1 Overview
The Taihai Street Beihai Road Overpass is located at the intersection of Tianjin Taida Street and Beihai Road. TEDA Street is the Tongjin Link of Beijing-Tianjin-Tanggu Expressway, which is the main channel for the communication between Tianjin and Tianjin and Tianjin Port. Beihai Road is one of the important trunk lines of the Tianjin Development Zone, and is part of the planned Central Line of Binhai New Area. Therefore, the overpass becomes a node where the expressway intersects with the urban main road. The overpass is about 2.24km long from east to west and 1.5km wide from north to south. Its structure is designed as three floors above ground and one underground. It is a fully interchanged overpass. The highest point of the overpass bridge is about 24m from the ground, which is equivalent to the height of the nine-story building. The majestic overpass is straight and stretched, and it is like a blue sky flying rainbow. In the open and flat area, it is tall and tall and beautiful.
The location of the overpass is in the central area of ​​the Tianjin Development Zone. The southwest of the overpass is the location of the management committee of the development zone and the center of the administrative and economic activities of the development zone. The southeast of the bridge is the cultural and educational zone. There are primary schools, middle schools, and TEDA colleges. It is the concentration of cultural education in the development zone. The northeast side of the overpass is a large-scale international event venue such as the International Convention and Exhibition Center and the TEDA International Football Stadium under construction and its supporting hotel facilities. Therefore, the overpass is a transportation hub and an important place for human activities.
The main purpose of the construction of the overpass is to meet the requirements of the traffic function. Due to the characteristics of the overpass, the constraints of the space and the influence of the design concept, the shape and main structure of most overpasses are basically the same, and it is impossible to leave too much room for aesthetic design. Landscape lighting must use the unique rendering function of the light, using color, brightness contrast and other methods to make it as bright and beautiful as possible.
The lighting project of the bridge is a whole, and it should have a unified style and coordinate with each other. Lighting design is to use the good combination of illumination, brightness and color. Through the contrast of light and dark, strength, weakness, size, height and density, the transition is smooth, the combination of points and faces forms the overall melody of beat coordination, reflecting the modern atmosphere and showing the Tianjin Development Zone. Style.
The lighting design of the overpass itself consists of functional lighting and landscape lighting. Functional lighting is mainly to solve the night driving roads, bridge lighting, broaden the horizon, guide the driving direction, ensure traffic safety, smooth, and improve transportation efficiency. The purpose of landscape lighting is to reflect the three-dimensionality of the overpass by appropriate lighting techniques according to the characteristics of the bridge, and to express the beautiful appearance of the bridge from an aesthetic point of view. The building that stretches and smashes the hustle and bustle and the continuous flow of lights and lights form an organic whole that combines dynamics and statics, which weakens the place that is not beautiful, and makes the beautiful place more beautiful. Using the light art effect, create a comfortable, comfortable and beautiful environment culture, improve the artistic atmosphere of the region, and form a lighting landscape node with the overpass as the core.
Landscape lighting is a kind of lighting project in the art category, not only to make it bright, but also to make it artistic and beautiful, to form a special landscape in a specific environment. Therefore, the lighting design is not indiscriminately lit, but it is not as bright as possible, but should be the use of light and dark contrast, the light is bright, the dark is dark, just right, moderately beautiful. The bright environment is suitable for a warm, festive atmosphere and lively and bustling occasions. The landscape lighting of the overpass should be based on the bridge body, highlighting the dignity of the bridge. In order to achieve the overall consistency and harmony, before the construction design, the design of the overall landscape lighting of the overpass was carried out by the British Lidingling International Lighting Design Co., Ltd. (LDPI), and the overall artistic effect of the overpass area was carried out. Unified planning and guidance. Then the construction drawing design was carried out by our hospital.
The author introduces some ideas in the design of overpass lighting and the various methods adopted for this purpose, and discusses with you, the purpose is to throw a brick.
2 Design of functional lighting for overpasses
The functional lighting design of this project is mainly divided into high pole lighting in the central area of ​​the overpass, road lighting in the outreach part of the overpass, and tunnel lighting. The functional lighting is mainly controlled by direct light distribution.
