Fig. 8 Main girder structure with corrugated steel webs
These two structural characteristics make the prestressed concrete composite box girder with corrugated steel webs have the following advantages compared with the prestressed concrete box girder bridge:
(1) remarkable economic benefits, saving building materials: replacing heavy concrete webs with corrugated steel webs can reduce the weight of superstructure by 20 ~ 30%. Therefore, the workload of the upper and lower structures is reduced, and the total project cost is reduced. ?
(2) Improve prestress efficiency and structural performance: the longitudinal stiffness of corrugated steel webs is small. It can hardly resist the axial force. Therefore, there is no resistance when prestress is introduced. Longitudinal prestressed tendons can be concentrated on the top and bottom plates. So as to effectively improve prestress efficiency. ?
(3) improve material efficiency: in corrugated steel web PC? In box girder bridges, concrete is used to resist bending. Corrugated steel webs are used for shear resistance, and the bending moment and shear force are borne by the top, bottom and corrugated steel webs respectively. The stress distribution in the web is approximately uniform. Instead of triangle in the traditional sense, which is beneficial to the function of materials. ?
Figure 9? Stress state of steel web
(4) Improving the efficiency of cross-section structure: corrugated steel web PC? The concrete of box girder bridge is concentrated on the top and bottom plates. The radius of gyration increases almost to the maximum. The structural efficiency of this part is greatly improved.
(5) the self-weight is reduced. Good seismic performance: the web of prestressed concrete box girder bridge with corrugated steel webs adopts lighter corrugated steel plates. Compared with ordinary prestressed concrete box girder bridge, the dead weight of the bridge is reduced by about 20%. Therefore, the influence of earthquake excitation is significantly reduced. The seismic performance has been improved to some extent. ?
(6) Field operation can be reduced. Speed up the construction process: corrugated steel web PC? In the construction of box girder bridge, a large number of formwork, supports and concrete pouring projects can be reduced, and the complicated process of burying pipes in concrete webs can be omitted. In addition, corrugated steel webs can be produced in factories. On-site assembly construction, thus speeding up the construction progress. ?
(7) During construction, corrugated steel webs can be used as temporary facilities, saving facility costs and speeding up construction: steel webs can be used as part of hanging baskets during cantilever casting, as guide beams during jack-up construction, and web templates can be omitted during cast-in-place. ?
(8) The number of segments of cantilever bridge is reduced. Shorten the construction period: due to the light weight of the beam, the number of segments can be reduced during cantilever construction. ? For example, Japan's Bengu Bridge needs 39? Duan,? However, after using corrugated steel webs, only 3 1 section is needed. The number of segments has been reduced by 20%? . The standard span of this bridge 120m was originally designed as 3 1, but now it is designed as 23, which can greatly speed up the construction. Shorten the construction period. ?
(9) External prestressing tendons can be replaced. Convenient bridge maintenance and reinforcement: corrugated steel web PC? Box girder bridge adopts external prestress to bear live load. Therefore, even after long-term operation, when the external prestressed cable is worn or broken, it can be replaced after stopping traffic at night to restore the bearing capacity and strengthen the structure.
(10) avoids the problem of web cracking. Good durability: the traditional prestressed concrete box girder bridge is affected by external load and concrete shrinkage and creep. Cracks often appear on the paper web. A series of problems, such as weakening of concrete section, corrosion of steel bars and even maintenance and reinforcement, have become common problems of prestressed concrete box girder bridges in China, while PC with corrugated steel webs? Box girder bridges will not have the above problems. Good durability. ?
(1 1) Beautiful shape: The corrugated steel webs are vivid and colorful, which can give the bridge a strong aesthetic feeling.
General situation of Henan Dajian Steel Structure Co., Ltd.
Henan Dajian Steel Structure Co., Ltd. is a system product supplier and technical service provider integrating bridge design, bridge steel structure production and bridge steel structure construction services. With a registered capital of 30 million yuan, the company is the first professional manufacturer of corrugated steel web PC bridge design, construction service and corrugated steel web in China, and can provide customers with a package of solutions integrating corrugated steel web slab bridge design, corrugated steel web processing and corrugated steel web PC bridge construction service.
Dajian steel structure production base is located in wugang city, Henan Province, adjacent to Wuyang Iron and Steel Co., Ltd. of Hebei Iron and Steel Group, covering an area of 100 mu. It has two most professional bridge steel structure production lines in China, with an annual output of 654.38+10,000 tons of steel members and a designed production capacity of 200,000 tons. Dajian Steel Structure has the first high-standard corrugated steel web production line in China and the largest forming equipment for corrugated steel webs in China, with a maximum pressure of 5,000 tons and a daily output of 150-200 tons.
Dajian Steel Structure is a group member of China Steel Structure Association and vice president of Henan Steel Association of China Steel Structure Association. It has the first-class qualification of steel structure manufacturing enterprise and the third-class qualification of steel structure engineering professional contracting, and the second-class qualification is currently being declared. And passed the "ISO? 900 1:2008 quality management system certification. As the most professional manufacturer of corrugated steel webs in China, Dajian Iron and Steel Co., Ltd. currently holds 2 patents 12 related to corrugated steel webs PC bridges, and has published many monographs and papers on corrugated steel webs PC bridges.
Dajian steel structure is committed to PC bridges with corrugated steel webs as the starting point. Through 4-6 years of efforts and the establishment of EPC business model, the company will become a small giant in several distinctive market segments of domestic bridges and building steel structures, realize sustained industrial growth and land in the capital market.
What is the company spirit? The enterprise spirit of "diligence, exploration, truth-seeking and innovation" always adheres to the business philosophy of "market-oriented, innovation-driven, survival by quality and development by reputation", the quality concept of "every detail should be improved" and the highest commitment to customers is "customer satisfaction is our service standard", so as to continuously improve the competitiveness of enterprises and provide customers with the most valuable services.