scholarly journals Detection and analysis of deck cracks in a long span empirically designed bridge deck through embedded sensory systems

2006 ◽  
Author(s):  
Mourad Y. Riad
Keyword(s):  
Bridge Deck ◽  
Sensory Systems ◽  
Long Span ◽  
Deck Cracks

Control of Vibrations due to Moving Loads on Suspension Bridges

2006 ◽  
Vol 11 (3) ◽  
pp. 293-318 ◽  
Author(s):  
M. Zribi ◽  
N. B. Almutairi ◽  
M. Abdel-Rohman
Keyword(s):  
Bridge Deck ◽  
Suspension Bridge ◽  
Lyapunov Theory ◽  
Dynamic Responses ◽  
Suspension Bridges ◽  
Control Force ◽  
Moving Loads ◽  
Hydraulic Actuator ◽  
Long Span ◽  
Suspended Cables

The flexibility and low damping of the long span suspended cables in suspension bridges makes them prone to vibrations due to wind and moving loads which affect the dynamic responses of the suspended cables and the bridge deck. This paper investigates the control of vibrations of a suspension bridge due to a vertical load moving on the bridge deck with a constant speed. A vertical cable between the bridge deck and the suspended cables is used to install a hydraulic actuator able to generate an active control force on the bridge deck. Two control schemes are proposed to generate the control force needed to reduce the vertical vibrations in the suspended cables and in the bridge deck. The proposed controllers, whose design is based on Lyapunov theory, guarantee the asymptotic stability of the system. The MATLAB software is used to simulate the performance of the controlled system. The simulation results indicate that the proposed controllers work well. In addition, the performance of the system with the proposed controllers is compared to the performance of the system controlled with a velocity feedback controller.

Performance Evaluation of a Novel High Durability Epoxy Asphalt Concrete for Bridge Deck Pavements

2014 ◽  
Vol 488-489 ◽  
pp. 550-553
Author(s):  
Xing Song Cao ◽  
Dong Wei Cao ◽  
Shi Xiong Liu ◽  
Xio Qiang Yang ◽  
Lin Lan
Keyword(s):  
Asphalt Concrete ◽  
Bridge Deck ◽  
Asphalt Binder ◽  
Laboratory Evaluation ◽  
Suitable Material ◽  
Long Span ◽  
Epoxy Asphalt ◽  
High Durability ◽  
Specimen Test ◽  
Epoxy Asphalt Concrete

A novel high durability epoxy asphalt concrete for bridge deck pavements is introduced in this paper, including the manufacturing process of epoxy asphalt binder and laboratory evaluation for this material. Various laboratory tests were conducted to evaluate the pavement performance of the materials, such as fatigue test, wheel tracking test, moisture susceptibility test and thermal stress restrained specimen test. Test results show that epoxy asphalt concrete has 20137 cycles/mm dynamic stability at 70°C, and-28.4 °C fracture temperature. The fatigue equations of epoxy asphalt concrete at different temperatures were obtained. Findings from the research indicate that the epoxy asphalt concrete is a suitable material for the pavement of long-span steel bridges in China due to its profound performance.

scholarly journals Deep Learning Based Vehicle Detection and Classification Methodology Using Strain Sensors under Bridge Deck

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5051
Author(s):  
Rujin Ma ◽  
Zhen Zhang ◽  
Yiqing Dong ◽  
Yue Pan
Keyword(s):  
Neural Network ◽  
Bridge Deck ◽  
Vehicle Detection ◽  
Traffic Monitoring ◽  
Transportation Systems ◽  
Strain Sensors ◽  
Long Span ◽  
Long Span Bridge ◽  
Pavement Evaluation ◽  
Close Range

Vehicle detection and classification have become important tasks for traffic monitoring, transportation management and pavement evaluation. Nowadays there are sensors to detect and classify the vehicles on road. However, on one hand, most sensors rely on direct contact measurement to detect the vehicles, which have to interrupt the traffic. On the other hand, complex road scenes produce much noise to consider when to process the signals. In this paper, a data-driven methodology for the detection and classification of vehicles using strain data is proposed. The sensors are well arranged under the bridge deck without traffic interruption. Next, a cascade pre-processing method is applied for vehicle detection to eliminate in-situ noise. Then, a neural network model is trained to identify the close-range following vehicles and separate them by Non-Maximum Suppression. Finally, a deep convolutional neural network is designed and trained to identify the vehicle types based on the axle group. The methodology was applied in a long-span bridge. Three strain sensors were installed beneath the bridge deck for a week. High robustness and accuracy were obtained by these algorithms. The methodology proposed in this paper is an adaptive and promising method for vehicle detection and classification under complex noise. It would serve as a supplement to current transportation systems and provide reliable data for management and decision-making.

Research on the Wind Tunnel Force Balance Tests of Long-Span Closed Coal Trestle

2013 ◽  
Vol 477-478 ◽  
pp. 797-802
Author(s):  
Shu Liang Wang ◽  
Shu Guo Liang ◽  
Liang Hao Zou ◽  
Xiang Yang Zhou
Keyword(s):  
Wind Tunnel ◽  
Bridge Deck ◽  
Force Balance ◽  
Mean Values ◽  
Long Span ◽  
Balance Tests ◽  
Section Model ◽  
Base Forces ◽  
Experimental Values ◽  
High Flexibility

Structures with long span and high flexibility are very sensitive to the wind forces, so it is necessary to study on the wind effects on such structures. In this paper, based on section model wind tunnel high-frequency force balance tests, two horizontal base bending moments and shear forces of the typical supporting columns as well trestle bridge deck of the closed coal trestle under different wind directions were measured. The shape coefficients and their variations with the wind directions of the typical supporting columns as well trestle bridge deck were calculated then analyzed by the mean values of base forces. The experimental values of the shape coefficients were compared with those in the Chinese Load Code, the results shown that both were in good agreement, which verified the reliability of the test, which also illustrated that wind-resistant design of the coal trestle in accordance with the Code was reasonable. Based on analysis of the variances of base forces between overall model with and without surrounding buildings, influences of surroundings buildings were studied. Interference factors were proposed which provided the basis for the base forces checking and wind-resistant design of the long-span closed coal trestle structures.

scholarly journals Steady-Suction-Based Flow Control of Flutter of Long-Span Bridge

2020 ◽  
Vol 10 (4) ◽  
pp. 1372
Author(s):  
Jian Zhan ◽  
Hongfu Zhang ◽  
Zhiwen Liu ◽  
Huan Liu ◽  
Dabo Xin ◽  
...  
Keyword(s):  
Flow Control ◽  
Bridge Deck ◽  
Control Method ◽  
Control Device ◽  
Maximal Increase ◽  
Long Span ◽  
Suction Control ◽  
Long Span Bridge ◽  
Bridge Model ◽  
Section Model

The present wind tunnel study focuses on the effects of the steady-suction-based flow control method on the flutter performance of a 2DOF bridge deck section model. The suction applied to the bridge model was released from slots located at the girder bottom. The suction rates of all slots along the span were equal and constant. A series of test cases with different combinations of suction slot positions, suction intervals, and suction rates were studied in detail for the bridge deck model. The experimental results showed that the steady-suction-based flow control method could improve the flutter characteristics of the bridge deck with a maximal increase in the critical flutter speed of up to 10.5%. In addition, the flutter derivatives (FDs) of the bridge deck with or without control were compared to investigate the fundamental mechanisms of the steady-suction-based control method. According to the results, installing a suction control device helps to strengthen aerodynamic damping, which is the primary cause for enhanced flutter performance of bridge decks.

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