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    The bridge uses large-scale steel structures to illuminate presets and practices

    1 case overview

    This project is the lighting part of the ADB loan Shanxi road development project, the national highway main line Erlianhot to Hekou in the Houmayumenkou highway in Shanxi, and the fourth section of the housing construction project. It is the second ADB loan project in Shanxi Province. It belongs to the national key project and is an important section of the highway planning of Shanxi Province. The quality of its construction and its success directly affect the image of foreign investment in Shanxi Province. And effects. Therefore, leaders at all levels attach great importance to and are listed as key construction projects in Shanxi Province and the only highways in Shanxi Province that were completed and opened to traffic in 2006. The total investment is 2.36 billion yuan, with a total length of 65.561 km. Five toll sheds in the mountains, Hejindong, Hejinxi and Longmen. Among them, the gantry toll shed is the largest, which is the iconic toll shed in the Shanxi Province. The shape is a three-leaf lotus-shaped, 15-lane, the first leaf is across the highway, the length is 111. 9 m, and the highest point is 19. 5 m. The widest point is 36 m (). In this case, the bridge frame is used for the design and implementation of large-scale steel structure lighting with high height, large span, no lamp and pipeline fixed place as an example. For its design and implementation, other toll booths are smaller than this. .

    The steel structure of the toll booth is all curved like a lotus flower, and the curved surface is a film. Under the film is a large space, it is difficult to arrange and fix the lighting fixtures and pipelines, and the size is not well determined. The design does not consider this part of the lighting, and it should be determined according to the specific situation on site.

    2 design requirements

    The large space lighting of the toll shed steel structure has different characteristics and functional requirements from other architectural lighting: 1) The charging shed lighting mainly provides a good viewing angle environment for the past drivers to pay and charge the fees, and to check the condition of the vehicle. Select reasonable lighting fixtures, suitable lighting methods, and meet the GB 50034 2004 architectural lighting design standards for the lighting standards of the building standards and parameters, so that it truly meets people's needs for lighting functions. 2) Because the main line toll booth is located in the tourist area that Hejin City is preparing to develop, it can echo the Yellow River Bridge. Therefore, in addition to meeting its functional requirements, lighting needs to be perfectly integrated with the built environment, and fully apply various lighting means to express the internal and external image of the building, highlight the characteristics of the built environment, and provide reasonable use of different lighting fixtures. Healthy, comfortable light environment. 3) Lighting should also be based on the special requirements of the toll booth, and according to the characteristics of steel structure and large space to prepare reasonable lighting fixtures, light sources and pipelines.

    3 luminaire and pipeline layout design

    3. 1 using steel pipe welding structure

    This kind of scheme can meet the various requirements mentioned above, but it uses too much steel pipe, and it is calculated to weigh several tons, which is not only costly, but also has a great influence on the original steel structure design load, and the pipeline and lamps are not good. Arranged and not beautiful.

    3. 2 cable erection

    This solution can also meet the requirements of use, and the cost is low, but the pipelines and lamps are difficult to arrange, and the steel structure and the surrounding environment are very uncoordinated. Because the toll booth is located at the tuyere on the bank of the Yellow River, the wind speed is extremely large and maximum. Reach eight or more levels. Therefore, the wind and the wire and the wire rope are greatly affected, the lamp is easily scraped off, and the wire rope is easily deformed.

    3. 3 laying with bridge

    This kind of scheme can also meet the various requirements mentioned above, the cost is moderate, the pipeline and the lamp are well arranged, the appearance is beautiful, the steel structure and the surrounding environment are coordinated, the lamp is easy to fix and firm, and the wire rope is firmly fixed together with the bridge frame when the wind is blown. It is as strong as a steel pipe, so it is not deformed and has little effect on the design load of the original steel structure.

    Through comparison of the above several schemes, it is considered that the third scheme is more reasonable, and through the communication and negotiation with the owners, design units and supervision units, a consensus is formed. However, it has certain difficulties in implementation. The main performances are as follows: 1) The bridge design is generally used for fixing by the wall or by the ceiling. No reports or examples for large spaces have been seen; 2) How to fix the bridge in the air 3) How to operate in a large space; 4) How to arrange the luminaire on the bridge.

    In view of the above problems, since there is no data to check or successful experience for reference, it is only through years of construction experience and accumulated knowledge to solve the problem. Through careful calculation and analysis and comparison, the following methods were finally decided: 1) Bridge laying, each steel bridge rope is fixed firmly on both sides of the bridge, and the two ends of the bridge are tightly connected by basket bolts and steel structures, and the bridges are respectively The contact between the end and the steel structure must be tightly and firmly contacted to prevent sloshing when the wind is strong. 2) The bridge frame is specially made to order. In addition to the original hole, two holes are made every 1 m to fix the wire rope. In order to coordinate with the steel structure, the color adopts milky white baking varnish; 3) the steel wire rope adopts galvanized steel, non-deformable special steel wire rope without oil lining, and it is harmful to the water hammer of the building water supply system. Many construction workers often use the actual construction process. Ignore the verification and improvement of it, leaving a safety hazard for the normal operation of the system in the future. Through several years of engineering practice, there are some experiences in the water hammer protection of the building water supply system, which is now summarized and discussed with peers.

