arrow_back_ios

Main Menu

See All Software See All Instruments See All Transducers See All Vibration Testing Equipment See All Electroacoustics See All Acoustic End-of-Line Test Systems See All Academy See All Resource Center See All Applications See All Industries See All Services See All Support See All Our Business See All Our History See All Global Presence
arrow_back_ios

Main Menu

See All nCode - Durability and Fatigue Analysis See All ReliaSoft - Reliability Analysis and Management See All Test Data Management See All DAQ Software See All Drivers & API See All Utility See All Vibration Control See All High Precision and Calibration Systems See All DAQ Systems See All S&V Hand-held Devices See All Industrial Electronics See All Power Analyzer See All S&V Signal Conditioner See All Acoustic See All Current and Voltage Sensors See All Displacement See All Force sensors See All Load Cells See All Pressure See All Strain Gauges See All Temperature Sensors See All Torque Sensors See All Vibration See All Accessories for Vibration Testing Equipment See All Vibration Controllers See All Measurement Exciters See All Modal Exciters See All Power Amplifiers See All LDS Shaker Systems See All Test Solutions See All Actuators See All Combustion Engines See All Durability See All eDrive See All Production Testing Sensors See All Transmission & Gearboxes See All Turbo Charger See All Training Courses See All Acoustics See All Asset & Process Monitoring See All Custom Sensors See All Data Acquisition & Analysis See All Durability & Fatigue See All Electric Power Testing See All NVH See All Reliability See All Smart Sensors See All Vibration See All Weighing See All Automotive & Ground Transportation See All Calibration See All Installation, Maintenance & Repair See All Support Brüel & Kjær See All Release Notes See All Compliance See All BKSV Worldwide Contacts
arrow_back_ios

Main Menu

See All API See All Microphone Cartridges See All Microphone Sets See All Microphone Pre-amplifiers See All Sound Sources See All Acoustic Calibrators See All Special Microphones See All Accessories for acoustic transducers See All Experimental testing See All Transducer Manufacturing (OEM) See All Piezoelectric Charge Accelerometers See All Piezoelectric CCLD (IEPE) accelerometers See All Electroacoustics See All Noise Source Identification See All Environmental Noise See All Sound Power and Sound Pressure See All Noise Certification See All Industrial Process Control See All Structural Health Monitoring See All Electrical Devices Testing See All Electrical Systems Testing See All Grid Testing See All High-Voltage Testing See All Vibration Testing with Electrodynamic Shakers See All Structural Dynamics See All Machine Analysis and Diagnostics See All Dynamic Weighing See All Vehicle Electrification See All Calibration Services for Transducers See All Calibration Services for Handheld Instruments See All Calibration Services for Instruments & DAQ See All On-Site Calibration See All Resources See All Software License Management

How optical fiber sensors are used in the reconstruction of a church destroyed in an earthquake

Earth System, Italy

Introduction

The 18th century church of Santa Maria del Suffragio in Italy was destroyed by an earthquake in 2009. In order to continuously monitor and control the behaviour of the structure, optical measurement technology from HBK FiberSensing supports the monitoring of strain and temperature in the prestressed tie rods used for reinforcement.

chevron_left
chevron_right

Optical sensors collect valuable data for reconstruction project

L'Aquila is an ancient city in central Italy with a rich cultural heritage. Baroque and Renaissance buildings and churches line the streets of the historic city center. Approximately 70,000 people call the town home. And yet the city did not become well-known for its architecture or the landscape of the surrounding Apennine Mountains, but for a catastrophe. In 2009, an earthquake shook the region and destroyed countless buildings including family homes and historical landmarks. The 18th century church of Santa Maria del Suffragio became the symbol of this earthquake.

Seven years have passed since then. Santa Maria del Suffragio was one of the first landmark buildings to be partially restored. The use of provisional supports allowed its partial opening to the public one year after the tragedy. Full reconstruction of the church started in 2013 and is still ongoing. The earthquake did not only cause the collapse of the dome but also resulted in structural deficiencies in the whole building.

INTERNAL USE - Case Study  iat-earthsystems RaBoe_Wikipedia_Santa_Maria_del_Suffragio_2010

The Church of Santa Maria del Suffragio in 2010. Photo: Ra Boe / Wikipedia // Licence: CC by-sa 3.0*

*Photo: Ra Boe / Wikipedia // Licence: CC by-sa 3.0

Reconstruction and reinforcement

The structure is not only being reconstructed, but also seismically reinforced to guarantee the stability and safety of this important landmark in the years to come. In order to continuously monitor and control the structure’s behavior, the reinforcements are being tested by I.A.T. Ingegneria A&T and Earth System, companies focus on measurements for geotechnical, environmental and structural monitoring. Optical measurement technology by HBK FiberSensing supports monitoring of strain and temperature in the pre-stressed tie rods used for reinforcement.

Measuring of strain and temperature at the same time

Fiber Bragg Grating (FBG) sensors were glued to the Dywidag 32WR tie rods to measure strain and temperature at the same time. Each rod connector includes one array consisting of two bare FBGs – one for strain and another one for thermal compensation. When calibrated, the thermal compensation sensors provide absolute temperature values. To make things easier on site, the sensors were designed to be pre-installed at the HBK FiberSensing facilities and then transported to the site. The use of optical splitters simplified the installation of the system and optimize the interrogator’s capacity. Because the above mentioned arrays of FBGs are terminal (meaning that they are only connected on one side), optical splitters are used to combine the signals from several FBG arrays in one optical channel. The splitters used in this case allow 1x4 or 1x8 multiplexing.

INTERNAL USE - Case Study  iat-earthsystems Couplers_for_Dywidag_32WR_tie_rod

Couplers for Dywidag 32WR tie rod

INTERNAL USE - Case Study  iat-earthsystems Installation_of_Fiber_Bragg_Grating_Sensors

Installation of the FBG sensors

INTERNAL USE - Case Study  iat-earthsystems Sensor

Finished sensor

INTERNAL USE - Case Study  iat-earthsystems Sensor_packaging

Sensor packaging

Remote data access

The BraggMETER interrogator acquires all the different optical channels simultaneously at a rate of one sample per second (S/s). The 19’’ rack-mountable device used has eight optical channels. The FS22 Industrial BraggMETERs can be connected to a standard computer by Ethernet cable and controlled by BraggMONITOR software from HBK FiberSensing as well as through SCPI commands or via catman®. The fact that the static interrogator can actually operate as a stand-alone device and store data internally came in handy in this application. The interrogator was connected to a 3G router so that no computer was required on site. Data can be accessed remotely in the comfort of the office with the technician’s laptop.

INTERNAL USE - Case Study  iat-earthsystems Figure_4_-_Bragg_monitor

Industrial BraggMONITOR software interface

FS22SI RM 8OC front

Industrial BraggMETER SI (Rack-Mountable)

About Earth System 

Earth System is a design, production and marketing company in the field of instrumentation, data loggers and software for the acquisition, transmission and management of measurements for geotechnical, environmental and structural monitoring. Our business model is based entirely upon the quest for quality and innovation. Rigorous selection of our suppliers and quality control of the production processes enable us to offer instruments in line with the highest quality standards imposed by the market.

Technology used

Other case studies

Showing 9 of 513 items
No more result to load