Recommended Circular Curve Radius of Spiral Tunnel in Expressway

CICTP 2020 ◽  
2020 ◽  
Author(s):  
Delong Xiang ◽  
Xiao Li ◽  
Wenchen Gu ◽  
Hao Wei ◽  
Chi Zhang
Keyword(s):  
Curve Radius ◽  
Circular Curve

Research on Interchange Ramp Circular Curve Radius Based on Land-Saving Method

2011 ◽  
Vol 71-78 ◽  
pp. 4109-4114
Author(s):  
Jia Feng Sun ◽  
Ning Yang ◽  
Juan Li ◽  
Jing Qiao ◽  
Jian Gang Qiao
Keyword(s):  
Traffic Safety ◽  
Traffic Engineering ◽  
Large Scale ◽  
Driving Simulator ◽  
Layer Structure ◽  
Land Resource ◽  
Physiological Reaction ◽  
Curve Radius ◽  
Land Saving ◽  
Circular Curve

As an important part of expressway, interchange has space multi-layer structure form and function of stereoscopic transportation steering, which transforms traffic flow, combs and controls traffic. At present the overpass occupies excessive land and large-scale project, which is serious waste of land resources. Under the premise of ensuring road capacity and traffic safety, in order to save land resource, based on Traffic Engineering, Psychology and other theory, the paper used the method of combination of computer simulation and field experiment, that’s through simulation of a driving simulator cabin got the tensity threshold of driver’s psychological and physiological reaction. Field tests were carried on about cars and drivers on the 68 expressway interchanges in Liaoning and Hubei province by using MC5600, dynamic driver heart physiological tester and other equipments. In addition, the paper surveyed the speed of the vehicle on the road and drivers’ psychological and physiological reaction, constructed mathematical model of driver tensity through analyzing feature point velocity and law of drivers’ psychological and physiological reaction, put forward suggested value of land-saving ramp circular curve radius ensuring traffic safety and service level from the point of speed consistency and driver tensity, which would make expressway interchange design meet the concept of economical highway. Therefore, the paper ensures the quality of highway geometric design as well as improves the effectiveness of highway construction and operation.

Analysis of the Minimum Curve Radius of Elastic Bending Turnout of Maglev Transportation

CICTP 2020 ◽  
2020 ◽  
Author(s):  
Zhiwei Zhu ◽  
Guofeng Zeng ◽  
Feng Ye ◽  
Guoqiang Wang ◽  
Yihong Yuan
Keyword(s):  
Elastic Bending ◽  
Curve Radius

Assessment of derailment risk in railway turnouts through quasi-static analysis and dynamic simulation

2021 ◽  
pp. 095440972110240
Author(s):  
Ping Wang ◽  
Jun Lai ◽  
Tao Liao ◽  
Jingmang Xu ◽  
Jian Wang ◽  
...  
Keyword(s):  
Static Analysis ◽  
Dynamic Simulation ◽  
Economic Losses ◽  
Derailment Coefficient ◽  
Straight Line ◽  
Main Track ◽  
Pass Through ◽  
Multi Body ◽  
Yaw Angle ◽  
Curve Radius

Train derailments in railway switches are becoming more and more common, which have caused serious casualties and economic losses. Most previous studies ignored the derailment mechanism when vehicles pass through the turnout. With this consideration, this work aims to research the 3D derailment coefficient limit and passing performance in turnouts through the quasi-static analysis and multi-body dynamic simulation. The proposed derailment criteria have considered the influence of creep force and wheelset yaw angle. Results show that there are two derailing stages in switch panel, which are climbing the switch rail and stock rail, respectively. The 3D derailment coefficient limit at the region of top width 5 mm to 20 mm is much lower than the main track rail, which shows that wheels are more likely to derail in this area. The curve radius before the switch rail is suggested to be set as 350 m. When the curve radius before turnout is 65 m, the length of the straight line between the curve and turnout needs to be larger than 3 m. This work can provide a good understanding of the derailment limit and give guidance to set safety criteria when vehicles pass through the turnout.

Experimental Investigation into Driver Behavior along Curved and Parallel Diverging Terminals of Exit Interchange Ramps

2021 ◽  
pp. 036119812199742
Author(s):  
Alberto Portera ◽  
Marco Bassani
Keyword(s):  
Design Stage ◽  
Lane Change ◽  
Age And Gender ◽  
Traffic Conditions ◽  
Current Design ◽  
The Difference ◽  
Safety Countermeasures ◽  
And Gender ◽  
Set Up ◽  
Curve Radius

