scholarly journals Experimental Research on Bearing Characteristics of the Asphalt Pavement Containing Buried Pipeline

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hailiang Xu ◽  
Jining Qin ◽  
Hehuan Ren ◽  
Jindou Sun ◽  
Lian He
Keyword(s):  
Shear Strain ◽  
Experimental Research ◽  
Asphalt Pavement ◽  
Vertical Displacement ◽  
Operating Conditions ◽  
Test Method ◽  
Buried Pipeline ◽  
Buried Pipelines ◽  
Digital Speckle ◽  
Pavement Structure

The bearing characteristics of the asphalt pavement structure are greatly influenced by buried pipelines. Improper treatment of buried pipelines would cause early damage to pavement structure. By the digital speckle correlation method (DSCM), the experimental research on bearing characteristics of the asphalt pavement containing buried pipe was carried out. The mechanical characteristics of the asphalt pavement structure are studied under four different pipeline burial conditions. The vertical displacement and strain values of each layer of the asphalt pavement structure are obtained under four operating conditions. The results showed that (1) the digital speckle observation test method can accurately obtain the displacement and strain values of each layer of asphalt pavement structure containing buried pipeline, and the application effect is good. Compared with the traditional contact strain measurement method, this method is simple and accurate and can provide effective analysis data for experimental research. (2) There exists an interlayer effect of the asphalt pavement structure. The vertical displacement value and the strain value are discontinuities and can suddenly change between two adjacent layers. At the same time, the vertical strain and the shear strain concentration phenomenon appear at the bottom of each layer, especially at the bottom of the upper layer and the subbase layer of asphalt. (3) Affected by the buried pipelines, the vertical displacement value of the asphalt pavement structure reduces, and the tensile and shear strain values of asphalt pavement structure increase. The subbase layer of asphalt is most affected by the buried pipelines, which accelerated the destruction of the asphalt pavement structure.

Mechanics Analysis of Flexible Base Pavement Structure

2014 ◽  
Vol 580-583 ◽  
pp. 632-635
Author(s):  
Li Ya Su
Keyword(s):  
Elastic Modulus ◽  
Tensile Stress ◽  
Asphalt Pavement ◽  
Rapid Development ◽  
Vertical Displacement ◽  
Rigid Base ◽  
Load Factors ◽  
Mechanics Analysis ◽  
Flexible Base ◽  
Pavement Structure

With the rapid development of traffic cause in our country, the operating requirement of driving load factors to pavement structure become higher and higher. The Semi-rigid base asphalt pavement structure exposed some defects and shortcomings, so the study of flexible base asphalt pavement structure is put on the agenda under the circumstances.Based on the research achievements at home and abroad of the existing asphalt pavement structure , choosing different elastic modulus and thickness to calculate and analyze the flexible base by ANSYS, gaining the law and trend of mechanics response (the vertical displacement and tensile stress) about pavement structure for the flexible base pavement of each layer foundation to provide the design reference.

scholarly journals Development of a Full-Depth Wheel Tracking Test for Asphalt Pavement Structure: Methods and Performance Evaluation

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Hui Wang ◽  
Zepeng Fan ◽  
Jiupeng Zhang
Keyword(s):  
Performance Evaluation ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Single Layer ◽  
Test Method ◽  
Shanxi Province ◽  
Wheel Tracking Test ◽  
Pavement Structure ◽  
Pavement Structures ◽  
Wheel Tracking

The rutting performance of asphalt pavement structure relies on the high temperature properties of asphalt mixture as well as the pavement structure and thickness. In order to investigate the influence of the structure and thickness, a full-depth wheel tracking test is developed in this research by improving the conventional wheel tracking test apparatus. The newly proposed test method is capable of varying its load speed and load size, controlling its specimen temperature gradient, and simulating the support conditions of actual asphalt pavement. The full-depth wheel tracking test based rutting performance evaluation of different asphalt pavement structures indicates that it is not reasonable to explain the rutting performance of asphalt pavement structure from the point of view of single-layer asphalt mixture rutting performance. The developed full-depth wheel tracking test can be used to distinguish rutting performance of different asphalt pavement structures, and two of five typical asphalt pavement structures commonly used in Shanxi Province were suggested for use in practical engineering.

scholarly journals Experimental Study on Structural Mechanics of Asphalt Pavement by Digital Speckle Correlation Methods

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Hailiang Xu ◽  
Hehuan Ren ◽  
Jining Qin ◽  
Xu Guo
Keyword(s):  
Stress State ◽  
Asphalt Pavement ◽  
Correlation Method ◽  
Structural Mechanics ◽  
Digital Speckle Correlation Method ◽  
Speckle Correlation ◽  
Correlation Methods ◽  
Digital Speckle ◽  
Pavement Structure ◽  
Digital Speckle Correlation

The experiments on the structural mechanics of asphalt pavement were carried out by the digital speckle correlation method (DSCM). The digital speckle correlation method is used to collect experimental data. The displacement and strain values of each layer of the asphalt pavement structure are analyzed. The research showed that (1) the digital speckle correlation methods could accurately observe the displacement value and the strain value of the pavement structure. (2) The stress state of the pavement structure was greatly influenced by the interlayer effect. The vertical displacement changed suddenly between layers. The concentration phenomenon of the tension-compression strain and the shear strain appeared between layers. (3) The overloading situation seriously worsened the overall stress state of the pavement structure, especially at the bottom of the asphalt top layer and lower layer and at the top of the cement-stabilized crushed stone. The research results are of great significance to the structural design of heavy-duty roads.

