Remote Control Structural Monitoring of the Construction of the Tajo’s Viaduct’s Central Arch Span

Álvaro Gaute Alonso, Universidad de Cantabria

"The combination of NI PXI hardware solutions and LabVIEW software creates the perfect tool to monitor the structure of construction processes used in civil engineering."

- Álvaro Gaute Alonso, Universidad de Cantabria

The Challenge:

Monitoring the construction process for building 324 meters of light for the Tajo’s Viaduct’s central arched span using the incremental launches technique by remote control.

The Solution:

Using NI PXI technology and LabVIEW software to carry out the remote monitoring of the replies of a total of 133 sensors distributed on the most significant points of the structure under test.


Álvaro Gaute Alonso - Universidad de Cantabria
Carlos Diego Alonso - Universidad de Cantabria


The combination of NI PXI hardware solutions and LabVIEW software creates the perfect tool to monitor the structure of construction processes used in civil engineering.




To implement the structural monitoring of the Tajo’s Viaduct’s central span during its construction, we planned the instrumentation using the following sensors:

•30 x load cells: These devices record the strain suffered by the viaduct’s provisional suspension cables. They fit between the cable’s anchoring plate and the distribution plate embedded in the cell. This way, the device can determine the flow of compression stress between these two elements. 




•48 x unidirectional passivated steel strain gages: These record the deformation of the passivated steel used in the construction of the arch and the startup of the viaduct’s cells 11 and 17.

•16 x high precision inclinometers: These record the rotation of the significant sections of the arch as well as of the tops of cells 11 and 17 and the provisional towers.

•24 x temperature probes: These register the temperature of the significant sections of the arch, cell 11, the north tower, and the provisional suspension cables.

•8 x load cells in prestressed connector: These sensors record the stress in the Macalloy bars that materialize the provisional towers’ anchorage on the deck.

•4 x accelerometers: This type of sensor determines the acceleration experimented by the arch's sections, which coincide with the location of the bridge’s tower cranes.




To control all the sensors, we designed an acquisition system formed by the following:

•2 x NI PXIe-1078 chassis

•9 x NI PXIe-4330 modules

•2 x PXI-6224 boards

•2 x NI PXIe-4357 modules

•1 x NI PXIe-4492 module

•1 x PXI-4462 module





With the structural monitoring system designed for this project, we can carry out the complex engineering work needed to build the arched central span of the Tajo’s Viaduct with the assurance that the actual work will resemble the project.




Author Information:

Álvaro Gaute Alonso
Universidad de Cantabria
Avenida de los Castros 44
Santander 39005
Tel: 942201735 671121395




Figure 1. Construction of the Tajo’s Viaduct’s Central Arch Span
Figure 2. Tajo’s Viaduct’s General Instrumentation Plan
Figure 3. Installation of Load Cell on the Suspension Cable
Figure 4. Installation of the Accelerometer on the Suspension Cable
Figure 5. Remote Monitoring Program of the Tajo’s Viaduct’s North Margin