Measurement of Strut Loads by Means of Vibrating-Wire Strain Gages

2009 ◽  
pp. 58-58-20 ◽  
Author(s):  
TD O'Rourke ◽  
EJ Cording
Keyword(s):  
Strain Gages ◽  
Vibrating Wire ◽  
Wire Strain

Developing Large Slab Airport Runways for the Next Century

2019 ◽  
Vol 2673 (6) ◽  
pp. 524-535
Author(s):  
Stephen J. Roswurm ◽  
Chris Ramseyer
Keyword(s):  
Drying Shrinkage ◽  
Early Age ◽  
Strain Gages ◽  
Vibrating Wire ◽  
Type K ◽  
Wire Strain ◽  
Load Cells ◽  
Mineral Additive ◽  
Shrinkage Compensation ◽  
Airport Runway

The purpose of this research was to determine whether shrinkage-compensating concrete (SCC) made with Type K cement can create durable airport runways with fewer joints and reduced maintenance costs. The primary criterion examined was the ability of SCC to offset the effects of early-age drying shrinkage when the concrete is acted upon by external restraint. The interaction of restraint with SCC is important because restraint resists the expansive behavior that provides shrinkage compensation. Four sets of experiments were conducted, with increasing levels of Type K expansive mineral additive in each set. A set of test specimens consisted of four-inch diameter restrained columns. Each set consisted of three columns with varying degrees of stiffness in the restraint frame, including low, medium, and high-restraint stiffness. The medium-restraint column provides the theoretical response of new pavement cast against a mature slab, whereas the other two bracket the problem. The column specimens were instrumented using vibrating wire strain gages, which were embedded in the concrete, and load cells, which were affixed to the top of the columns. This research concludes that SCC can be effective even with a stiff boundary condition, and that SCC provides the potential for much longer-lasting airport runway slabs, as a result of reduced shrinkage and therefore fewer cracks.

scholarly journals Application of Vibrating Wire Strain Gages for Evaluating Main Pipeline Stress-Strain State

2021 ◽  
Vol 137 (6) ◽  
pp. 57-61
Author(s):  
А. А. Ignatik ◽  
Keyword(s):  
Strain Gage ◽  
Strain State ◽  
Strain Gages ◽  
Vibrating Wire ◽  
Stress Strain ◽  
Stress Strain State ◽  
Wire Strain ◽  
Wire Method ◽  
Different Diameters ◽  
Longitudinal Strains

The use of anti-turbulent and depressant additives makes it possible to increase the efficiency of oil pipelines trThis article considers the physical basis of the vibrating wire method of monitoring the stress-strain state of the pipe walls. A laboratory experiment performed on a stand for measuring pipe strains during its bending by vibrating wire strain gages is described. The values of longitudinal strains obtained by vibrating wire and electrical strain gage methods are compared. The geometric task of determining the deflection of the strain gage wire when it is installed in the circumferential direction on pipelines of different diameters is solved in order to assess the reliability of the strain gage readings. The main points of the methodology for evaluating the stress-strain state of main pipelines by the vibrating wire method are considered and the classification of pipeline section functional state is proposed.

Accounting for the transverse sensitivity of wire strain gages

1972 ◽  
Vol 15 (9) ◽  
pp. 1316-1318
Author(s):  
O. N. Ivanov ◽  
I. Kh. Sologyan ◽  
A. Kh. Baliullin ◽  
F. D. Chegolyaev
Keyword(s):  
Strain Gages ◽  
Transverse Sensitivity ◽  
Wire Strain

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.

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.

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