Stay Cable Damage Detection and Structural Safety Evaluation for Cable-Stayed Bridge After Fire Exposure
This paper presents a method to detect damages of stay cables and evaluate structural safety of the cable-stayed bridge after fire exposure,considering the requirements of bridge fire emergency inspection projects.The fire emergency inspection incorporates four stages,including fire site survey,stay cable burned damages inspection,stay cable damages analysis and structural safety evaluation.Considering the characteristics of fire damages of stay cables,tensile tests were conducted to examine the changes of visual appearance and mechanical property indicators of high-strength steel wires and HDPE sheaths of stay cables after a fire event.Equations to quantitatively calculate the exposure temperatures and damages of stay cables were established.The presented method has been applied to an existing prestressed concrete cable-stayed bridge with a single pylon.It is concluded that the visual appearance and mechanical property of the high-strength steel wires and HDPE sheaths of stay cables show sign of regular changes with the temperature rising.As the temperature rises,the tensile and yield strengths of the high-strength steel wires first decrease,and increase afterwards,the elastic modulus attenuate slowly,and the nominal strain at break of HDPE gradually decrease.After the fire event,the load bearing capacity of the stay cables and main girder meet the requirements,and the overall structure is safe,proving the presented method to detect the stay cable damages and structural safety evaluation is applicable and efficient,which can provide technical support for cable-stayed bridge damage detection,evaluation,maintenance,management and retrofit after a fire event.
cable-stayed bridgestay cablefire damagedamage detectionstructural safety evaluationtensile test
万方数据
维普
