Abstract: The lighting in superlarge crosssection urban tunnel is high in energy consumption and low in lighting effect. Accordingly, a case study is conducted on the Haitianbao urban tunnel with an inner contour area of 145.91 m2 in Chongqing, China. Based on the lighting numerical simulation analysis method, the parameters of lighting installation spaceheight ratio are introduced to investigate the influence of lighting design parameters, such as lighting distribution mode, lighting distribution curve, and installation longitudinal spacing, on tunnel lighting quality. The results show that: (1) Under the same spaceheight ratio, the indices of illumination quality, such as the average illumination of road surface, the total uniformity of illumination of road surface, and the longitudinal uniformity of illumination of the middle line of road surface, increase first and then decrease with the increasing spacing of lamps. (2) When the spaceheight ratio is 1.5, the illumination quality index value reaches the highest when using central lighting mode, the longitudinal spacing of 10.5 m, and symmetrical and nonbutterflyshaped light distribution curve. Compared with the original scheme, the average road illuminance, the total uniformity of road illuminance, and the longitudinal uniformity of road midline illuminance are increased by 35%, 38%, and 24%, respectively. (3) It is beneficial to improve the lighting quality of urban tunnel pavement with large crosssection by selecting an appropriate lighting pattern and light distribution curve.

Key words: tunnel lighting, superlarge crosssection, analogue simulation, spaceheight ratio, lighting design optimization