Journal of Performance of Constructed Facilities

Due to the designing characteristics of long span and low stiffness, the high-order vortex-induced vibration (VIV) of suspension bridges may occur under a special wind environment. The prototype monitoring data make it feasible to rapidly capture and evaluate the VIV behavior during bridge operation. Based on the multisource load-response data of a long-span suspension bridge in a rare VIV phenomenon, this paper comprehensively evaluated the entire process of the input–output behavior of bridge VIV. The cause of this bridge VIV phenomenon is discussed, and the VIV parameter is estimated. The human comfort of vehicle riding in the VIV phenomenon is evaluated. A fast early-warning method of bridge VIV driven by multisource monitoring data is proposed according to the analysis and evaluation results of the bridge VIV phenomenon. The main results demonstrated that continuous excitation of wind whose direction is almost perpendicular to the longitudinal direction of the bridge are more likely to cause VIV; the Strouhal number of the three-meter-high stiffening box-shape opening-below steel girder is approximately 0.101694 according to the $k$-means clustering of inversely-calculated results of the monitoring data. The evaluation results and proposed early-warning method support the wind-resistant design, health monitoring, and intelligent maintenance of long-span suspension bridges.

Asymmetric scallop cutouts on the sides of a U-rib caused by diaphragm splicing deviation were detected in a bridge. To study the possible effect of this phenomenon on fatigue performance, the stresses of the asymmetric scallop cutout and the diaphragm-to-rib weld were tested, and the influence was compared with that of the symmetric case. This and numerical simulation showed that, for the side of the U-rib with the smaller-radius scallop cutout, the position of stress concentration transferred from the scallop cutout to the diaphragm-to-rib weld, and the stress value of the weld was greater than that of the scallop cutout, resulting in more fatigue damage to the weld. To reduce the adverse effect caused by the asymmetric scallop cutouts, an application experiment with a hammer peening was carried out, and the stresses before and after hammering were monitored. The results showed that hammer peening could improve the fatigue performance by inducing compressive stress.

This study proposes a geographic information system (GIS)–based rapid visual screening approach for seismic vulnerability assessment of masonry buildings in culturally and architecturally important historical regions. Through the application of the proposed methodology, a prioritization strategy for seismic vulnerability assessment of the heritage masonry buildings in Galata, a historical center of Istanbul, Turkey, was performed. This approach is based on an integrated methodology including a data collection process conducted through visual inspections and standard survey forms filled on site, generation of a georeferenced building database enabling the calculations and mapping of the vulnerability scores, and camera-based data validation process. The validation process provides an online collaborative mobile mapping system through georeferenced images gathered from the field. By the updatable data validation process, the reliability and efficiency of the GIS-based building database are enhanced by minimizing the errors during the visual screening and the cost of data correction due to reinspection is reduced.

A discrimination method with drainage or plugging that mitigates the karst tunnel water inrush during operation in a seasonal variation zone is proposed to cope with repeated water inrush disasters. This method identifies the critical-water-pressure working state of the tunnel lining by analyzing the water inrush mechanism during the karst operation period. Based on the working state of the tunnel’s critical water pressure, a more accurate method for calculating the equivalent permeability coefficient of the surrounding rock in the karst tunnel is proposed, and then the treatment principles of plugging and drainage can be distinguished theoretically. By taking the Nanshibi operating tunnel as an example, a field test of water inrush disaster treatment was carried out to testify the effectiveness of the proposed approach. Results indicate that: (1) the discrimination method of drainage or plugging can effectively guide the management of water inrush disasters in operating tunnels, and (2) the grouting plugging plan and grouting treatment effect inspection method proposed for operating tunnels have high applicability.

Tie-down cables are critical components of uplift-restraint bearings in bridges. Damage of a tie-down cable substantially affects the safety of a bridge and driving conditions. In this study, a damage identification method for the tie-down cable in cable-stayed bridges is developed by using vehicle-induced displacement. First, a vehicle-induced displacement is derived through theoretical mechanical analysis. By introducing an area reduction factor for the tie-down cable, a displacement-based damage index is proposed, and the changing regularity of the proposed damage index is comprehensively illustrated in different damage cases. Then, the numerical simulation with the corresponding area reduction of the tie-down cable is implemented for a cable-stayed bridge to validate the rationality of the damage index. The results demonstrate that the proposed damage index is not affected by the weight of the vehicles and is effective in detecting the area reduction of tie-down cables without the information of vehicle weights. The changing regularity of the damage index can reflect the damage cases of tie-down cables. For the actual application of the proposed method, the damage index possessing a minimum initial value, which is obtained when vehicles pass in the outermost lane of a bridge, is optimum.

