The precision modeling of dam break floods can lead to formulation of proper emergency action plan to minimize flood impacts within the economic lifetime of the assets.Application of GIS techniques in integration with...The precision modeling of dam break floods can lead to formulation of proper emergency action plan to minimize flood impacts within the economic lifetime of the assets.Application of GIS techniques in integration with hydrological modeling for mapping of the flood inundated areas can play a momentous role in further minimizing the risk and likely damages.In the present study,dam break analysis using DAMBRK model was performed under various likely scenarios.Probable Maximum Flood (PMF)calculated for a return period of 1000 years using deterministic approach was adopted for dam break analysis of the proposed dam under various combinations of breach dimensions.The available downstream river cross-sections data sets were used as input in the model to generate the downstream flood profile.Dam break flow depths generated by the DAMBRK model under various combinations of structural failure are subsequently plotted on Digital Elevation Model(DEM)of the downstream of dam site to map the likely affected area.The simulation results reveals that in one particular case the flood without dam may be more intense if a rainfall of significant intensity takes place.展开更多
Localized nature of damage in structures requires local measurements for structural health monitoring. The local measurement means to measure the local, usually higher modes of the vibration in a structure. Three fund...Localized nature of damage in structures requires local measurements for structural health monitoring. The local measurement means to measure the local, usually higher modes of the vibration in a structure. Three fundamental issues about the local measurement for structural health monitoring including (1) the necessity of making local measurement, (2) the difficulty of making local measurement and (3) how to make local measurement are addressed in this paper. The results from both the analysis and the tests show that the local measurement can successfully monitor the structural health status as long as the local modes are excited. Unfortunately, the results also illustrate that it is difficult to excite local modes in a structure. Therefore, in order to carry structural health monitoring into effect, we must (1) ensure that the local modes are excited, and (2) deploy enough sensors in a structure so that the local modes can be monitored.展开更多
Overhead sign-support bridges that allow displaying necessary information for travelers across the multiple lanes in highways often use large message sign panels: static message sign (SMS) panels or dynamic message si...Overhead sign-support bridges that allow displaying necessary information for travelers across the multiple lanes in highways often use large message sign panels: static message sign (SMS) panels or dynamic message sign (DMS) panels. Along with conventional SMS panel, the use of DMS panel is increasing in highways over time owing to their effective capability to guide the travelers in real-time. A 230-ft long span 4-chord overhead steel truss bridge attached with SMS and DMS panel has been studied through extensive finite element analysis to observe the structural integrity. The static wind load was applied in model truss for four different configurations as per 2016 AASHTO LRFD design specification. The innovative structural detailing approach for truss end support and connection detailing for toll-equipment supporting frame was proposed based on static analysis. The present study will help engineers to design overhead sign support bridges by ensuring both public safety and structural integrity.展开更多
文摘The precision modeling of dam break floods can lead to formulation of proper emergency action plan to minimize flood impacts within the economic lifetime of the assets.Application of GIS techniques in integration with hydrological modeling for mapping of the flood inundated areas can play a momentous role in further minimizing the risk and likely damages.In the present study,dam break analysis using DAMBRK model was performed under various likely scenarios.Probable Maximum Flood (PMF)calculated for a return period of 1000 years using deterministic approach was adopted for dam break analysis of the proposed dam under various combinations of breach dimensions.The available downstream river cross-sections data sets were used as input in the model to generate the downstream flood profile.Dam break flow depths generated by the DAMBRK model under various combinations of structural failure are subsequently plotted on Digital Elevation Model(DEM)of the downstream of dam site to map the likely affected area.The simulation results reveals that in one particular case the flood without dam may be more intense if a rainfall of significant intensity takes place.
文摘Localized nature of damage in structures requires local measurements for structural health monitoring. The local measurement means to measure the local, usually higher modes of the vibration in a structure. Three fundamental issues about the local measurement for structural health monitoring including (1) the necessity of making local measurement, (2) the difficulty of making local measurement and (3) how to make local measurement are addressed in this paper. The results from both the analysis and the tests show that the local measurement can successfully monitor the structural health status as long as the local modes are excited. Unfortunately, the results also illustrate that it is difficult to excite local modes in a structure. Therefore, in order to carry structural health monitoring into effect, we must (1) ensure that the local modes are excited, and (2) deploy enough sensors in a structure so that the local modes can be monitored.
文摘Overhead sign-support bridges that allow displaying necessary information for travelers across the multiple lanes in highways often use large message sign panels: static message sign (SMS) panels or dynamic message sign (DMS) panels. Along with conventional SMS panel, the use of DMS panel is increasing in highways over time owing to their effective capability to guide the travelers in real-time. A 230-ft long span 4-chord overhead steel truss bridge attached with SMS and DMS panel has been studied through extensive finite element analysis to observe the structural integrity. The static wind load was applied in model truss for four different configurations as per 2016 AASHTO LRFD design specification. The innovative structural detailing approach for truss end support and connection detailing for toll-equipment supporting frame was proposed based on static analysis. The present study will help engineers to design overhead sign support bridges by ensuring both public safety and structural integrity.
