scholarly journals Diagnostics of Bridge Bed Sections and Approaches in Zones of Expansion Joints on Road Bridges

2021 ◽  
Vol 20 (1) ◽  
pp. 10-15
Author(s):  
V. A. Hodyakov ◽  
A. V. Kulan ◽  
E. N. Savina ◽  
I. L. Boiko ◽  
V. A. Grechuhin
Keyword(s):  
Data Collection ◽  
Three Dimensional ◽  
Vibration Response ◽  
Vibration Velocity ◽  
Dynamic Impact ◽  
Vibration Displacement ◽  
Expansion Joints ◽  
Scanning Method ◽  
Natural Operation ◽  
Bridge Structures

The object of the study is durability of expansion joints in bridge structures; the subject of the research is the vibration response of a structure obtained under conditions of natural operation. Diagnostics of the road bridge expansion joints has been carried out in order to identify characteristic dependences  between the value of structure vibration response and types of expansion joint designs during the period of their operation while taking into account the features of the bridge structure. For this purpose, we have tested the methodology for collecting and processing data on the vibration response of the structure under natural conditions of its operation. The paper presents results of data collection on the coverage topology which have been obtained while using three-dimensional scanning method. Data collection on the vibration response of the structure has been carried out by measuring the vibration velocity and deformation of the structure. The data obtained are analyzed. As a result of testing and analysis of the obtained data, the main characteristics have been revealed: the value of base unevenness, the amplitude of vibration velocity and vibration displacement of the structure elements. Two main parameters of the dynamic impact have been assigned, adjusted for the mass of a moving vehicle, which can be used as main parameter for assessing the magnitude of the dynamic impact. A comprehensive method for assessing the dynamic impact on bridge structures has been developed and proposed in the paper, and its use will make it possible to differentiate various designs of expansion joints according to the magnitude of the dynamic impact of vehicles. This, in its turn, will contribute to formulate new recommendations on the use of specific types of expansion joints for various categories of highway, which will increase operational durability of  expansion joints and the structure as a whole.

Artificial Blasting Vibration Response Test and Analysis Based on Cottage Construction of Brick Structure

2013 ◽  
Vol 718-720 ◽  
pp. 1895-1901
Author(s):  
Jing Min Jia
Keyword(s):  
Eastern China ◽  
Housing Affordability ◽  
Vibration Response ◽  
Seismic Exploration ◽  
Housing Construction ◽  
Vibration Velocity ◽  
Dense Area ◽  
Vibration Displacement ◽  
Vibration Direction ◽  
Near Surface

The old oilfield in eastern China has conducted several rounds of seismic exploration. Artificial blasting inevitably layout into town and city building dense area. Quaternary alluvial plains in loose sand, the local large brick structure housing affordability study with artificial explosives directly related to the optimization of blasting parameters. On the basis of a large number of focal blasting venue, housing vibration test data, combined with the near-surface structure and brick structure housing construction characteristics. It focused on analysis different explosive source caused by blasting parameters venues and housing vibration displacement, velocity, acceleration amplitude, frequency characteristic parameters, duration, and vibration direction, summed up the venues and housing vibration response, attenuation relationship, housing construction vibration characteristics and seismic performance. The results show that, depth change of the blasting based on the ground, housing peak attenuation impact, not changes in dose. Vibration velocity, acceleration, displacement exists obvious amplification effect at 130m and 230m.

Test Analysis of Vibration Characteristics on CRTS II Slab Ballastless Track Subgrade of the Beijing-Tianjin Intercity High-Speed Railway

2013 ◽  
Vol 671-674 ◽  
pp. 1263-1266
Author(s):  
Hu Chen ◽  
Kun Lin ◽  
Sheng Bo Fan ◽  
Jian Chen
Keyword(s):  
High Speed ◽  
Horizontal Distribution ◽  
Vibration Response ◽  
Vibration Velocity ◽  
Distribution Law ◽  
Vibration Displacement ◽  
Test Analysis ◽  
Ballastless Track ◽  
Vertical And Horizontal Distribution ◽  
Track Slab

Dynamic response tests were developed on CRTS Ⅱslab ballastless track subgrade of Beijing-Tianjin intercity high-speed railway.The relationship between vibration response and the speed, the vertical and horizontal distribution law of vibration response along lines, the effect of axle load on vibration response were researched.Test results are as follows: The vibration displacement of the extreme value caused by a single axle load is not obvious;Train axle load significantly affects the vibration response;Despite the vertical connection between two track slab, but the end of track slab vibration response is still significantly greater than the middle and the vertical multi-storey line structure vibration response decreases rapidly along the depth;Speed has no significant effect on the vibration displacement, but vibration acceleration and vibration velocity is sensitive to speed.

