scholarly journals Characteristics of the Wind Environment above Bridge Deck near the Pylon Zone and Wind Barrier Arrangement Criteria

2020 ◽  
Vol 10 (4) ◽  
pp. 1437 ◽  
Author(s):  
Dalei Wang ◽  
Yiquan Zhang ◽  
Mengjin Sun ◽  
Airong Chen
Keyword(s):  
Wind Speed ◽  
Evaluation Method ◽  
Bridge Deck ◽  
Sudden Change ◽  
Safety Evaluation ◽  
Longitudinal Direction ◽  
Optimal Arrangement ◽  
Wind Environment ◽  
Wind Barrier ◽  
Sutong Bridge

Due to the complex arrangement of structural components in the vicinity of bridge pylon zones, the wind environment above bridge decks is very complicated. A sudden change in wind speed exerts an adverse effect on vehicle control stability. In order to investigate the characteristics of the flow field in the vicinity of the bridge pylon, the wind environment near an inverted Y-shaped pylon is studied by experimental and numerical methods. From the flow visualization and the wind speed measurement in the wind tunnel and the numerical simulation created using Fluent software, specific patterns of the direction and magnitude of wind speed at a range of vehicle height above the bridge deck near the pylon zone were observed along the longitudinal direction. This distribution pattern of the wind environment can effectively guide the wind barrier arrangement near the bridge pylon zone. Combined with the two safety evaluation indicators proposed in this paper, the optimal arrangement scheme of wind barriers in the bridge pylon zone of Sutong Bridge is determined. This paper deepens the understanding of the wind environment near the pylon zone and proposes an evaluation method for the wind environment near the pylon zone, which can serve as the basis for wind barrier arrangement in similar research projects.

Strategy on Improving Lateral Driving Stability of the Automobiles Passing by the Vicinity of A-Shaped Pylon of Zhengxin Yellow River Highway-Railway Bridge in Cross Wind

2011 ◽  
Vol 250-253 ◽  
pp. 1827-1833
Author(s):  
Da Lei Wang ◽  
Ai Rong Chen ◽  
Hui Lin Ai
Keyword(s):  
Wind Speed ◽  
Yellow River ◽  
Driving Safety ◽  
Medium Size ◽  
Railway Bridge ◽  
Complex Flow ◽  
Wind Environment ◽  
Wind Barrier ◽  
Set Up ◽  
Driving Stability

Problem of lateral driving stability of the automobiles passing by the vicinity of pylons of cable-supported bridges in condition of strong cross wind exists obviously because of the alternative wind environment above the deck due to complex flow fluid around the pylon and the deck. Based on numerical wind tunnel technology, the numerical simulation investigation of alternating wind environment above the girder near A-shaped pylon for main span of the steel truss girder cable-stayed bridge of Zhengxin Yellow River Highway-railway Bridge is carried out, considering wind barrier set up on the deck or not. The result shows that the original program has significant effect on wind speed amplification and mutation near the pylon domain in cross wind. Further investigation on wind barrier set up on both sides of the girder section or near the A-shaped pylon along the bridge gives that wind barrier near the A-shaped pylon is useful for reducing wind speed above the leeward deck near the pylon and weakening its mutation. Deeply, taken a medium-size commercial bus as an example, lateral driving stability of the automobiles passing by the leeward lane near A-shaped pylon is discussed through the dynamic response simulation of the vehicle controlled by ideal-driver under cross wind. The results confirms again that the wind barrier near the A-shaped pylon is good for driving safety of vehicles passing by the leeward lanes in vicinity of A-shaped pylon. In all, above work provides technical support for the final implementation of the wind barrier as an engineering measure.

