paths. Given the complexity of inland vessel traffic flows, the trajectories are classified into four categories according to whether they enter tributaries and their navigation directions. For each trajectory category, representative turning points were identified and treated as network nodes. The node weights were assigned based on the normalized vessel traffic density, which reflects the relative importance of different navigation behaviors. These elements were integrated into a unified topological network that captures both spatial structure and traffic intensity. The topology result reveals the distinct turning patterns and dominant navigation paths associated with vessel traffic flows at inland waterway intersections. The present findings provide a methodological basis for inland waterway planning and maritime safety management.
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