Introduction
Prestressed concrete bridges constitute a substantial portion of the world’s transportation infrastructure. Ensuring their safety requires the timely detection of damage affecting the prestressing system and primary load-bearing components, which may progressively deteriorate due to corrosion, grouting defects, anchorage failures, and other long-term time-dependent effects.
In this context, continuous structural health monitoring (SHM) represents a promising alternative to conventional periodic visual inspections, as it enables both the early detection of hidden damage and the continuous tracking of structural performance throughout the bridge lifecycle.
However, most existing SHM studies have been conducted under laboratory conditions, using reduced-scale specimens and relatively short monitoring periods. As a result, they often fail to capture the complexity of real-world bridges, where environmental and operational variability, evolving boundary conditions, and gradual degradation processes strongly influence structural behavior. Addressing this gap through long-term, full-scale investigations on real structures, supported by high-quality reference datasets and robust SHM methodologies, constitutes the primary motivation for the present project.
Description of the full-scale bridge
The case study is a full-scale, single-span simply supported PSC bridge with a span of 20 m. The superstructure consists of three precast I-shaped girders (0.80 m deep) connected by four rectangular cross-beams (0.6 × 0.3 m), which provide transverse load distribution, lateral stability, and torsional stiffness. A 0.2 m reinforced concrete slab completes the deck.
Girders are cast in C45/55 concrete, while the slab uses C30/40. Reinforcement is B450C steel throughout. Each girder contains five pretensioned strands and one post-tensioned tendon. The strands have a cross-sectional area of 1.39 cm² each; the post-tensioned tendon comprises 12 strands of the same area, positioned approximately 0.125 m above the soffit to limit tensile stresses under service loads. The pretensioned strands are arranged in two layers: one strand at 0.3 m from the soffit and four strands at 0.060 m, spaced at 0.07, 0.13, 0.370, and 430 mm from the outer edge.
Description of the sensor networks
A dense, multi-sensor SHM network is installed on the bridge deck and girders to capture global dynamics, local structural response, and environmental conditions. The system comprises 70 acquisition channels distributed across five sensor types.
Global dynamics are monitored by 10 triaxial MEMS accelerometers (channels M1–M30, ±2 g, noise density 25 μg/√Hz, sampled at 200 Hz), enabling operational modal analysis and identification of natural frequencies, damping ratios, and mode shapes. Co-located biaxial inclinometers (channels R1–R20, 20 Hz) complement the accelerometers by recording low-frequency rotations and joint flexibility.
Local structural response is tracked through strain gauges at midspan on girders 2 and 3 (channels S1–S5, 50 Hz) and load cells at tendon anchorages (channels C1–C3, 50 Hz), providing direct monitoring of sectional strains and prestressing force evolution over time.
Environmental conditions are recorded by 11 temperature/humidity sensors (channels T1–T11 and H1, 1 Hz) via an Arduino-based acquisition system, allowing environmental effects to be separated from structural responses.
| Sensor type | Units | ID (Channels) | Sampling rate [Hz] | Measured quantity |
|---|---|---|---|---|
| Triaxial MEMS accelerometer | 10 | M1–M30 (30 ch) | 200 | Accelerations [g] |
| Biaxial inclinometer | 10 | R1–R20 (20 ch) | 20 | Rotations [deg] |
| Strain gauge | 5 | S1–S5 (5 ch) | 50 | Strains [microstrain] |
| Load cell | 3 | C1–C3 (3 ch) | 50 | Prestress force [kN] |
| Temperature sensor | 11 | T1–T11 (11 ch) | 1 | Temperature [°C] |
| Humidity sensor | 1 | H1 (1 ch) | 1 | Relative humidity [%] |
Real-time data acquisition
Accelerometer data [24/10/2025 from 17:00:00 to 17:30:00]
Load cell data [24/10/2025 from 17:00:00 to 17:30:00]
Inclinometer data [24/10/2025 from 17:00:00 to 17:30:00]
Strain data [24/10/2025 from 17:00:00 to 17:30:00]
Temperature data [24/10/2025 from 17:00:00 to 17:30:00]
Humidity data [24/10/2025 from 17:00:00 to 17:30:00]
Experimental campaigns timesheet
Under construction measurements [28/08/2025 – 06/11/2025]
- [28/08/2025] Ambient vibration test after slab casting – Phase 0: ambient vibration test conducted immediately after slab casting. The bridge was in its most essential structural state: no safety concrete barriers, no post-tensioning cables installed, no prestress applied.
