Damage Analysis of Segmental Dry Joint Full-Scale Prestressed Cap Beam Based on Distributed Optical Fiber Sensing

Area of Science:

• Structural Engineering
• Materials Science
• Sensor Technology

Background:

• Segmental construction with dry joints presents unique structural challenges.
• Understanding the damage mechanisms in segmental beams is crucial for infrastructure integrity.
• Traditional monitoring methods may not capture complex stress states effectively.

Purpose of the Study:

• To evaluate the effectiveness of Distributed Fiber Optic Sensors (DFOS) in monitoring a segmental prestressed bent cap with dry joints.
• To compare the damage progression of a segmental bent cap with a monolithic cast-in-place counterpart.
• To analyze the complex stress states and identify failure modes in segmental beams.

Main Methods:

• Utilized DFOS technology for high-accuracy, wide-range monitoring of structural behavior.
• Compared strain distributions, crack patterns, and damage processes between segmental and monolithic beams.
• Analyzed data across elastic and ultimate load ranges, including neutral axis location.

Main Results:

• DFOS successfully analyzed complex stress states in segmental beams, even beyond elastic limits.
• Identified shear key joints as weak points leading to high stress concentration and accelerated damage.
• Observed premature compression zone formation at the shear key as the primary damage initiation point.

Conclusions:

• DFOS is a viable technology for detailed structural health monitoring of segmental concrete structures.
• Shear key joints significantly influence the damage behavior and reduce the overall performance of segmental beams.
• The findings provide critical insights for the design and maintenance of segmental bridge components.