Since the implementation of the "Code for Design of Ventilation and Lighting for Road Tunnels" (JTJ 026.1-1999) was published on June 1, 2000, it has been more than ten years since its inception. The scale of road tunnels in China has been continuously expanded, the types have gradually increased, and the design speed has been continuously improved. Ideas and lighting technologies are also constantly evolving, and new materials and equipment are constantly being put into use. In order to adapt to the development of the tunnel lighting situation, the Ministry of Transport revised and expanded the original “Code for Design of Ventilation Lighting for Highway Tunnels†in July 2014, and formed the “Design Rules for Highway Tunnel Lighting†(JTG/T D70/2). -01—2014) and two independent recommendations for “Road Tunnel Ventilation Design Rules†(JTG/T D70/2-02—2014). This paper analyzes the differences between the old and new standards for tunnel lighting design.
1. Differences in tunnel lighting setting conditions
The old standard stipulates that tunnels with a length greater than 100 m should be illuminated. The new standard classifies and refines the setting conditions, and introduces the concept of "optical long tunnel", which I will organize into Table 1.
Table 1 New standard tunnel lighting setting conditions
The new standard also stipulates that tunnels that are required by some people should meet the pedestrian lighting requirements; tunnels that do not have lighting should be equipped with line-of-sight guidance facilities.
2. Differences in design standards
There are big differences between the old and new lighting design standards. In the composition of the lighting section, unlike the old standard, the new standard divides the entrance section into two sections Lth1 and Lth2, and divides the exit section into two sections of Lex1 and Lex2, as shown in Fig. 1 and Fig. 2.
Entrance section lighting design standard
The brightness of the entrance section depends on the brightness outside the hole, and the length of the entrance section depends on the parking line of sight. Compared with the old standard, the brightness outside the tunnel and the value of the parking line have not changed, but the outside brightness and parking line value at 120km/h speed increase, and 120km/h
The reduction factor at the speed of the vehicle. The new standard refines the conditions for the brightness of the entrance section. The author sorts it into Table 2.
Transition section lighting design standard
The transition section of the new standard is consistent with the old standard and is still divided into three sections (TR1, TR2, TR3), but the reference of each section is Lth1 of the inlet section, and the reduction factor is reduced. In addition, the length of the transition is expressed in a formula. For the case where the transition section can be used to enhance the illumination, the new standard puts forward the conditions, and the author sorts it into Table 3.
Intermediate section lighting design standard
Compared with the old standard, the design standard of the middle section lighting of the new standard is quite different: compared with the old standard, the interpolation method is used to determine the intermediate brightness value. The new standard is basically the brightness under the same design speed according to the design peak hour traffic volume range. Curing to 3 levels; the brightness standards of tunnels, emergency stop belts and cross-channels for pedestrians and vehicles are reduced; the requirements for the lighting of the middle section in the curve, the brightness requirements of the diversion section and the confluence section are increased. The new standard also stipulates that for tunnels with longer travel time (more than 135 seconds), the middle section can be further divided into two sections, and the latter section can further reduce the brightness standard, as shown in Table 4.
Export section lighting design standard
Compared with the old standard, the new standard divides the exit section into two sections, and stipulates that a straight tunnel with a length of ≤300m can be reinforced without an exit section and has a length of 300m.
Emergency lighting and exterior lighting design standards
The new standard refines the setup conditions for emergency lighting systems and significantly increases the emergency lighting power supply maintenance time (from 3 minutes to 30 minutes). The brightness standard is consistent with the old standard. The new and old standards have basically the same requirements for the brightness and length of the tunnel outside the tunnel, but the new standard refines the setting conditions of the tunnel outside the tunnel: the curve radius of the tunnel outside the tunnel is smaller than the general road section, the tunnel is illuminated at night and is in the absence. The outer tunnel of the lighting section, the junction of the tunnel and the bridge, and the section between the continuous tunnels.