Research on Influences of Wind Screens on Wind-Resistant Capability for Long Span Suspension Bridges

2013 ◽  
Vol 774-776 ◽  
pp. 73-77
Author(s):  
Jia Li Xie ◽  
Cun Ming Ma
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Traffic Safety ◽  
Bridge Deck ◽  
Suspension Bridges ◽  
Wind Environment ◽  
Screen Design ◽  
Long Span ◽  
Tunnel Technique ◽  
Strong Winds

As long span suspension bridges have high towers, large flexibility and low damping, it is a must to consider the wind-resistant stability in bridge designs, especially for sea-crossing bridges where there are always strong winds. To ensure the traffic safety under strong winds, wind screens are often installed on the bridge deck to reduce the wind speed over the roadway. In order to analyze the influence of wind screens on wind-resistant capability and driving security for long span suspension bridges, CFD wind tunnel technique is adopted to analyze the flutter stability, the buffeting displacement and the wind environment of the bridge deck with and without wind screens. According to the analysis, the installation of wind screens could effectively reduce the wind speed over the roadway, but it would also weaken the wind-resistant capability of the bridge. The analysis results could be used as reference for the wind-resistant capability optimization and the wind screen design for long span suspension bridges.

Research on Oil Depot Safety Evaluation Based on Dow Chemical Fire and Explosion Index Assessment Method

2013 ◽  
Vol 748 ◽  
pp. 1256-1261
Author(s):  
Shou Hui He ◽  
Han Hua Zhu ◽  
Shi Dong Fan ◽  
Quan Wen
Keyword(s):  
Production Management ◽  
Evaluation Method ◽  
Risk Index ◽  
Safety Evaluation ◽  
Assessment Method ◽  
Theoretical Ground ◽  
Potential Hazard ◽  
Process Unit ◽  
Safety Production ◽  
Fire And Explosion

At the present time, the Dow Chemical Fire and Explosion Index (F&EI) is a kind of risk index evaluation method that is comprehensively used in evaluating potential hazard, area of exposure, expected losses in case of fire and explosion, etc. As the research object to oil depot storage tank area, this article ultimately confirms establishing appropriate pattern of process unit as well as reasonable safety precautions compensating method, in order to insure the reasonableness of evaluating result, by means of selecting process unit, confirming material factor and compensating safety precautions, using F&EI method. This can provide the basis for theoretical ground in aspect of oil depot development and safety production management.

scholarly journals Study on ecological safety evaluation method for pyrolysis residue of oily sludge

2021 ◽  
Vol 651 (4) ◽  
pp. 042058
Author(s):  
Xuan Sun ◽  
Zhiqiang Guo ◽  
Faguo Zhong ◽  
Zhibin Wu ◽  
Penghui Yang ◽  
...  
Keyword(s):  
Evaluation Method ◽  
Safety Evaluation ◽  
Oily Sludge ◽  
Ecological Safety ◽  
Pyrolysis Residue

Analysis of the Safety Factors of Municipal Road Undercrossing Existing Bridge Based on Fuzzy Analytic Hierarchy Process Methods

2021 ◽  
pp. 036119812110318
Author(s):  
Yonghong Yang ◽  
Yu Chen ◽  
Zude Tang
Keyword(s):  
Safety Assessment ◽  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Safety Evaluation ◽  
Safety Factors ◽  
Analytic Hierarchy ◽  
Road Engineering ◽  
Existing Bridges ◽  
Hierarchy Process ◽  
Engineering Projects

Increasing traffic volume and insufficient road lanes often require municipal roads to be reconstructed and expanded. Where a road passes under a bridge, the reconstruction and expansion project will inevitably have an impact on the bridge. To evaluate the safety impact of road engineering projects on bridges, this paper evaluates the safety of the roads and ancillary facilities of highway bridges involved in municipal road engineering projects. Based on a comprehensive analysis of the safety factors of municipal roads undercrossing existing bridges, a fuzzy comprehensive analytic hierarchy process (AHP) evaluation method for the influence of road construction on the safety of existing bridges is proposed. First, AHP is used to select 11 evaluation factors. Second, the target layer, criterion layer, and index layer of evaluation factors are established, then a safety evaluation factor system is formed. The three-scale AHP model is used to determine the weight of assessment indexes. Third, through the fuzzy comprehensive AHP evaluation model, the fuzzy hierarchical comprehensive evaluation is carried out for the safety assessment index system. Finally, the fuzzy comprehensive evaluation method is applied to the engineering example of a municipal road undercrossing an existing expressway bridge. The comprehensive safety evaluation of the existing bridge reflects the practicability and feasibility of the method. It is expected that, with further development, the method will improve the decision-making process in bridge safety assessment systems.