The apartment buildings erected in New York City between 1902 and 1915 form a specific typology characterized by similarities in structural, architectural, and fire protection solutions. Except for a few municipal buildings and “skyscrapers” of the same period, the facades of this typology contain the highest percentage of ornamentation of New York City’s building stock. Several recent facade incidents have fueled new concerns about the condition of architectural ornaments. In Manhattan alone, about 3,500 buildings belong to this typology. The ornaments include materials such as stone, terra cotta, wrought iron, and pressed metal. Using findings from the examination of a sample of 171 facades of five- to seven-story masonry buildings, the author presents the performance of facade components and identifies their most common modes of failure. The findings are based on observed present deficiencies, comparisons with 1908 illustrations, and evidence of past distress mitigation. The inspections produced numerical results for the facades with deteriorating terra cotta, stone, brick masonry, and metals. This paper represents the first half of a study intended to evaluate the remaining life of the facades of this typology. In the follow-up paper, condition ratings and the history of recent repair activities are used to predict the remaining life of the facades.

The 3,500 apartment buildings erected in New York City between 1902 and 1915 form a typology characterized by similarities in structural and architectural solutions. About 87% of these buildings are still standing and are home to about half a million people. To predict the remaining life of facades of this typology, the author rated the condition of 171 masonry facades. For each surveyed building, a timeline of repairs since 2006 was constructed. The data collected—condition ratings, type of material, and area of ornamentation allowed analysis of the deterioration of various materials as they have been interacting in the same facade. The sample included 74 facades subject to mandated periodic inspections. The results of these inspections performed by others provided additional points of control. The condition ratings and the 13-year timeline of activities were used to predict the remaining life of the facades in terms of rate of repairs. Deterioration developing in stone and terra-cotta ornamentation is the main concern. Corrosion of steel anchoring the ornaments was found to be the main factor determining the deteriorations’ critical path.

Fatigue cracking of orthotropic steel decks is a long-standing problem in bridge structures. The notch stress approach has been applied to the fatigue evaluation of steel structures. Parameters of the notch stress approach in this study include the notch type, notch radius, and level and slope of the fatigue design curve. First, a finite-element model (FEM) for the rib-to-deck welded joint using the notch stress approach is built and influences of notch types and notch radii on the notch stress are analyzed. Then, based on the fatigue test results of rib-to-deck welded joints, notch stress fatigue classification levels under different notch types and notch radii are studied. The notch stress fatigue design curves for the rib-to-deck welded joints are recommended. Finally, a multiscale model of Jiangyin Bridge is built. Based on the recommended notch type, notch radius, and notch stress fatigue design curves, the fatigue life of rib-to-deck welded joints of Jiangyin Bridge is evaluated using the notch stress approach and compared with that using the nominal stress approach and the hot-spot stress approach. The results show that the intersecting notch stress is higher than the tangent notch stress, and the notch stress decreases with the increase of the notch radius. For a weld toe tangent notch with a radius of 1 mm (0.04 in.), the fatigue class 206 (FAT206) fatigue design curve with a slope of 3.5 is recommended to be used. The fatigue class 225 (FAT225) fatigue design curve should be applied to a weld toe tangent notch with a radius of 0.75 mm (0.03 in.). A comparison of Jiangyin Bridge fatigue life evaluation results show that the bridge fatigue life calculated by the notch stress approach is lower than that calculated by the nominal stress approach and the hot-spot stress approach. When the vehicle load is 50% heavier than the fatigue standard vehicle load, the bridge fatigue life calculated by the notch stress approach is only about 5 years.

Bridges have been identified as an essential part of transportation in Taiwan. However, most bridges are experience significant damage from frequent earthquakes, in addition to bridge scour caused by flooding from yearly typhoons and heavy rain. Therefore, implementing a safety assessment and early warning system during bridge maintenance has become an urgent need. Presently, a bridge’s seismic or flood resistance capacity is evaluated by obtaining the required data from the bridge’s design drawings, computation statements, and maintenance inspection data for the estimation of danger thresholds. Extraction of such documents and related information must often be done manually. This study verified the bridge design and maintenance parameters required for safety assessments in terms of seismic resistance evaluation, flood resistance evaluation, and vibration frequency analysis. Relying on the developed data exchange platform, this study innovatively proposes an invisible computer concept to automate the data extraction and analytical process once the required documents and data are uploaded and input in the design and construction phases. During an earthquake, typhoon, or flood in the maintenance phase, the developed system will retrieve the needed data and implement a safety assessment without the requirement of additional user input or interactions. Then the autonomous system will instantaneously send the evaluation results and disaster warnings to the bridge management authorities through mobile facilities for further appropriate actions. The system not only saves time and labor efforts for preemptive measures but also better protects the safety of road users.

Open deck steel bridges are characterized by the direct connection of transoms to the bridge girders. The expansion of steel girders due to thermal loads is transmitted by the fastening system to the track in the transition zones as compressive loads. Adding compressive thermal loads in continuously welded rails (CWRs) and train braking can significantly increase track buckling potential in the transition zones of open deck bridges. This paper treats the static and dynamic track buckling in the transition zones of open deck steel bridges using a multibody train-track dynamic model and a three-dimensional finite-element track model. Considering resilient fasteners and zero toe load (ZTL) fasteners, six fastening profiles are defined. For the train-track interaction, normal and severe braking of wheels is considered. Based on the results, it is concluded that dynamic buckling temperature depends chiefly on steel girder temperature and location of misalignment. Using a combination of resilient fasteners and ZTLs can be an effective way to enhance the performance of CWR tracks on open deck steel bridges.