degree.
Table 1 Japan's tunnel lighting standard, the lighting standard of each section of the entrance lighting, the speed of the tunnel, the full-introduction section, the adaptation section, the over-t-section, the entrance section, the brightness (nt) length (m), the brightness (nt), the length (m), the brightness (nt) Length (m) Full length (m) 75 The brightness of the tunnel interior illumination is determined by the speed of the vehicle and the reflection conditions of the road surface. Table 2 shows the recommended brightness of the CIE for the inner section of the tunnel, which is based on the braking distance and traffic density. Table 3 is the standard for the illumination of the internal section of the Japanese tunnel lighting standard.
Table 2 is the recommended brightness braking distance (m) of CIE for the inner section of the tunnel. Traffic density (vehicles/hour> daytime, when the driver exits the tunnel, it is necessary to prevent the glare stimulation of the brightness outside the tunnel mouth from being reduced or short-sighted. The illuminance of the transition section should be 1/10 of the external illumination of the tunnel entrance, and the length of the transition section should be no more than 80 meters. For the two-way tunnel, the entrance illumination and exit illumination should be further considered.
Table 3 is the Japanese tunnel lighting standard. The standard average brightness (cd/m2) of the internal segment lighting is converted into the average illuminance (lx). The concrete tunnel asphalt road can be correspondingly reduced in tunnel entrance lighting at night. In the exit section, since the illumination outside the tunnel is lower than that of the inner section of the tunnel, a "black hole" phenomenon will occur at night. Generally, a transition section should be set to gradually reduce the illumination level until the night illumination level of the external road is reached. Table 4 lists the night exit transition lighting data that can be used as a design for Japanese tunnel lighting.
Table 4: Japanese tunnel lighting night exit transition lighting tunnel inner section transition lighting I transition lighting transition lighting I transition lighting brightness zone brightness zone length 3 tunnel lighting must be considered human eye visual function human eye is an automatic adaptation to the environment A complex, self-controlled body with varying light intensity. When the ambient light intensity is dimmed from light to dark, the pupil diameter of the human eye will become larger to adapt to the darker environment. This process is called dark adaptation; conversely, when the ambient light intensity is darkened, the pupil diameter of the eye will Smaller to adapt to a brighter environment, this process is called bright adaptation, as shown. During the day when the driver drives into the tunnel, he has to go through a dark adaptation process and go through a bright adaptation process when he leaves the tunnel. These adaptation processes have an impact on the traffic safety of the tunnel. In addition, the high- and medium-level tunnel management systems have reverse driving functions, so the tunnel entrance and exit sections are designed to be symmetrical, as shown.
Illumination gradient gradient map (daytime) The illumination brightness of the tunnel exit section and the entrance section during the daytime should be higher than the basic illumination brightness value in the tunnel, as shown in Table 5; at night, it should be lower than the basic illumination brightness value in the tunnel. When there is street lighting outside the tunnel, the road surface brightness value in the tunnel shall not be less than twice the brightness value of the open air.
Table 5. Section lighting length and road minimum brightness design Vehicle speed introduction section Adaptation section Transition section Entrance illumination distance Brightness distance Brightness distance Total length of brightness area 20 or less The above table is based on the ambient brightness of tunnel entrance at 4000cd/m2. If the brightness outside the hole is greater than or less than 4000 cd/m2, the table value shall be multiplied by the coefficient K0, K0 = ambient brightness outside the hole / 4000. When the hole is provided with dimming measures, it may be considered to shorten or replace the lead-in section.
When the design speed exceeds 80km/h, special research should be carried out.
The basic lighting and night lighting standards in the tunnel are listed in Table 6. Table 6 Basic lighting and night lighting brightness design Speed ​​average road surface average brightness conversion average illuminance (lx) Concrete road asphalt road 20 and below average illuminance conversion factor: 13 (concrete road); 22 (asphalt road).
When the design speed exceeds 80km/h, special research should be carried out.
4 The choice of light source and luminaire in tunnel lighting The appropriate choice of lighting source and luminaire is the key to ensure the quality of tunnel lighting. In addition to the main requirements of light efficiency, luminous flux, life and working characteristics, light color, color rendering and ease of control of light distribution in tunnel-specific environments, the source of tunnel illumination should also be selected to form smoke exhaust in automobiles. A good source of visibility is still guaranteed in the smoke. In the research of Jiangxi's key transportation research projects: electromagnetic induction lamps in the tunnel lighting system, the electromagnetic induction lamps and high-pressure sodium lamps were used to reconstruct and compare the south and north tunnels of the Yanlieshan (2) tunnel of Jiujing Expressway. Perform various performance tests on the reconstructed tunnel lighting system, analyze the test results and various data, and explore the characteristics and adaptability of the electromagnetic induction lamp instead of the traditional high-pressure sodium lamp applied to the tunnel lighting system, and make necessary preparations for popularization and application. The specific project reality is shown in the figure. The effect of applying electromagnetic induction lamps and high pressure sodium lamps is as shown. After nearly half a year of trial use, the driver can greatly improve the driver's vision due to the high luminous efficiency (801m/w), long life (more than 10 years) and good color rendering (Ra>80) of Hongyuan electromagnetic induction lamp. Reaction time, visual acuity and contrast sensitivity.
In October 2004, the China Mainland Expressway Administration specially invited experts to hold an demonstration meeting on the application of electromagnetic induction lamps to tunnel lighting in Fangxing Building, Nanchang City, Jiangxi Province. The experts at the meeting unanimously confirmed their effectiveness in the transition and exit sections. And put forward valuable suggestions for improvement on the inlet section, especially the advantages of the life of the electromagnetic induction lamp for more than 10 years, which is considered to be of great value in overcoming the difficulty of maintenance, cost and safety in tunnel lighting. . In our experiments, the selected lamps were specially designed and manufactured by foreign companies such as the United States. They not only paid great attention to good light distribution performance, but also selected lamps with reasonable dimensions, strong corrosion resistance, aging resistance, moisture resistance and jet repellency.
Of course, our work is only beginning. Next, we are going to use 2-3 thousand sets of Hongyuan electromagnetic induction lamps in the Nanchang-Jinggangshan Expressway tunnel. We welcome people with lofty ideals to cooperate with us and provide assistance to make the tunnel lighting in mainland China reach the international advanced level.
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