Research on monitoring temperature difference from cross sections of steel truss arch girder of Dashengguan Yangtze Bridge

Based on health monitoring system installed on steel truss arch girder of Dashengguan Yangtze Bridge, temperature differences from cross sections of top chord, arch rib chord, bottom chord and diagonal web member are specially monitored and researched through extreme value analysis, correlation characteristics analysis and probability statistics analysis. On this basis, yearly extreme values of temperature differences are simulated for the whole service period by combination method of Monte-Carlo simulation and Newton iteration, and furthermore standard values of temperature differences with exceeding probability of 2% are calculated by generalized extreme value distribution function. And main research results reveals that: (1) obvious temperature differences actually exist in the cross sections of chord members and diagonal web member; (2) uniform temperature action actually exists in cross sections of chord members and diagonal web member at night, and temperature differences in the daytime commonly increase under solar radiation; (3) temperature differences from cross sections of top chord, diagonal web member and arch rib chord increase or decrease simultaneously; (4) Weighted sum of three Weibull distribution functions can well describe cumulative probability characteristics of daily extreme samples; (5) generalized extreme value distribution function can well describe cumulative probability characteristics of simulated yearly extreme values, and correlation scatter plots between calculated standard values and monitoring extreme values show good linear relationship.