Refine Search

New Search

Results: 6

(searched for: doi:10.12989/was.2017.24.5.405)
Save to Scifeed
Page of 1
Articles per Page
by
Show export options
  Select all
Wenbo Gao, , Quanke Su, Wanshui Han
Structure and Infrastructure Engineering pp 1-15; https://doi.org/10.1080/15732479.2021.1875486

Abstract:
The presence of rigid central clamps (RCCs) minimises the damage potential of short suspenders and expansion joints in in-service long-span suspension bridges. The study presented in this paper evaluated the impact of the presence of RCCs on the longitudinal deformation of a long-span suspension bridge under live load with vehicle braking and random traffic flow excitations. Two finite element (FE) models of the bridge were developed – one with RCCs and the other with a traditional suspender (TS) at mid-span. The impact of RCCs and TS on the structural system response was evaluated by comparing the dynamic characteristics of the models. The exceeding probabilities of longitudinal deformation under different traffic flow levels during the design reference period were obtained. The simulation results show that the RCCs are capable of reducing the longitudinal deformation by 35% to 45%. The unfavourable exceeding probabilities of longitudinal deformation over the design threshold decreased from 1.0 to 0.0002, showing that the RCCs could be an effective measure to enhance the service life of the shortest suspender and expansion joints of long-span suspension bridges.
Chunxi Ge,
Structure and Infrastructure Engineering, Volume 15, pp 1567-1582; https://doi.org/10.1080/15732479.2019.1625416

Abstract:
The Sutong Bridge with a span of 1088 m is supported by 272 cables, whose lengths range from 152.85 m to 576.77 m (the longest in the world). The half-year vibration acceleration data of two cables from structural health monitoring system (SHMS) is analysed, in conjunction with the wind field data, weather data and vehicle data to explore and three types of cable vibrations. The large-scale cable vibration is mainly rain-wind-induced vibrations (RWIV) when the wind direction lies in an angular range of 40°–80° relative to the cable axis, and the bridge-deck wind velocity is 4–20 m/s. The ultra-long cable also experiences in-plane vibrations, which satisfy many characteristics of vortex-induced vibrations (VIVs). Cable VIV occurs only when the bridge-deck wind velocity 4–8 m/s, with the frequency ranging from 9.5 Hz to 10 Hz. The daily small-amplitude vibration of the cables and steel girder is mainly induced by the passage of heavy trucks. There exists a positive correlation between the number of heavy trucks and the vibration level. Based on the characteristics and occurrence probabilities of these three types of cable vibrations, corresponding measures are suggested for the maintenance of ultra-long cables.
Published: 6 March 2019
by MDPI
Sensors, Volume 19; https://doi.org/10.3390/s19051133

Abstract:
Dynamic responses of highway bridges induced by wind and stochastic traffic loads usually exceed anticipated values, and tuned mass dampers (TMDs) have been extensively applied to suppress dynamic responses of bridge structures. In this study, a new type of TMD system named pounding tuned mass damper (PTMD) was designed with a combination of a tuned mass and a viscoelastic layer covered delimiter for impact energy dissipation. Comprehensive numerical simulations of the wind/traffic/bridge coupled system with multiple PTMDs (MPTMDs) were performed. The coupled equations were established by combining the equations of motion of both the bridge and vehicles in traffic. For the purpose of comparing the suppressing effectiveness, the parameter study of the different numbers and locations, mass ratio, and pounding stiffness of MPTMDs were studied. The simulations showed that the number of MPTMDs and mass ratio are both significant in suppressing the wind/traffic/bridge coupled vibration; however, the pounding stiffness is not sensitive in suppressing the bridge vibration.
Renaude Carneiro Dos Santos, , João Olympio De Araújo Neto, Augusto César Barros Barbosa, José Venâncio Marra Oliveira
Journal of Civil Structural Health Monitoring, Volume 9, pp 63-76; https://doi.org/10.1007/s13349-019-00322-1

The publisher has not yet granted permission to display this abstract.
Fenghui Dong, Jin Cheng
Published: 1 January 2019
Structures Buildings, Volume 172, pp 17-29; https://doi.org/10.1680/jstbu.17.00083

Abstract:
An inverse reliability-based approach is proposed to estimate the aerostatic stability safety factors of long-span cable-stayed bridges in order that the reliability of long-span cable-stayed bridges against the failure mode of aerostatic stability must meet a desired level of safety. For the purpose of estimation, uncertainties associated with the basic wind speed at the bridge deck location, critical aerostatic stability velocity, the wind conversion factor from a scaled model to the prototype structure and the gust speed factor are taken into account. The proposed approach combines the concepts from the inverse reliability method and the calculation method of the critical aerostatic stability velocity of long-span cable-stayed bridges. A procedure of the proposed approach for the estimation of aerostatic stability safety factor, at the same time, achieves a target reliability is outlined. The proposed approach is illustrated with three existing long-span cable-stayed bridges. The results indicate that the proposed approach provides validity information concerning the accuracy in the estimation of aerostatic stability of long-span cable-stayed bridges over traditional method. Additionally, the effects of various parameters on the aerostatic stability safety factor of long-span cable-stayed bridges are analyzed and discussed.
Dong-Hui Yang, , Hong-Nan Li, Yu-Feng Zhang
Journal of Civil Structural Health Monitoring, Volume 8, pp 5-15; https://doi.org/10.1007/s13349-017-0257-0

The publisher has not yet granted permission to display this abstract.
Page of 1
Articles per Page
by
Show export options
  Select all
Back to Top Top