Measurement of erosion state and refractory lining thickness of blast furnace hearth by using three-dimensional laser scanning method

2020 ◽  
Vol 118 (1) ◽  
pp. 106
Author(s):  
Lei Zhang ◽  
Jianliang Zhang ◽  
Kexin Jiao ◽  
Guoli Jia ◽  
Jian Gong ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Laser Scanning ◽  
Refractory Lining ◽  
Three Dimensional ◽  
3D Laser Scanning ◽  
Scanning Method ◽  
Blast Furnace Production ◽  
Severe Erosion ◽  
Residual Thickness ◽  
Minimum Depth

The three-dimensional (3D) model of erosion state of blast furnace (BF) hearth was obtained by using 3D laser scanning method. The thickness of refractory lining can be measured anywhere and the erosion curves were extracted both in the circumferential and height directions to analyze the erosion characteristics. The results show that the most eroded positions located below 20# tuyere with an elevation of 7700 mm and below 24#–25# tuyere with an elevation of 8100 mm, the residual thickness here is only 295 mm. In the circumferential directions, the serious eroded areas located between every two tapholes while the taphole areas were protected well by the bonding material. In the height directions, the severe erosion areas located between the elevation of 7600 mm to 8200 mm. According to the calculation, the minimum depth to ensure the deadman floats in the hearth is 2581 mm, corresponding to the elevation of 7619 mm. It can be considered that during the blast furnace production process, the deadman has been sinking to the bottom of BF hearth and the erosion areas gradually formed at the root of deadman.

scholarly journals Dynamical behavior of coal shearer under the influence of multiple factors in slant-cutting conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xinwei Yang ◽  
Xianfeng Zou ◽  
Shuai Zhang ◽  
Hongyue Chen ◽  
Yajing Wei ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Fractal Theory ◽  
Dynamical Behavior ◽  
Three Dimensional ◽  
Cutting Conditions ◽  
Vibration Displacement ◽  
Flexible Beams ◽  
Swing Angle ◽  
Wear And Tear ◽  
Working Parameters

AbstractAiming at the problem of severe vibration and abnormal wear and tear of various components in coal shearer under slant-cutting conditions, a non-linear dynamics model with 13 degrees of freedom for a coal shearer under slant-cutting conditions is developed using vibration mechanics and multi-body dynamics theory, and the characteristics of the slide shoes-middle groove contact, the ranging arm-haulage unit connection with gaps and the guidance sliding boots-pin rail multi-surface contact with gaps are described based on three-dimensional fractal theory and Hertz contact theory. Based on Huco's law, the ranging arm and the hydraulic rod are assumed to be flexible beams, the rigidity characteristics of the ranging arm itself, the connection characteristics of the haulage unit and the fuselage are described, a drum correction load with a traction speed correction factor is proposed as the external excitation of the system, and the model is solved and analyzed. The research results show that the change of traction speed has a greater influence on the vibration swing angle and displacement of the front drum, front ranging arm and front walking unit, and the vibration swing angle and displacement of the three increase with the increase of traction speed, while the change of coalface hardness coefficient has less influence on the vibration displacement of the key components of the coal shearer. Under the working parameters of v = 3 m/min and f = 3, the swing angle and displacement of the front ranging arm and front drum fluctuate in the ranges of − 0.4–0.1 rad and – 15–15 mm respectively; the vibration acceleration is – 300–300 rad/s2 and – 200–200 mm/s2 respectively, the main vibration frequencies are 16.63 Hz and 12.14 Hz respectively, and finally the results are verified by experimental methods.

scholarly journals Simulation application of three-dimensional GIS based on full-scenario intelligence in power grid company transmission line planning

2021 ◽  
Vol 2083 (3) ◽  
pp. 032023
Author(s):  
Le Zhang
Keyword(s):  
Data Collection ◽  
Power Grid ◽  
Three Dimensional ◽  
Line Planning ◽  
Mobile Gis ◽  
Time Performance ◽  
Gis Data ◽  
Power Grid Planning ◽  
The Cost ◽  
Grid Planning

Abstract Traditional data collection and review methods in power grid planning have always had the problems of time-consuming, poor real-time performance, and cumbersome processes. The application of mobile GIS solves the problems of data collection and review methods and makes more efficient use of mobile GIS terminal collection. The data of the mobile GIS solve the urgent problems that need to be solved since the popularization and application of mobile GIS. This system implements functions such as storage, transmission, and review based on mobile GIS data, which will greatly improve the efficiency of data collection by mobile terminals and reduce the cost of data collection. Realize the planning simulation of the power grid under the intelligent cycle of the whole scene.

STATIC AND DYNAMIC PERFORMANCE EVALUATION OF A PRE-STRESSED CONCRETE BRIDGE THROUGH FIELD TESTING AND MONITORING

2009 ◽  
Vol 09 (04) ◽  
pp. 711-728 ◽  
Author(s):  
C. S. CAI ◽  
M. ARAUJO ◽  
A. NAIR ◽  
X. SHI
Keyword(s):  
Quantitative Methods ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Field Tests ◽  
Field Measurements ◽  
Field Testing ◽  
Concrete Bridge ◽  
Bridge Structures ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

This paper presents field tests performed on a slab-on-girder pre-stressed concrete bridge. The bridge was tested under static loading, crawling loading, and dynamic loading. A full three-dimensional finite element prediction under both static and dynamic loadings was carried out and the results were compared with the field measurements. While acoustic emission (AE) monitoring of bridge structures is not a new vista, the method has not been fully exploited in bridge monitoring. Though numerous quantitative methods have been proposed, they have not yet developed to be useful for actual field tests of bridges. Therefore, in this study, an attempt was made to use the intensity analysis technique for damage quantification using the AE method.