Current design manuals provide guidance on how to design exit ramps to facilitate driving operations and minimize the incidence of crashes. They also suggest that interchanges should be built along straight roadway sections. These criteria may prove ineffective in situations where there is no alternative to terminals being located along curved motorway segments. The paper investigates driving behavior along parallel deceleration curved terminals, with attention paid to the difference in impact between terminals having a curvature which is the same sign as the motorway segment (i.e., continue design), and those having an opposite curvature (i.e., reverse design). A driving simulation study was set up to collect longitudinal and transversal driver behavioral data in response to experimental factor variations. Forty-eight drivers were stratified on the basis of age and gender, and asked to drive along three randomly assigned circuits with off-ramps obtained by combining experimental factors such as motorway mainline curve radius (2 values), terminal length (3), curve direction (2), and traffic conditions (2). The motorway radius was found to be significant for drivers’ preferred speed when approaching the terminal. Terminal length and traffic volume do not have a significant impact on either longitudinal or transversal driver outputs. However, the effect of curve direction was found to be significant, notably for reverse terminals which do not compel drivers to select appropriate speeds and lane change positions. This terminal type can give rise to critical driving situations that should be considered at the design stage to facilitate the adoption of appropriate safety countermeasures.

scholarly journals Probability of Roadside Accidents for Curved Sections on Highways

2020 ◽  
Vol 2020 ◽  
pp. 1-18 ◽  
Author(s):  
Guozhu Cheng ◽  
Rui Cheng ◽  
Yulong Pei ◽  
Liang Xu
Keyword(s):  
Risk Factors ◽  
Decision Rules ◽  
Significant Risk ◽  
Vehicle Speed ◽  
Probabilistic Prediction ◽  
Interaction Detection ◽  
Probability Prediction ◽  
Chi Squared ◽  
Longitudinal Slope ◽  
Curve Radius

To predict the probability of roadside accidents for curved sections on highways, we chose eight risk factors that may contribute to the probability of roadside accidents to conduct simulation tests and collected a total of 12,800 data obtained from the PC-crash software. The chi-squared automatic interaction detection (CHAID) decision tree technique was employed to identify significant risk factors and explore the influence of different combinations of significant risk factors on roadside accidents according to the generated decision rules, so as to propose specific improved countermeasures as the reference for the revision of the Design Specification for Highway Alignment (JTG D20-2017) of China. Considering the effects of related interactions among different risk factors on roadside accidents, path analysis was applied to investigate the importance of the significant risk factors. The results showed that the significant risk factors were in decreasing order of importance, vehicle speed, horizontal curve radius, vehicle type, adhesion coefficient, hard shoulder width, and longitudinal slope. The first five important factors were chosen as predictors of the probability of roadside accidents in the Bayesian network analysis to establish the probability prediction model of roadside accidents. Eventually, the thresholds of the various factors for roadside accident blackspot identification were given according to probabilistic prediction results.

scholarly journals Magnetic-Measuring Square in the Measurement of the Circular Curve of Rail Transport Tracks

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 560 ◽  
Author(s):  
Arkadiusz Kampczyk
Keyword(s):  
Operating Mode ◽  
Laser Wavelength ◽  
Rail Transport ◽  
Railway Track ◽  
Actual Condition ◽  
Measuring Device ◽  
Beam Laser ◽  
Magnetic Measuring ◽  
Measurement Results ◽  
Circular Curve

In rail transport, measuring the actual condition of a circular curve of a railway track is a key element of track position monitoring not only during operation but also during final works. Predicting changes in its position in the horizontal plane is one of the most important related scientific issues. This paper presents the results of measurements performed with an innovative measuring device called the Magnetic-Measuring Square (MMS). The aim of the research was to demonstrate the acceptability of using the MMS. Horizontal versines of a rail track curve were measured as three neighboring points on a curve (using the method of lacing/stringlining, also called the three-point or the Hallade method), and the perpendicularity of rail joints and shortenings were measured. The MMS device presented in this article was used to measure versines and differences in rails lengths (rail shortenings in the curve) in the operating mode involving a laser distance meter with a laser beam (laser power P < 1 mW, laser wavelength λ = 635 nm) with a target cross, a camera, and a surveying measuring disk. The measurement results confirmed that it is possible to employ the MMS to monitor the geometry of railway track fragments such as track transition curves and railway track curves in rail transport.

Analysis on the Anti-Glare Plate Setting Distance on Horizontal Curve Sections of Expressway

2014 ◽  
Vol 587-589 ◽  
pp. 2156-2159 ◽  
Author(s):  
Tian Xiao ◽  
Ji Shu Sun ◽  
Can Zhang Jin
Keyword(s):  
Traffic Safety ◽  
Calculation Formula ◽  
Horizontal Curve ◽  
Distance Calculation ◽  
Element Simulation ◽  
Curved Section ◽  
Curve Radius ◽  
The Relationship ◽  
Plate Distance ◽  
Glare Effect

Glare is one of the most important factors threating expressway traffic safety an night. The most commonly way to prevent glaring night is to set anti-glare plate. Different from the straight sections of expressway, the relationship between the front light of vehicles and the distance of anti-glare plate on the horizontal curved section has some-what changed. Through a lot of tests and finite element simulation, the relationship between the distance of anti-glare plate, horizontal curve radius and anti-glare effect were analyzed systematically. Distance calculation formula of anti-glare plate in horizontal curve sections was revised in this paper. The anti-glare plate distance requirement under different expressway alignment design indexes and its calculation formula was proposed. The achievement was beneficial to confirm the anti-glare effect and improve traffic safety. It can provide us with a reference and a supplement of the specification.

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