Research On Optimum Analysis Of Light Distribution In Illumination Environment Of Highway Tunnel Section

In the tunnel entrance section,due to the huge difference in brightness inside and outside the tunnel during the day,a "black hole effect" is formed.This visual phenomenon makes it easy for drivers to make erroneous judgments and causes traffic accidents.This makes the mouth section a high incidence of accidents.In order to alleviate the "black hole effect" of the hole section,enhanced lighting is usually used.The annual electricity bill for highway tunnel operation in the country is as high as 6 billion,and the lighting load for the reinforced section of the entrance hole accounts for about 80%of the total load.The high cost of lighting has forced local operating units to close down part of the light source to reduce operating costs.Unreasonable lights turn off the lighting quality of the tunnel environment and increase the probability of traffic accidents.In this paper,the optimal analysis and research on the"light distribution environment for highway tunnel openings" is carried out.The main research contents and innovation results are as follows:①Optimized analysis and design of light distribution parameters for lighting design.1)For the calculation method of design parameters,this paper analyzes the K value method recommended by the current chinese lighting rules and the perceptual contrast method recommended by the International Commission on Illumination for the calculation model and related parameters,and finds that the visual field range is not equal when the above two methods are compared and analyzed.This paper selects 20°as the comparison field of view,and derives the formula for the equivalent light curtain brightness within the 20° peer field of vision,and the conversion relationship between the brightness of the glare source and the brightness outside the hole.The result of the perceived contrast method is found to be somewhat safe.2)Reference parameters for setting design parameters.To count the cumulative frequency of different weather in Chongqing in different seasons in 2017,the cloudy sky,cloudy sky,and sunny days in the sky model recommended by the International Commission of Illumination are selected as meteorological factors,combing with measured data to analyze the effect of brightness outside the cave.With seasonal changes in the position of the sun,the effect of time characteristics on the brightness outside the hole is analyzed.Based on the above two points,the perceptual contrast method was used to calculate the brightness values of the entrance sections in different seasons in different seasons of the year,and the lighting environment was graded based on a certain brightness difference and the cumulative frequency of weather occurrence as indicators.②Optimization Analysis of Lighting Selection in Section of Entrance.The rational selection of tunnel luminaires is studied in terms of the color rendering of the light source and the color temperature of the light source.By analyzing the color rendering of the light source,a high color rendering index LED lamp source is more advantageous than the high pressure sodium lamp,and the color temperature is obtained by the LED light source.The small-object visibility indoor model experiment shows that the higher the color temperature of the light source is,the better the gain effect on the STV value of the small-object visibility is,and the better the traffic safety is.Based on the above two points,it is concluded that a high color temperature LED light source should be used at the tunnel entrance.③Optimized Analysis and Study on Lighting Arrangement of Entrance Section of Large Section Highway Tunnel.For three-lane large-section highway tunnels,two types of corresponding LED lights,"high-power,large-pitch" and "low-power,small-pitch," are used to design and apply light distribution schemes for different levels of entrance environment.The three-dimensional simulation software DIALUX performs simulation analysis,compares the road lighting quality indicators and energy consumption indicators,and concludes that the adoption of the current specifications of LED lamps can meet the needs of the three-lane section by adjusting the layout,with low power and small spacing.LED lights layout more efficient and more energy-efficient.Innovative point 1.The paper comprehensively considered the physical factors such as time,environmental characteristics,meteorological conditions and other biological factors such as driver awareness,and optimized the reference value of tunnel lighting design,which has important theoretical significance for ensuring the safety of tunnel portal sections.Innovation point 2.Summarize the causes of accidents in the Dongkou section,and use targeted biological indicators such as the visibility of small targets,combined with the environmental characteristics of the cavern sections,and targeted lighting selection.Innovative point 3:For the three-lane tunnel,a new type of low-power lamp lighting method is designed to ensure a safe lighting environment and reduce tunnel energy consumption.