On December 27,2011,Ran Chengqi,director of the China Satellite Navigation Office announced that,the BeiDou Navigation Satellite System (BeiDou system) had that day begun to provide initial operational service.
Railway transitions experience differential movements due to differences in track system stiffness,track damping characteristics,foundation type,ballast settlement from fouling and/or degradation,as well as fill and s...Railway transitions experience differential movements due to differences in track system stiffness,track damping characteristics,foundation type,ballast settlement from fouling and/or degradation,as well as fill and subgrade settlement.This differential movement is especially problematic for high speed rail infrastructure as the 'bump' at the transition is accentuated at high speeds.Identification of different factors contributing towards this differential movement,as well as development of design and maintenance strategies to mitigate the problem is imperative for the safe and economical operation of both freight and passenger rail networks.This paper presents the research framework and initial instrumentation details from an ongoing research effort at the University of Illinois at Urbana-Champaign.Three bridge approaches experiencing recurrent geometry problems were instrumented using multidepth deflectometers(MDDs) and strain gages to identify different factors contributing to the development of differential movements.展开更多
文摘On December 27,2011,Ran Chengqi,director of the China Satellite Navigation Office announced that,the BeiDou Navigation Satellite System (BeiDou system) had that day begun to provide initial operational service.
文摘Railway transitions experience differential movements due to differences in track system stiffness,track damping characteristics,foundation type,ballast settlement from fouling and/or degradation,as well as fill and subgrade settlement.This differential movement is especially problematic for high speed rail infrastructure as the 'bump' at the transition is accentuated at high speeds.Identification of different factors contributing towards this differential movement,as well as development of design and maintenance strategies to mitigate the problem is imperative for the safe and economical operation of both freight and passenger rail networks.This paper presents the research framework and initial instrumentation details from an ongoing research effort at the University of Illinois at Urbana-Champaign.Three bridge approaches experiencing recurrent geometry problems were instrumented using multidepth deflectometers(MDDs) and strain gages to identify different factors contributing to the development of differential movements.
