Damage Detection in Long Suspension Bridges Using Stress Influence Lines

Recent progress and future trends on damage identification methods for bridge structures

“…Several vibration‐based damage diagnosis algorithms for the Alfered Zampa Memorial suspension bridge, that is, changes in the flexibility matrix method, changes in the stiffness matrix method, changes in the uniform load surface method, and uniform load surface curvature method are implemented by Talebinejad et al to detect various damage cases in different structural components with different severities, and the corresponding numerical analysis is conducted in which the damage intensity is increased from 50% to 100% for a suspender and increased from 25% to 90% for the deck; damage in the deck and suspenders is easily detected even with low damage intensity of 25%, whereas damage in the tower leg cannot be detected. Chen et al introduced a damage diagnosis method utilizing stress influence lines (SIL) to locate the damage on different suspension bridge members; the first‐order difference of SIL is selected as damage index, and the location of single and double damage cases simulated in TsingMa suspension bridge can be effectively identified; damage is simulated by reducing cross‐sectional area of the diagonal truss element and the flexural rigidity of the railway beam member to 1% of their original values respectively; damage in the diagonal truss element is more likely to be identified by SIL‐based indices for neighboring top and bottom chords, vertical posts, and suspenders; damage in the railway beam is more likely to be identified by SIL‐based damage indices for neighboring railway beams, cross frames and bracings, vertical posts, and suspenders. Miao et al proposed a damage identification method for the main girder in the long‐span suspension bridge based on the mean‐value control chart method and dynamic displacement data collected from GPS subsystem; 3% abnormal change of position coordinates in the longitudinal direction, and 5% in the vertical direction can be effectively detected.…”

Damage quantification of beam structures using deflection influence lines

“…As Chen et al pointed out, a DIL under a moving load essentially represents a row or subrow in the flexibility matrix F . Past studies on flexibility‐based damage detection will shed light on damage detection using DIL.…”

“…Static damage detection methods based on static or quasi‐static influence lines (ILs) have recently emerged, which only requires the displacement or strain measurement in a short term. Consequently, the effect of temperature load and zero drift could be conveniently removed in these IL‐based methods, given that the measurement duration of ILs is considerably shorter in comparison with environmental changes . Zaurin and Catbas measured the unit IL of a four‐span bridge model by combining video imaging and sensing data.…”

“…Subsequently, they experimentally verified that ILs can be a promising damage indicator . Chen et al explored a group of damage localization indices on the basis of stress ILs for a long‐span suspension bridge and validated their effectiveness through a numerical case study of the Tsing Ma Bridge, whose main span is 1,377 m. Zhu et al further improved the accuracy of damage localization by fusing the information of multiple ILs. Meanwhile, the feasibility of extracting ILs of a bridge from moving‐vehicle‐induced responses has also been verified by using various methods …”

Structural Health Monitoring Based on Vehicle-Bridge Interaction: Accomplishments and Challenges

“…This framework was used to obtain the load rating of bridges (Catbas et al 2012). Chen et al (2015) proposed a regularization method to identify the stress influence lines (SILs) based on the on-site measurement of train information and traininduced stress response in local bridge components, and it was found that the first-order difference of SIL change was an accurate indicator of the damage location. Cantero and Gonzalez (2015) presented a bridge damage detection technique for short-to-medium-span bridges using weigh-in-motion (WIM) technology.…”