Zhong Da Consulting has compiled the knowledge of architectural knowledge column of this website, and the basic contents of tunnel design standards are as follows:
In the process of tunnel engineering design, the construction enterprise has made corresponding regulations on tunnel design lighting, and the relevant regulations are as follows:
Tunnel lighting is different from ordinary road lighting. Because of its obvious particularity and importance, it plays a vital role in tunnel traffic safety. Lighting design plays an important role in tunnel. This paper mainly introduces the main characteristics of tunnel lighting, the factors affecting tunnel lighting and the problems that should be paid attention to.
First, the adaptive characteristics of human eyes to light
According to the structure of eyes, visual cells are composed of pyramidal cells and rod cells. The sensitivity of these two kinds of cells to light is different. Rod cells have high sensitivity to light, while pyramidal cells have low sensitivity to light. In bright environment (when the brightness is higher than several Candeira per square meter), pyramidal cells mainly participate in visual work. This visual state is called bright vision; In the dim environment (brightness is several Candeira per square meter), rod cells mainly participate in visual work, which becomes dark vision; When the brightness is between bright vision and dark vision, rod cells and cone cells work at the same time, and cone cells and rod cells have different sensitivity to light. Vertebral cells are most sensitive to light at 555 nm, and rod cells are most sensitive to light at 507 nm.
Eyes can see things clearly not only in sunlight, but also in moonlight, which is mainly related to the exchange of pyramidal cells and rod cells, the change of pupil size and the chemical changes of retina. When the brightness changes greatly in the visual environment, the sensitivity of vision to the brightness changes in the visual environment is called adaptation. There are two kinds of adaptation: light adaptation and dark adaptation. When people enter the bright environment from darkness, they will feel dazzling at first and can't see the surrounding scenery clearly, but they will return to normal vision after a while. This adaptation is called light adaptation: when people enter the darkness from a bright environment, they can't see anything at the initial stage, and after gradually adapting to the darkness, they can distinguish the outline of the surrounding objects. This process of lowering human visual threshold from bright to dark is called dark adaptation. The adaptation time required for dark adaptation and light adaptation is long or short according to the specific situation. Generally speaking, the light adaptation time is short and the dark adaptation time is long.
Second, the tunnel lighting settings
Tunnel lighting can be divided into lead-in section, adaptation section, basic section and exit section according to different sections, and its functions are as follows:
(1) Lead-in section: the lighting section that eliminates the "black hole" phenomenon and enables the driver to identify the obstacles at the entrance.
(2) Adaptation section: the lighting section that enables the driver to quickly adapt to and eliminate the "black hole" phenomenon after entering the tunnel.
(3) Transition section: the lighting section that enables the driver to gradually adapt to the lighting in the tunnel.
(4) Basic section: the basic lighting section in the tunnel.
(5) Exit section: During the day, the driver can gradually adapt to the strong light at the exit and eliminate the "bright hole" phenomenon; At night, the "black hole" phenomenon at the exit can be eliminated, so that the driver can clearly see the linear shape of the external road and the obstacles on the road in the hole.
The design brightness of tunnel lighting is determined in two different situations: day and night. During the day, the illumination brightness of the exit section of the tunnel is the same as that of the entrance section, which should be higher than the basic illumination brightness value in the tunnel; At night, on the contrary, it should be lower than the basic lighting brightness value in the tunnel. When there is street lamp lighting outside the tunnel, the road surface brightness value in the tunnel should not be less than 2 times of the outdoor brightness value.
Three. Tunnel lighting sources and lamps
The choice of lighting source and tunnel lamp is the key to ensure the quality of tunnel lighting. The choice of tunnel lighting source should not only meet the main requirements of light efficiency, luminous flux, life and working characteristics, light color and color rendering, and the difficulty of controlling light distribution in the specific environment of the tunnel, but also ensure good visibility in the smoke formed by automobile exhaust. Therefore, in general, it should be suitable for low-pressure sodium lamps or high-pressure sodium lamps with good visibility in smoke. If it is a short tunnel or a tunnel where diesel vehicles travel for a short time, the smoke will be less, and fluorescent lamps with relatively good color rendering can also be used. High-pressure sodium lamp and electrodeless lamp with high light flux can be used for lighting at the entrance of tunnel. When choosing lighting lamps, we should pay attention to choosing lamps with reasonable size, strong corrosion resistance, no aging, moisture-proof and blowout prevention. Illuminator should have
Fourth, the layout of tunnel lighting lamps and lanterns
Besides the brightness distribution, the layout of tunnel lighting lamps should also consider the flashing, induction and convenient maintenance of lamps. There are three main layout forms. Namely, relative arrangement, staggered arrangement and central arrangement. In order to avoid the unpleasant feeling of "flicker" caused by the discontinuous direct light of the lights entering the cab from the side, the lights should be installed on both sides or in the center of the top of the tunnel as far as possible, and the installation height should be 4m higher than the road surface. The lighting lamps are linearly distributed. In general, the brightness uniformity of pavement should not be less than 0.35.
V. Lighting power supply and emergency lighting
When tunnel lighting is extinguished due to sudden power failure or other reasons, it is easy to cause dangerous accidents in complete darkness. Therefore, the power supply requirements for tunnel lighting are higher. Generally, there should be two independent power supplies, and emergency lighting should be set up. The brightness value of emergency lighting should not be less than one tenth of the basic brightness value, and emergency lighting must have an independent power supply system.
To sum up, the main factors involved in tunnel lighting are: the average brightness of the road surface, the uniformity of the average brightness distribution of the road surface, the degree of glare and flash, the inductive arrangement of lamps, the selection of lamps and light sources, and the continuity of lighting. This should be considered in the design. Due to the particularity and importance of tunnel lighting, it is easy to cause traffic accidents and endanger personal safety if it is not considered properly or set improperly, so tunnel lighting should be paid enough attention.
Remarks: For more information about tunnel design specifications, relevant construction personnel can log on to architectural knowledge column of Zhong Da Consulting.
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