Comfort Evaluation of Double-Sided Catwalk for Suspension Bridge due to Wind-Induced Vibration

Zhi-Guo Li,Fan Chen,Xin Chen,Cheng Pei,Jia-Ming Zhang,Giovanni Lancioni

doi:10.1155/2021/6673816

Abstract

Buffeting response of a double-sided catwalk designed for Maputo Bridge was investigated considering wind load nonlinearity, geometric nonlinearity, and self-excited forces. Buffeting analysis was conducted in time domain using an APDL-developed program in ANSYS, and the results were compared with the buffeting response under the traditional linear method. The wind field was simulated using the spectra representation method. Aerostatic coefficients were obtained from section model wind tunnel test. Parameter study has been carried out to investigate the effects of cross bridge interval and the gantry rope diameter on buffeting response. Referring to the ISO 2631-1(1997) standard and the annoyance rate model, the comfort of catwalk due to wind-induced vibration was evaluated. The results indicate that traditional linear calculation methods will underestimate the buffeting response of the catwalk, and enlarging the gantry rope size as well as decreasing the cross bridge interval would increase the comfort level. Moreover, the effect of gantry rope diameter was obvious than that of cross bridge interval. Annoyance rate model can evaluate the comfort level quantitatively compared to the ISO standard.

Highlights

Catwalk structures are temporary walkways used in the erection of main cables in suspension bridges, consisting of a few ropes, steel cross beams, wooden steps, and porous wire meshes at the bottom and both sides [1]
Key conclusions can be summarized as follows: (1) e traditional linear method will underestimate the buffeting response of the catwalk. e nonlinear method proposed in this paper can calculate the buffeting response of the catwalk more accurately
(2) e comfort evaluation method based on ISO 26311-1997 reaches the consistent results with the annoyance rate method. e former method can only evaluate the vibration comfort qualitatively, while the annoyance rate method can give a quantitative result

Summary

Introduction

Catwalk structures are temporary walkways used in the erection of main cables in suspension bridges, consisting of a few ropes, steel cross beams, wooden steps, and porous wire meshes at the bottom and both sides [1]. E psychology of construction workers will be affected by catwalk vibration, including electromyogram (EMG), organ dysfunction, and phenomenon of subjective perception declination Their irritability and error rate would increase, resulting in fatigue thereby reducing the efficiency of construction and affecting the quality of main cable erection. Erefore, it is necessary to evaluate the comfort level of catwalk due to wind induced vibration Researchers put their focus on the aerostatic stability and buffeting response of catwalks. Results show both enlarging the gantry rope size and decreasing the cross bridge interval would boost the comfort level. Where CD(α), CL(α), and CM(α) are the drag force, lift force, and pitching moment force coefficients, respectively, FD, FL, and Mz are the measured drag force, lift force, and pitching moment, respectively, α is the angle of attack, ρ is the air density, V is the wind velocity, and H, B, and L are the height, width, and length of the catwalk model, respectively

Time Domain Buffeting Analysis for the Catwalk

Comfort Evaluation of Catwalk

Concluding Remarks