scholarly journals Temporary Cable Force Monitoring Techniques During Bridge Construction-phase. The Tajo River Viaduct Experience

2021 ◽  
Author(s):  
Álvaro Gaute-Alonso ◽  
David Garcia-Sanchez ◽  
Carlos Alonso Cobo ◽  
Iñigo Calderon-Uriszar-Aldaca
Keyword(s):  
Strain Gauges ◽  
Construction Process ◽  
Vibrating Wire ◽  
Monitoring Techniques ◽  
Advantages And Disadvantages ◽  
Load Cells ◽  
Cable Force ◽  
Force Monitoring ◽  
Process Context ◽  
Cable Forces

Abstract This article addresses the comparative analysis of current techniques for monitoring cable forces. Additionally, the experience of three cable force different monitoring techniques for strain control in bridge cables during the construction phase is included: a) installing load cells on the active anchorages of the cables, b) installing unidirectional strain gauges, and c) assessing the stress on cables by applying the vibrating wire technique through the installation of accelerometers. The main advantages and disadvantages of each technique analyzed are highlighted in the construction process context of the Tajo Viaduct, one of the most singular viaducts recently built in Spain.

Optimal sensor placement for cable force monitoring based on multioutput support vector regression model

2018 ◽  
Vol 21 (15) ◽  
pp. 2259-2269 ◽  
Author(s):  
Shunlong Li ◽  
Huiming Yin ◽  
Zhonglong Li ◽  
Wencheng Xu ◽  
Yao Jin ◽  
...  
Keyword(s):  
Support Vector Regression ◽  
Regression Models ◽  
Sensor Placement ◽  
Prediction Performance ◽  
Support Vector ◽  
Optimal Sensor Placement ◽  
Cable Force ◽  
Force Monitoring ◽  
Placement Algorithm ◽  
Cable Forces

Cable force monitoring is an essential and critical part of structural health monitoring for cable-supported bridges. The quality of obtained information depends considerably on the number and location of limited sensors. The purpose of this article is to provide a method for optimal sensor placement for cable force monitoring in cable-supported bridges. Based on the spatial correlation between neighbouring or symmetrical cable forces, the structural information of non-monitored cables can be predicted by multioutput support vector regression models, established between monitored (input) and the non-monitored (output) cable forces. The number and placement of cable force sensors have significant influence on prediction performance of established multioutput support vector regression models. The proposed optimal sensor configuration is to select multioutput support vector regression models with minimum prediction error from all possible sensor locations. In this study, information entropy is employed to measure the prediction performance of different sensor configurations and formulate the objective function, optimised by three computationally effective algorithms: forward sequential sensor placement algorithm, backward sequential sensor placement algorithm and genetic algorithm. The application of proposed method to Nanjing No. 3 Yangtze River Bridge confirmed the efficiency, accuracy and effectiveness of the proposed method.

Improvements in Data Acquisition for Propulsion Shaft Alignment

2015 ◽  
Author(s):  
W. David Joiner ◽  
Charles J. Cook
Keyword(s):  
Data Acquisition ◽  
Strain Gage ◽  
Strain Gages ◽  
Construction Process ◽  
Crucial Step ◽  
Ship Construction ◽  
Shaft Line ◽  
Load Cells ◽  
Shaft Alignment

Propulsion shaft alignment is a necessary and crucial step in the ship construction process, with manning and schedule constraints requiring accurate results as efficiently as possible. There are two methods for measuring the bearing loading along the shaft line: strain gages and load cells. The legacy method for using strain gages required a lot of man power and the legacy method for using load cells was dependent on the quality of machinist made available. Strain gages are the transducers of choice for measurement; however the data acquisition, especially for ships with long shafting systems, can require many strain gage positions and personnel to conduct tests. Load cells are used to validate the accuracy of the strain gage method and to calculate the shaft runout at each bearing location.