Mechanics Analysis of Semi-Rigid Subgrade Pavement Structure

2014 ◽  
Vol 580-583 ◽  
pp. 105-108
Author(s):  
Li Ya Su
Keyword(s):  
Tensile Stress ◽  
Elasticity Modulus ◽  
Asphalt Pavement ◽  
Vertical Displacement ◽  
Pavement Design ◽  
Rigid Base ◽  
Mechanics Analysis ◽  
Pavement Structure ◽  
Early Damage

The semi-rigid base asphalt pavement structure was choose often used to the highway in our country, but the semi-rigid base asphalt pavement early damage almost has become a common phenomenon.In this paper, the rule and trend of mechanics response about pavement structure (the vertical displacement and tensile stress) were analyzed under the semi-rigid base choose different elasticity modulus and thickness by ANSYS for muti-layer foundation of semi-rigid base pavement design to provide reference.

Physical Forces on Buried Pipeline Coatings

2000 ◽  
Author(s):  
Graeme King
Keyword(s):  
Operating Conditions ◽  
Buried Pipeline ◽  
Buried Pipelines ◽  
Design Work ◽  
Physical Forces

Physical forces activated when buried pipelines move relative to the soil can damage coatings. The problem is most common near bends and areas with poor backfill compaction. Most solutions are best implemented early in the design work when pipeline routes, alignments, and operating conditions are being selected. Solutions, in addition to the obvious one of increasing toughness and adhesion of coatings, include increasing radius of bends, avoiding unstable slopes, improving backfill operations, stabilizing operating conditions, and reducing operating pressures and temperatures.

Prediction of Temperature Field of Asphalt Pavement Structure

CICTP 2020 ◽  
2020 ◽  
Author(s):  
Zhizhong Zhao ◽  
Mengchen Li ◽  
Yu Wang ◽  
Wenwen Chen ◽  
Yulong Zhao ◽  
...  
Keyword(s):  
Temperature Field ◽  
Asphalt Pavement ◽  
Pavement Structure

Investigations of Road Wear Caused by Studded Tires

2014 ◽  
Vol 42 (1) ◽  
pp. 2-15
Author(s):  
Johannes Gültlinger ◽  
Frank Gauterin ◽  
Christian Brandau ◽  
Jan Schlittenhard ◽  
Burkhard Wies
Keyword(s):  
Traffic Safety ◽  
Test Bench ◽  
Operating Conditions ◽  
Test Method ◽  
Analytical Models ◽  
The Road ◽  
Driving Speed ◽  
Major Factors ◽  
Tire Friction ◽  
Variable Operating Conditions

ABSTRACT The use of studded tires has been a subject of controversy from the time they came into market. While studded tires contribute to traffic safety under severe winter conditions by increasing tire friction on icy roads, they also cause damage to the road surface when running on bare roads. Consequently, one of the main challenges in studded tire development is to reduce road wear while still ensuring a good grip on ice. Therefore, a research project was initiated to gain understanding about the mechanisms and influencing parameters involved in road wear by studded tires. A test method using the institute's internal drum test bench was developed. Furthermore, mechanisms causing road wear by studded tires were derived from basic analytical models. These mechanisms were used to identify the main parameters influencing road wear by studded tires. Using experimental results obtained with the test method developed, the expected influences were verified. Vehicle driving speed and stud mass were found to be major factors influencing road wear. This can be explained by the stud impact as a dominant mechanism. By means of the test method presented, quantified and comparable data for road wear caused by studded tires under controllable conditions can be obtained. The mechanisms allow predicting the influence of tire construction and variable operating conditions on road wear.

On corrosion properties of ceramic materials for pump friction pairs in lead – bismuth environment

2019 ◽  
pp. 116-122
Author(s):  
V. V. Stepanov ◽  
A. D. Kashtanov ◽  
S. U. Shchutsky ◽  
A. N. Agrinsky ◽  
N. I. Simonov
Keyword(s):  
Composite Materials ◽  
Heat Resistance ◽  
Experimental Research ◽  
Ceramic Materials ◽  
Operating Conditions ◽  
Metallic Materials ◽  
Corrosion Properties ◽  
Liquid Coolant ◽  
Radial Bearing ◽  
Axial Pump

We consider the results of studies on the choice of material of the lower radial bearing of the pump, designed to circulate the coolant lead – bismuth. The circulation of the liquid coolant is provided by a vertical axial pump having a “long” shaft. In this design it is necessary to provide for the lower bearing the lubrication carried out with lead – bismuth coolant. Having analyzed the operating conditions of the axial pump, we decided to carry out the lower bearing in accordance with the scheme of a hydrodynamic sliding bearing. The materials of friction pairs in such a bearing must withstand the stresses arising from the operation of the pump, as well as the aggressive conditions of the coolant. Non-metallic materials – ceramics and carbon-based composite materials – were selected basing on the study of literature data for experimental research on the corrosion and heat resistance in the lead-bismuth environment. 

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