2.1 Overpass central area lighting
In the central area of ​​the overpass, the roads are concentrated, and the bridges overlap vertically and horizontally. If the method of arranging ordinary road lighting facilities on the bridge is adopted, the following consequences will result: 1 the light poles are crowded and dazzling, and the lights between the upper span bridge and the underpass road cross each other, which is prone to glare, affecting driving, and greatly Increase the amount of engineering; 2 The design of the pole position and the height of the pole on the bridge must be combined with the position of the bridge structure pier, it will be difficult to ensure the uniformity of illumination; 3 the vibration of the bridge body during driving will greatly affect the life of the light source on the bridge.
Therefore, it is not appropriate to use the light poles on the bridge for lighting in the central area of ​​the overpass. This design adopts the practice of concentrating lighting fixtures at high points, that is, using high pole lighting. Four 35m high pole lights are installed in the central area, which is responsible for the main road and bridge lighting in the central area of ​​the overpass. Reduce the phenomenon of poles, fully utilize the characteristics of high poles and high illumination radius, improve illumination uniformity, reduce engineering quantity and limit glare.
2.2 TEDA Street Road Lighting
The central part of the overpass is basically a straight line segment to the surrounding area. On the basis of meeting the requirements of the specification, the common street lamp poles are symmetrically arranged on both sides to improve the road lighting inducibility and save investment. The east-west road of the overpass is Taida Street, which is connected to the Tonggang Road, so the lighting effect must be balanced. Lighting equipment must not only ensure the characteristics of the overpass lighting, but also must be compatible with the original road lighting, taking into account the overall lighting continuity of the road. Do not form an excessively strong contrast, nor create bright spots with strong stimuli in the bridge area. Therefore, the illuminance design on the road should be the same as or slightly higher than the road outside the district, and gradually transition.
In addition, because most of the road lighting outside the overpass uses high-pressure sodium lamps with high luminous efficiency, good fog permeability and long life as the main light source (color temperature is mainly 2800K warm white, forming a slightly yellowish lighting effect), in order to highlight the characteristics of the viaduct. In order to meet the needs of landscape lighting, within the area of ​​the overpass lighting area, on the road in the direction of TEDA Street, 16m high ordinary street light poles are arranged along the road. It is equipped with a half-beam type lighting fixture, and uses a 4000K white metal halide lamp as the main light source. Therefore, it is slightly different from the original road lighting of the city.
2.3 Beihai Road Lighting
The guiding ideology of road lighting design in Beihai Road is the same as that of Taida Street, but it is only necessary to coordinate with the original road lighting of Beihai Road. No longer.
2.4 Ramp lighting
The overpass has elevated ramps and ground ramps. The elevated ramps are the main content of the landscape lighting of the overpass. The functional lighting is solved by high pole lights. Part of the ground ramp is only used as a supplement to the low-lighting of the lower part of the bridge. It is illuminated by ordinary poles, and the light source uses a light source that is consistent with the dominant color temperature in the area. The ground ramp uses a 10m high-light pole to be fitted with a half-cut type luminaire.
2.5 tunnel function lighting
The overpass bridge Beihai Road passes through the Taida Street under the tunnel, and the tunnel is a key point of the project. The length of the tunnel is about 37.5m. From the perspective of functional lighting, there is a big difference between the brightness of the tunnel and the outside of the tunnel. When a high-speed vehicle passes through a tunnel, it is difficult for the driver to adapt to the glare formed by the black-and-white contrast, which may cause a decline in visual function. The "black hole phenomenon" that enters the tunnel moment will also make the driver feel uncomfortable. Therefore, although the tunnel interior lighting and the tunnel exterior lighting are two separate parts of different ranges, there is no special requirement for this, but the transition process at the junction is the focus of the lighting project must be carefully analyzed and carefully considered. The lighting should be scientifically designed at the joint, and efforts should be made to gradually change the brightness, giving the driver an adaptation process as much as possible to ensure a good visual effect. Combine tunnel functional lighting with landscape lighting. Gradually change the light intensity, produce a gradual effect, and meet the process requirements of the driver to adapt to the environment.