Evaluation of Negative Skin Friction on Bridge Abutment Piles

2021 ◽  
Vol 15 (2) ◽  
Author(s):  
Osama Drbe
Keyword(s):  
Skin Friction ◽  
Pore Water Pressure ◽  
Design Method ◽  
Water Pressure ◽  
Strain Gauges ◽  
Total Stress ◽  
Vibrating Wire ◽  
Negative Skin Friction ◽  
Drag Forces ◽  
Wire Strain

Piles are used to transfer loads of structures to deeper and stronger soil layers through skin friction and/or end bearing. Surcharge loads, site grading, or dewatering may induce downward movement of soil adjacent to piles installed in a compressible medium. This movement creates negative skin friction stresses acting downward at the pile-soil interface, which applies additional loads “drag forces” to the pile causing a maximum axial load in the pile shaft at the “neutral plane”. To evaluate the development of drag forces, a comprehensive field monitoring program was conducted over four years for three instrumented abutment H-piles as part of a three-span bridge project. The soil settlement and changes in pore water pressure in the soil adjacent to the piles due to the construction of an approach embankment were monitored using multiple-point extensometers and vibrating wire piezometers. The piles’ elastic settlement and strains were measured using single-point extensometers and vibrating wire strain gauges. The field measurements are presented and discussed in terms of responses time histories and load distribution along one pile shaft. In addition, the calculated forces from vibrating wire strain gauges are compared with the unified design method prediction considering the total stress method (α-method) for cohesive soils. The results show that the maximum drag force was developed after the complete dissipation of excess pore water pressure and that the location of neutral plane varied during the embankment construction stages. Employing the total stress method in the unified design method provided a reasonable prediction of the drag force and the neutral plane’s location.

Application of optical fiber Bragg grating strain gauge to cable force monitoring of FAST

2015 ◽  
Vol 23 (4) ◽  
pp. 919-925 ◽  
Author(s):  
孙晓 SUN Xiao ◽  
王启明 WANG Qi-ming ◽  
朱明 ZHU Ming ◽  
吴明长 WU Ming-chang
Keyword(s):  
Optical Fiber ◽  
Fiber Bragg Grating ◽  
Strain Gauge ◽  
Bragg Grating ◽  
Cable Force ◽  
Force Monitoring ◽  
Optical Fiber Bragg Grating

scholarly journals Temperature and Strain Correlation of Bridge Parallel Structure Based on Vibrating Wire Strain Sensor

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 658 ◽  
Author(s):  
Lu Peng ◽  
Genqiang Jing ◽  
Zhu Luo ◽  
Xin Yuan ◽  
Yixu Wang ◽  
...  
Keyword(s):  
Sensor Data ◽  
Parallel Structure ◽  
Strain Gauges ◽  
Final Conclusion ◽  
Vibrating Wire ◽  
Traceability System ◽  
Wire Strain ◽  
Time Work ◽  
Long Time ◽  
Dynamic Acquisition

Deformation is a ubiquitous phenomenon in nature. This process usually refers to the change in shape, size, and position of an object in the time and spatial domain under various loads. Under normal circumstances, during engineering construction, technicians are generally required to monitor the safe operation of structural facilities in the transportation field and the health of bridge, because monitoring in the engineering process plays an important role in construction safety. Considering the reliability risk of sensors after a long-time work period, such as signal drift, accurate measurement of strain gauges is inseparable from the value traceability system of high-precision strain gauges. In this study, two vibrating wire strain gauges with the same working principle were measured using the parallel method at similar positions. First, based on the principle of time series, the experiment used high-frequency dynamic acquisition to measure the thermometer strain of two vibrating wire strain gauges. Second, this experiment analyzed the correlation between strain and temperature measured separately. Under the condition of different prestress, this experiment studied the influencing relationship of temperature corresponding variable. In this experiment, the measurement repetitiveness was analyzed using the meteorology knowledge of single sensor data, focused on researching the influence of temperature and prestress effect on sensors by analyzing differences of their measurement results in a specified situation. Then, the reliability and stability of dynamic vibrating wire strain gauge were verified in the experiment. The final conclusion of the experiment is the actual engineering in the later stage. Onsite online meteorology in the application provides support.