    The so-called water hammer phenomenon refers to the pipeline in the pressure pipeline system due to the accidental operation of the gate or valve, the unexpected power failure of the pump unit, the sudden change of the water level in and out of the pool, and the abnormal start and stop of the pump unit. The internal flow velocity changes drastically, which causes the exchange of momentum, which causes the water volume to change, and exerts a huge impact on the pipe wall, water pump and valves, etc. Under the action of water body inertia and compressibility, pipe wall elasticity and system resistance, the water in the pipe The pressure and density alternately alternate until the state of this hydraulic transition process is stabilized.

    The water hammer phenomenon has two forms: direct water hammer and indirect water hammer. When T s (valve closing/opening time) < T (water hammer wave length), the total pressure increase caused by closing the water hammer wave does not interfere with the negative water hammer wave. This water hammer is called direct water. Hammer; when T s > T, the pressure increase caused by the negative water hammer wave is disturbed (ie reduced), and the water hammer peak is cut. This water hammer is called the indirect water hammer. Under the same conditions, the direct water hammer is much more harmful than the indirect water hammer. The most harmful is the breaking of the water hammer.

    1 Theoretical calculation of water hammer pressure value The water supply system shuts off the water hammer pressure peak value P is the superposition value of the pump steady state working lift P 1 and the closed valve water hammer pressure increase P, that is: the bridge is fixed by steel wire bolts; 4) Due to the large span, high wind speed and high height, each bridge is reinforced with steel pipes every 5 m. 5) For the fixtures fixed on the bridge, special methods should be used to fix them, except for fixing by the original fixture fixing method. For example, each set of lamps is additionally reinforced with four sets of bolts to resist the strong wind; 6) For high-altitude operation problems, special operation buckets are used, and cranes are used to lift people in the air. The crane driver requires experience. In order to ensure personal safety, the old driver is required to wear a safety helmet, a seat belt and a safety rope.

    4 lamps and light source selection

    Since the building is in the shape of a lotus leaf, this feature should be fully considered when designing the luminaire and the light source. The building is large and irregular. For direct-illuminated lamps, the efficiency is higher and the energy loss is less. However, the layout and aesthetics of the lamps are generally emphasized. It requires the appearance of the lamps to be coordinated with the architectural style, which can reflect the design of the building. Claim. Therefore, the latest stereotyped diamond silver-white projection lamp with a diameter of 30 cm is selected as the lighting fixture of the toll booth. It has a high refractive index and a beautiful appearance, and is arranged according to the shape of the lotus leaf. 4???, 5???, 5???, 6???, 6???, 7???, 7???, 7???, 7???, 6???, 6???, 6???, 5???, 5???, a total of 15 lines of 85 lights.

    As people's awareness of energy conservation continues to increase, the state's requirements for building energy efficiency are also increasing, and some are also listed as mandatory standards. Therefore, the choice of energy-saving light source should be the first choice. According to the standard, the three-color high-efficiency energy-saving lamp is selected. The white light source with a power of 105 W is equivalent to 500 W of ordinary light bulb, and the light is soft and not glare, which improves the illumination. The environment enables the driver to pass safer, the staff has a more comfortable working environment, and the energy is greatly saved, and good results have been achieved.

    5 actual use effect

    Since it was put into operation, after more than half a year of practice testing, after many major storms and sand blows, it has withstood the test, the operation is stable, and the effect is good, so that the lighting and the building and the surrounding environment are effectively integrated; At the same time, it greatly saves operating costs, saves investment, and achieves good economic and social benefits. Even people who have objections and believe that bridges cannot be used in large spaces, cannot be fixed or insecure, have changed. The views were highly praised by the owners, supervisors, original design units and users.

    6 conclusion

    It can be seen from this design that a good design work not only requires designers to have a broad knowledge, but also has rich practical experience, dare to innovate and keep pace with the times.

    For the lighting design, on the basis of fully understanding the architectural concept, it is also necessary to integrate organically with the surrounding environment, perfectly combining the architectural art and the lighting art, so as to create a first-class lighting environment and fully embody the building. Connotation and effect. For large space lighting, due to the large lighting load, energy conservation and economy should be fully considered.

    Only through unremitting efforts can it be possible to design works that are satisfactory to all parties.

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    女人天堂AV在线

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