Study On The Change Law Of Light Environment And Lighting Design Method In The Connection Section Of Highway Tunnel Group Portal

Mountain tunnel is a common man-made structure of mountain highway.When there are many continuous tunnels,the continuous mutation of light environment at the entrance of the tunnel poses a serious threat to the safety of drivers.Therefore,how to construct a comfortable light environment for connecting section of tunnel group is very important to ensure the safety and comfort of drivers in the process of driving in tunnel group.Based on this,this article based on the 32 km highway tunnel in qinling group,in highway tunnel group of connection segment driver’s visual characteristic as the research object,through the theoretical research,literature research,driving test,the methods of mathematical analysis,connection section of highway tunnel group comfortable light environment construction technology were studied,the main results as follows:1.The illumination and instantaneous change rate of driver’s pupil were used as the evaluation indexes of light environment and visual stimulus respectively.The indoor and outdoor static tests were carried out,and the calculation formula between ambient illumination and pupil diameter was obtained under stable light environment.2.The field driving dynamic test was carried out to verify the spatial and temporal distribution of adaptive time and adaptive distance in and out of single highway tunnel entrance and exit,and the calculation formula of driver pupil diameter in single highway tunnel entrance and exit section was obtained.3.The applicability of the calculation formula of pupil diameter of single tunnel inlet and outlet section in tunnel group section was verified,and the adaptive distance of light and dark outside the tunnel was obtained at different speeds.Finally,the definition of highway tunnel group based on drivers’ visual characteristics at different speeds was given.4.Based on the analysis of the relevant data in the Detailed Rules for The Design of Highway Tunnel Lighting,a classification scheme for the lighting design of the connection section at the entrance of highway tunnel group is proposed: for the tunnel group with tunnel spacing less than 50 m,sunshade should be set and basic lighting should be installed in this section,and the lighting of downstream tunnel should be reduced.For the tunnel group with tunnel spacing greater than 50 m but less than 200 m,lighting design is reduced for the downstream tunnel entrance section according to the tunnel spacing and design speed.For tunnel groups with tunnel spacing of more than 200 m,lighting design can be carried out according to independent tunnel.The above research results were applied to 32 km highway tunnel group in Qinling Mountains,and the effectiveness and economy of the design scheme were verified by the comparison test before and after the lighting design optimization,which proved that it could effectively alleviate the problem of light and shade adaptation of highway tunnel group.It can also provide reference for other similar highway tunnel lighting design.