A theoretical and experimental investigation into the vibration response of a flexible rotor and squeeze-film damper assembly

2001 ◽  
Vol 215 (10) ◽  
pp. 1251-1269 ◽  
Author(s):  
C-C Siew ◽  
M Hill ◽  
R Holmes ◽  
M Brennan
Keyword(s):  
Harmonic Balance ◽  
Three Dimensional ◽  
Harmonic Balance Method ◽  
Vibration Response ◽  
Mode Shapes ◽  
Squeeze Film ◽  
Flexible Rotor ◽  
Linear Vibration ◽  
Squeeze Film Damper ◽  
Good Agreement

This paper presents two efficient methods to calculate the unbalance vibration response of a flexible rotor provided with a squeeze-film damper (SFD) with retainer springs. Both methods are iterative and combine the harmonic balance and receptance approaches. The first method, called the modified iteration method (MIM), is suitable for predicting the three-dimensional mode shapes of a concentric SFD-rotor system. The second method, called the modified harmonic balance method (MHBM), is developed to calculate the non-linear vibration response of a flexible shaft provided with either a concentric or eccentric SFD. The system is also investigated experimentally under different conditions. The predictions computed by these methods are compared with experimental measurements and reasonably good agreement is obtained.

scholarly journals An Energy-Aware Data Transmission Scheme under the Guarantee of Reliability for 3D WSNs

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
J. H. Zhang ◽  
Z. X. Yi ◽  
C. Y. Peng ◽  
Shahid Hussain
Keyword(s):  
Energy Consumption ◽  
Data Collection ◽  
Data Transmission ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Transmission Scheme ◽  
Energy Aware ◽  
Shortest Path Routing ◽  
Transmission Reliability ◽  
Three Dimensional Space

Three-dimensional wireless sensor networks (3D WSNs) play an important role to provide data collection services for Internet of things (IoT) in the real applications. However, many of the existing WSN data collection researches are based on a relatively simple linear or plane network model. The three-dimensional space problems are simplified to two-dimensional plane, which limits the applicability. In this paper, the data collection in 3D WSN is studied. In the three-dimensional space, we firstly analyze the data loads, energy consumption, and end-to-end (E2E) delay of each node when the network is following the shortest path routing. The mathematical analysis of data loads and E2E delay of each node are presented. Based on the analysis of data loads and energy consumption, an energy-ware data transmission scheme is proposed to achieve the trade-off optimization between the E2E delay and network lifetime under the guarantee of the transmission reliability. The key point of the proposed scheme is to make fully use of the unbalanced energy consumption of the 3D WSN. The performance of the proposed scheme is discussed, analyzed, and evaluated. The theoretical analysis and simulation results show that the E2E network delay and energy efficiency can be improved under the constraint of transmission reliability.

scholarly journals Influence of the Acoustic Cover of the Modular Expansion Joint on the Acoustic Climate in the Bridge Structure Surroundings

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2842
Author(s):  
Janusz Bohatkiewicz ◽  
Michał Jukowski ◽  
Maciej Hałucha ◽  
Marcin Dębiński
Keyword(s):  
Sound Level ◽  
Structural Elements ◽  
Expansion Joint ◽  
Expansion Joints ◽  
The Road ◽  
Sound Levels ◽  
Road Surfaces ◽  
Before And After ◽  
Bridge Structures

The noise generated at the interface between the wheels of vehicles and the road surface is well recognized in the literature worldwide. Many publications describe the phenomenon of reducing this kind of impact by silent road surfaces. A specific type of this noise is the sound generated by vehicles passing over the expansion joints of bridge structures. Due to the impulsive nature of this sound, it is very onerous for people living in the close vicinity of bridge structures. The passage of vehicles over expansion joints causes the formation of vibrations that are transmitted to the structural elements of bridge structures, which may cause the formation of the material sounds (especially arduous in the case of bridges with steel elements). An attempt to reduce this impact was made by making a prototype acoustic cover of the expansion joint on the selected bridge. The paper presents the results of research on the “in situ” acoustic effectiveness of this cover. Additionally, the noise was modelled in the object surroundings before and after the cover’s application. The acoustic efficiency of the cover in the whole measured frequency range was 5.3 dBA. In the narrower frequency bands (1/3 octave bands), larger sound level reductions were observed. The maximum sound levels measured under the tested dilatation were less than 10.0 dBA lower than the maximum sound levels measured under the reference dilatation.

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