Safety Evaluation for Fabricated Small Box Girder Bridges Based on Fuzzy Analytic Hierarchy Process and Monitoring...

Area of Science:

• Civil Engineering
• Structural Engineering
• Bridge Safety Assessment

Background:

• Fabricated small box girder bridges face significant safety risks including structural degradation and potential failure.
• There is a critical need for robust safety evaluation methods to manage these risks effectively.

Purpose of the Study:

• To quantitatively evaluate the safety status of a fabricated small box girder bridge.
• To develop and validate a novel safety assessment methodology integrating Fuzzy Analytic Hierarchy Process (FAHP) and Structural Health Monitoring (SHM) data.

Main Methods:

• Established a Fuzzy Analytic Hierarchy Process (FAHP) model incorporating stress, deformation, and temperature as key evaluation factors.
• Determined safety thresholds for stress and deformation using industry standards and extensive SHM data analysis.
• Simulated and analyzed the bridge's temperature field using ANSYS, HYPERMESH, and TAITHREM to establish the most unfavorable temperature gradient as a safety threshold.
• Quantitatively assessed bridge safety by calculating index scores based on measured SHM data.

Main Results:

• The determined safety thresholds, derived from industry specifications and SHM data, were found to be reasonable and reliable.
• The developed temperature field simulation model demonstrated consistency with measured results, accurately predicting bridge temperature gradients.
• The safety evaluation outcomes from the FAHP model aligned precisely with field test results, confirming the method's efficacy.

Conclusions:

• The proposed FAHP and SHM integrated approach provides an effective and applicable method for quantitative safety evaluation of fabricated small box girder bridges.
• The study validates the reliability of thresholds set by combining industry standards with massive SHM data.
• The accurate temperature gradient determination through simulation further enhances the robustness of the safety assessment.