Comfort assessment for rehabilitation scaffold in road-railway bridge subjected to train-bridge-scaffold coupling vibration

Abstract Rehabilitation scaffolding attached to an operating bridge always vibrates during construction works. Hence, individuals working on the scaffold may feel uncomfortable from exposure to excessive vibration. This paper proposes a strategy to assess the comfort of the scaffold with regard to the train-bridge-scaffold coupling vibration. Thereby, the dynamic response of the scaffold subjected to moving train loads can be calculated using a numerical model of the train-bridge-scaffold coupling vibration. The calculation results were compared with the results obtained by an on-site experiment to validate the numerical model. The vibration acceleration level (VAL) recommended by ISO 2631 was adopted as the comfort index to assess the comfort of the scaffold. A case study considering the Nanjing Yangtze bridge rehabilitation project was carried out to demonstrate the proposed procedure. The assessment results revealed that the comfort index was mainly determined by the vertical dynamic response of the scaffold. The distribution and magnitude of the frequency spectrum of this acceleration response were influenced by the structural stiffness and its spatial distribution, structural mass and its spatial distribution, and train speed. Higher structural stiffness and lower mass resulted in a higher VAL. Additionally, the VAL value increased with the train speed increment.

[1]  Chang-Koon Choi,et al.  A new three-dimensional finite element analysis model of high-speed train–bridge interactions , 2003 .

[2]  Yeong-Bin Yang,et al.  A versatile element for analyzing vehicle–bridge interaction response , 2001 .

[3]  Kailai Deng,et al.  Probabilistic analysis of exterior hanging scaffold strength under impact load , 2020 .

[4]  Neil J Mansfield,et al.  Design of digital filters for frequency weightings required for risk assessments of workers exposed to vibration. , 2007, Industrial health.

[5]  Kuang-Han Chu,et al.  Bridge Impact due to Wheel and Track Irregularities , 1982 .

[6]  Kenneth L. Carper.  Structural Failures During Construction , 1987 .

[7]  Renda Zhao,et al.  Dynamic analysis of thin-walled open section beam under moving vehicle by transfer matrix method , 2008 .

[8]  Dan M. Frangopol,et al.  Bridge stress calculation based on the dynamic response of coupled train–bridge system , 2015 .

[9]  A. K. Mallik,et al.  Numerical analysis of vibration of beams subjected to moving loads , 1979 .

[10]  Juraj Králik,et al.  Experimental and Sensitivity Analysis of the Vibration Impact to the Human Comfort , 2017 .

[11]  Masanobu Shinozuka,et al.  Monte Carlo solution of structural dynamics , 1972 .

[12]  Cheng Yang,et al.  Stochastic analysis on flexural behavior of reinforced concrete beams based on piecewise response surface scheme , 2016 .

[13]  Yan Zhu,et al.  Three-dimensional random vibrations of a high-speed-train–bridge time-varying system with track irregularities , 2016 .

[14]  Stephen P. Timoshenko,et al.  History of strength of materials : with a brief account of the history of theory of elasticity and theory of structures , 1983 .

[15]  L. Zuo,et al.  Low order continuous-time filters for approximation of the ISO 2631-1 human vibration sensitivity weightings , 2003 .

[16]  Nan Zhang,et al.  Dynamic analysis of railway bridge under high-speed trains , 2005 .

[17]  Martin G. Helander,et al.  Safety hazards and motivation for safe work in the construction industry , 1991 .

[18]  M. Osama Al-Hunaidi,et al.  Digital frequency-weighting filters for evaluation of human exposure to building vibration , 1996 .

[19]  Renda Zhao,et al.  Reliability Evaluation of Vehicle-Bridge Dynamic Interaction , 2007 .

[20]  Fabian C. Hadipriono,et al.  Analysis of Causes of Falsework Failures in Concrete Structures , 1986 .

[21]  Arnaud Castel,et al.  Modeling the dynamic stiffness of cracked reinforced concrete beams under low-amplitude vibration loads , 2016 .