Driving Comfort Evaluation for Manhole Covers and Pavement around Manholes

In order to study the driving comfort and influencing factors when vehicles pass over manholes and pavement around manholes on an urban road, the deformation and vibration of the manhole cover were considered, a multidegree of freedom vibration model of the human-vehicle-manhole cover was established, and the variation characteristics of driving acceleration was analyzed. The root mean square of weighted acceleration was taken as the basic index, and driving comfort was evaluated based on ISO 2631-1-1997 standard. After that, 9 influencing factors were analyzed, such as driving speed, subsidence of manhole, manhole cover stiffness, and longitudinal slope. Then, grey correlation entropy analysis was used to evaluate the influencing factors, and the main factors were determined. The results showed that the maximum acceleration was 3.6 m/s2 when a vehicle was passing over a manhole cover under the basic parameters. At the same time, the root mean square of weighted acceleration was 0.975 m/s2 and driving comfort degree was “uncomfortable.” Driving direction and vibration of the manhole cover had little influence on driving comfort, while the remaining influencing factors had significant influence on that. The ranking of key influence factors on driving comfort was longitudinal slope, driving speed, height difference caused by pavement damage, height difference caused by manhole cover subsidence, tire stiffness, manhole stiffness, and tire damping. Therefore, in order to ensure driving comfort and safety, damage to pavement around manholes and manhole cover subsidence should be repaired in a timely manner.

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Damage Evaluation of the Paving around Manholes under Vehicle Dynamic Load

Advances in Materials Science and Engineering ◽

10.1155/2020/6510439 ◽

2020 ◽

Vol 2020 ◽

pp. 1-11

Author(s):

Wenjun Hu ◽

Quanman Zhao ◽

Yao Liu ◽

Zhigang Li ◽

Xianghui Kong

Keyword(s):

Influencing Factors ◽

Static Load ◽

Impact Load ◽

Fourth Power ◽

Height Difference ◽

Driving Speed ◽

Damage Coefficient ◽

Longitudinal Slope ◽

Pavement Damage ◽

The Impact

It is very important for pavement engineers to know which factors are the main reasons for the damage of the paving around manholes. Based on the investigation on the damage of paving around manholes, a vibration model with multidegree of freedom for the vehicle-manhole cover was established and analyzed. After that, the Matlab software was used to obtain the variation law of impact load over time, and the 95% fourth power of the aggregate force was used as the index to evaluate the pavement damage. Finally, many influencing factors on pavement damage were analyzed by the method of grey correlation entropy. The results indicated that the impact load reached the maximum for the first time when the vehicle reached the top of the manhole cover, which was 1.29 times that of the static load, and the pavement damage coefficient was 2.12 times that of the static load. The influencing factors had different degrees of influence on the pavement damage; from large to small, they were change of road longitudinal slope > driving speed > damping of tire > stiffness of tire > height difference from the pavement damage > height difference from the manhole settlement > stiffness of the manhole cover.

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Analysis of influencing factors for rear-end collision on the freeway

Advances in Mechanical Engineering ◽

10.1177/1687814019865079 ◽

2019 ◽

Vol 11 (7) ◽

pp. 168781401986507

Author(s):

Jianfeng Xi ◽

Hongyu Guo ◽

Jian Tian ◽

Lisa Liu ◽

Weifu Sun

Keyword(s):

Influencing Factors ◽

Significant Influence ◽

Traffic Accidents ◽

Influence Factors ◽

Warning System ◽

Analysis Model ◽

Freeway Traffic ◽

Independent Variables ◽

Driving Speed ◽

Fatigue Driving

Rear-end collision accounts for the main type of traffic accidents occurring on the freeway. In order to extract the significant influence factors of rear-end collision on the freeway, this study utilized the data of freeway traffic accidents between 2010 and 2015 in China. First, based on quasi-induced exposure theory, the information of driver, vehicle, and road environment was analyzed. Gender, age, driving age, vehicle safety, load, weather, fatigue, driving speed, road alignment, accident time, and visibility were selected as the important factors that might affect rear-end collision. Second, based on logistic regression model, the influencing factors analysis model of freeway rear-end collision was established. In the regression analysis, the possible important factors selected were taken as the independent variables, and the accident responsibility was taken as the dependent variable. Then, the factors that had significant influence on rear-end collision were selected from candidate independent variables by stepwise regression method. Finally, the specific influence of driving age, load, weather, accident time, visibility, fatigue, and driving speed on rear-end collision occurring on the freeway was discussed. The analysis results were explained according to the odds ratio. The research results of this article can provide guidance for the prevention of rear-end collision on the freeway and theoretical support for the development of freeway early warning system.

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Fig 6. Acceleration along the drill-string. A. Maximum acceleration. B. Root mean square acceleration v1 (protocols.io.ke7cthn)

protocols.io ◽

10.17504/protocols.io.ke7cthn ◽

2017 ◽

Author(s):

Peng Wang ◽

Hongjian Ni ◽

Ruihe Wang

Keyword(s):

Root Mean Square ◽

Drill String ◽

Mean Square ◽

Maximum Acceleration

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Fig 10. Effect of phase difference of shakers on WOB and accelerations. A. Change in weight on bit in the bottom hole with time. B. Maximum acceleration along the drill-string. C. Root mean square acceleration along the drill-string v1 (protocols.io.kfbctin)

protocols.io ◽

10.17504/protocols.io.kfbctin ◽

2017 ◽

Author(s):

Peng Wang ◽

Hongjian Ni ◽

Ruihe Wang

Keyword(s):

Root Mean Square ◽

Phase Difference ◽

Drill String ◽

Mean Square ◽

Maximum Acceleration ◽

Bottom Hole ◽

Weight On Bit

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Fig 9. Effect of installation distance of shakers on weight on bit and accelerations of the drill-string. A. Change of weight on bit in the bottom hole over time. B. Maximum acceleration along the drill-string. C. Root mean square acceleration along the dr v1 (protocols.io.kfactie)

protocols.io ◽

10.17504/protocols.io.kfactie ◽

2017 ◽

Author(s):

Peng Wang ◽

Hongjian Ni ◽

Ruihe Wang

Keyword(s):

Root Mean Square ◽

Drill String ◽

Mean Square ◽

Maximum Acceleration ◽

Bottom Hole ◽

Weight On Bit ◽

Over Time

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Analysis about Main Influence Factors of Vehicle's Fuel Consumption

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.724-725.941 ◽

2013 ◽

Vol 724-725 ◽

pp. 941-945

Author(s):

Bo Peng ◽

Song Lin Ma

Keyword(s):

Environmental Protection ◽

Fuel Consumption ◽

Influence Factors ◽

Reduce Fuel Consumption ◽

Ecological Civilization ◽

Highway Design ◽

Driving Speed ◽

Longitudinal Slope ◽

The Relationship ◽

Main Influence

The construction of ecological civilization is attracting more and more attention. Fuel consumption has greater research value as an important factor in the field of environmental protection and energy saving. Existing analysis about the influence factors of fuel consumption is mostly finished in the 1990s and the beginning of this century, with experiment vehicles and highway at that time, so they may not be suitable for the present. Direct measurement of fuel consumption is finished with actual transportation vehicles in highway and nature state of driving. Analysing the relationship between fuel consumption and speed, longitudinal slope and other main influence factors, put forward measures in highway design, driving speed and other parts to reduce fuel consumption. It is significant for realize energy conservation and environmental protection in traffic.

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