Research Of Urban Overpass High Mast Lighting Disability Glare Based On Digital Simulation

With the rapid socio-economic development of the city, urban overpassconstruction has appearing mushroomed in various cities. The traffic safety ofthree-dimensional transport is gotten attention, especially the night driving safety. Dueto a wide area of the overpass, it uses high mast lighting to meet the functionallighting. To safeguard the safety of night driving, it needs detailed study on the lightenvironment quality of the overpass. Thus, the National Natural Science Foundation（Project No.：51178299）-"based on high-dynamic image technology of urbanoverpass lighting security research" is hosted by Professor Wang Lixiong in TianjinUniversity, and the group gives in-depth research. In this paper, as the second phase ofthe Fund, it mainly researches the high mast lighting overpass, which is digitized.Calculate the values of the glare index. And analyzes the generate law of thedisability glare. In the last, it forecasts the glare limited index.This study investigates the construction features of urban overpasses and highmast lighting conditions in Beijing and Tianjin. It analyzes different structure ofoverpass, separating overpass, as well as the luminaire, luminaires, poles height andpole position etc. of high mast lighting. Finally, this paper proposes a typical overpassdigital model and the high mast lighting parameters based on the DIALux softwareplatform. By determining the typical model and lighting parameters, it will provide abasic condition for the further study on the rules generated by overpass glare.As domestic and foreign lighting standards, were not explicitly mentionedoverpass glare evaluation index, previous studies using the threshold increment (TI)as its index, but it did not form a conclusion. In this paper, it also researches anotherindex-glare ratio (GR), which is used to evaluate the lighting quality of outdoor areasand stadium. This paper also analyzes the calculation principle both TI and GR. Then,it calculates the values of TI and GR used in the typical overpass model, andrespectively compares with the corresponding standard values. Finally, wepreliminary propose that the GR is more valuable to research the disability glare onthe overpass high mast lighting.So, in this paper, we use GR to research the generation rules of disability glare inthe overpass high mast lighting. First, we make the typical model digital. Then, weuse lighting design software DIALux to calculate the glare evaluation index-glareratio. In the last, we get a series of GR values by changing the pole height and lighting elevation angle. Through the data analysis, this paper researches the rules of disabilityglare generation in the overpass high mast lighting.As overpass’s complex form, this study suggests that the value cannot be used oneGR as the evaluation index in overpass, it should give GR limit values based on thecharacteristics of different parts of the overpass. And this paper predicts the values ofGR through software simulation.