Reliability and availability evaluation of subsea high integrity pressure protection system using stochastic Petri net

2021 ◽  
pp. 1748006X2110499
Author(s):  
Chuan Wang ◽  
Jun Gou ◽  
Yingcheng Tian ◽  
Hao Jin ◽  
Chao Yu ◽  
...  
Keyword(s):  
Petri Net ◽  
Evaluation Method ◽  
Safety Evaluation ◽  
Diagnostic System ◽  
Test Methods ◽  
Protection System ◽  
Stochastic Petri Net ◽  
Practical Engineering ◽  
Common Cause Failures ◽  
High Integrity

In this paper, a safety evaluation method of subsea High Integrity Pressure Protection System (HIPPS) based on a generalized stochastic Petri net model is proposed. Different test methods were used to detect different types of failures and to analyze the reliability of HIPPS components under the influence of common cause failures and incomplete repair. The reliability curve of a diagnostic system consisting of a transmitter system and a logic system under the influence of uncertainty over time is analyzed. The safety of HIPPS with diverse test methods were quantitatively analyzed. The results show a significant improvement in the performance of the system after testing and maintenance. Both partial-stroke testing and increased partial-stroke test coverage can be used to increase the HIPPS performance compared to traditional methods. The analysis of the Partial stroke test (PST) strategy can afford a academic basis for the selection of PST frequency and Functional test (FT) interval in practical engineering.

Research to Health Diagnose Model of Gate and Hoist Machinery Based on AHP

2011 ◽  
Vol 287-290 ◽  
pp. 3036-3042 ◽  
Author(s):  
Guang Ming Yang ◽  
Wen Bin Jia
Keyword(s):  
Evaluation Method ◽  
Safety Evaluation ◽  
Metal Structure ◽  
Weight Coefficient ◽  
Diagnostic Model ◽  
Ahp Method ◽  
Safety Level ◽  
Comprehensive Health ◽  
Expert Evaluation Method ◽  
Health Diagnosis

Safety evaluation index is a fundamental and key element in composing hydraulic metal structure healthy diagnostic model, however,the determination of weighting of Indexes is closely related to the reasonability and reliability of the whole evaluation result.Based on the safety level, importance and expertise of the main factors on hydraulic metal structure,we also combine integration of AHP method of nine marks and expert evaluation method to determine the weight coefficient of each index, the comprehensive health diagnosis of gates and hoists based on AHP method are first constructed in line with scientific and rational principles .And we use the model to achieve the specific project safety evaluation of hydraulic metal structures, also comparing it with the traditional comparative analysis, proving the comprehensive health diagnosis based on AHP model to be a more scientific, reasonable and reliable one.

Analysis for the Effect of Wind Barrier on Reducing Wind Velocity across a Bridge

2012 ◽  
Vol 256-259 ◽  
pp. 2739-2742
Author(s):  
Ji Hong Bi ◽  
Peng Lu ◽  
Jian Wang ◽  
Chun Bao
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Speed ◽  
Wind Velocity ◽  
Efficient Design ◽  
Wind Barrier ◽  
Strong Winds

A bridge, which is located in the route of typhoon, is considered how to assure normal traffic use against strong winds. As one of the measures, wind barrier is proposed to be set on both sides of the bridge section for reducing wind velocity across it. In this study, an analysis by using CFX, a computational fluid dynamics program, is carried out to investigate the effects of wind barrier. The speed of wind is assumed as 60m/s. To find out an efficient design of the boards, different porosity ratios(r) of the boards is assumed for comparison. The result shows that wind barrier could reduce the wind speed across the bridge effectively.

Sign in / Sign up

Export Citation Format

Share Document