- [17/10/2025] Ambient vibration test after two sides concrete barriers adding – Phase 1: ambient vibration test following the placement of concrete safety barriers on both sides of the deck. The barriers were resting in contact with the slab surface but not rigidly connected to it. Post-tensioning cables were present but not yet prestressed.
- [23/10/2025] Ambient vibration test with only one side concrete barriers – Phase 2: ambient vibration test with safety barriers retained on one side only, allowing assessment of the structural asymmetry introduced by the unilateral mass distribution. Post-tensioning cables remained installed but unprestressed.
- [24/10/2025] Post-tensioned cables prestressing – Phase 3: prestressing operation applied to all post-tensioning cables. One-sided safety barrier configuration maintained throughout. This phase marks the first introduction of active prestress forces into the structural system and establishes the initial cable tension state for subsequent monitoring.
- [06/11/2025] Post-tensioned cables prestressing – Phase 4: safety concrete barriers removed. Prestress applied to all post-tensioning cables. This configuration represents the clean, instrumented structural baseline, all monitoring channels (acceleration, strain, rotation, force, temperature, humidity) are active and recording from this point forward. All subsequent experimental campaigns are referenced against this state.
Load tests [02/03/2026]
- Static load test with heavy veichle: a heavy vehicle was positioned at predefined locations along the deck to induce controlled static loads. Structural response measured in terms of strains, rotations, and displacements under quasi-static conditions.
- Static load test with light veichle: same protocol as the heavy vehicle static test, repeated with a lighter vehicle to assess the linearity of the structural response and allow direct comparison between load levels.
- Dynamic load test with heavy veichle: a heavy vehicle crossed the bridge at controlled speeds to excite the structure dynamically. Accelerations, strains, rotations, and forces recorded to characterize the dynamic response under operational traffic loads.
- Dynamic load test with light veichle: same protocol as the heavy vehicle dynamic test, repeated with a lighter vehicle to isolate mass and speed effects on the dynamic structural response.
Damage scenario simulations [Ongoing]
- [16/04/2026] Damage simulation via added masses: controlled damage scenarios simulated by positioning calibrated masses at selected positions on the deck. Aimed at evaluating the sensitivity of the monitoring system to changes in the structural mass distribution and dynamic properties.
- [Scheduled] Cutting of post-tensioned cables: progressive cutting of the post-tensioned cables to simulate incremental loss of prestress force. Continuous monitoring of all channels allows tracking of the evolving structural response as the cable tension is gradually reduced.
References
Free dataset avalable at the following link:
The link will be available soon…
While using the provided dataset please kindly cite the following publications:
- Mariani, F., Ierimonti, L., Giri, P., Garcìa-Macìas, E., Casali, L., Ubertini, F., Venanzi, I., 2026, PRISM – PRestressed benchmark bridge with Integrated Structural health Monitoring: baseline modal identification under environmental and operational variability
- Castellani, M., Mariani, Giri, P., F., Ierimonti, L., Garcìa-Macìas, E., Ubertini, F., Venanzi, I., 2026, A Remote Sensing Method for Detecting Prestress Loss in Bridges Using UAV-Based Deformation Monitoring, Under review
Aknowledgements
The project is supported by Manini Prefabbricati S.p.A. and the Italian Ministry of University and Research (MUR) through the project TIMING—Time Evolution Laws for Structural Reliability of Post-Tensioned Concrete Bridges (Protocol No. P20223Y947). Additional support was provided within the FABRE–ANAS 2021–2026 research program through FABRE Consortium. The campaign aims to establish a robust, high-quality full-scale experimental database to test, validate, and benchmark continuous SHM methodologies across different structural configurations, explicitly accounting for environmental and operational variability.