Application of Quadratic Programming Method to Cable Force Calculation of Cable Erection Arch Bridge

2014 ◽  
Vol 587-589 ◽  
pp. 1364-1369
Author(s):  
Cheng Wu ◽  
Jin Yu Liu ◽  
Shui Xing Zhou
Keyword(s):  
Quadratic Programming ◽  
High Precision ◽  
Steel Tube ◽  
Influence Matrix ◽  
Calculation Process ◽  
Cable Force ◽  
Quadratic Programming Method ◽  
Cable Forces ◽  
Force Calculation ◽  
Number Of Iterations

Taking the bare arch deformation under gravity as target alignment, the influence matrix that associates the cable forces with segment deformation is obtained via ANSYS program, and the cable force is quickly calculated by MATLAB quadratic programming toolbox. It is illustrated with an example of Guizhou Zong-xi River Bridge, which is a 360-meter concrete filled steel tube bridge in construction, and the calculation process is given. The results show that, this new method has the advantages of high precision and less number of iterations.

Calculation of Cable Force for Long-Span Rib Arch Bridge Construction under Seasonal Ambient Temperature

2011 ◽  
Vol 378-379 ◽  
pp. 341-344
Author(s):  
Wei Feng Tian ◽  
Shui Xing Zhou ◽  
Ayad Thabet Saeed Alghabsha
Keyword(s):  
Ambient Temperature ◽  
Control Method ◽  
Difficult Problem ◽  
State Control ◽  
Optimization Analysis ◽  
Arch Bridge ◽  
Long Span ◽  
Unstressed State ◽  
Cable Force ◽  
Cable Forces

Calculation of cable force under seasonal ambient temperature is the key and difficult problem in the construction of long-span rib arch bridge. It affects the final cable forces and deformations of arch rib after arch closure. Unstressed state control method is introduced in the construction of Daning River Bridge; unstressed qualities of ribs and unstressed length of cables can be obtained by optimization analysis of the maximum cantilever state in construction. According to unstressed state control method, the cable forces of each segment were calculated using the forward-iteration method. These results offer the basis for construction control, and guarantee the arch rib line and cable forces to meet the design requirements, and an arch closure with high precision.

COMPARISION OF ALTERNATIVE CONSTRUCTION DISPUTE RESOLUTION MEASURES

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Ulrike Quapp ◽  
Klaus Holschemacher
Keyword(s):  
Dispute Resolution ◽  
Construction Industry ◽  
Alternative Dispute Resolution ◽  
Construction Projects ◽  
Legal Aspects ◽  
Construction Process ◽  
Legal Proceedings ◽  
Advantages And Disadvantages ◽  
Industry Practice

Construction projects often are particularly susceptible to conflicts due to their long-term character and complexity. In Germany, courts must deal with around 100,000 construction dispute litigations per year. Alternative Dispute Resolution (ADR) can be an alternative to expensive as well as time-consuming litigation and can help to relieve the judicial system. Furthermore, ADR may contribute to the satisfying settlement of a dispute between parties involved in the construction process and thus help to reach construction projects’ completion on time and within budget. Often, ADR mechanisms such as adjudication, mediation, and conciliation will be used. The paper analyzes the development of ADR in Germany in conjunction with European legal aspects. With special reference to the construction industry practice in Germany, various ADR measures and their advantages and disadvantages, as well as the current situation, will be explained. The authors conclude that, although ADR in Germany has experienced an upswing since the 1990s, it is used only to a small extent for settling disputes in construction projects. An increased knowledge about the advantages and disadvantages of different ADR measures in the construction industry would lead to more frequent uses of ADR. That, and a clever and detailed contract design, which helps to avoid conflicts basing on unclear contract contents, could save money and relieve the courts from time-consuming legal proceedings.

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