Zaozao junction
ancient times
The splay bridge is in Shaoxing, Zhejiang. It is the oldest stone bridge in Shaoxing, with four-year inscriptions in the Southern Song Dynasty. The deck layout is very distinctive. The east end of the bridge descends from north to south along the river, and the west end of the bridge descends from southwest. A small hole was also built under the ramp south of the western end to cross the river. Although it has experienced more than 700 severe winters and summers and has been rebuilt many times, it still maintains a quaint appearance. What is even more rare is that the figure-of-eight bridge can solve such complicated traffic problems structurally. It plays an important role in the history of Chinese bridges and is an important physical specimen for studying the history of Chinese bridges.
Modern Times
1928, the United States first built the first interchange at the intersection of two roads in New Jersey. 1930, Chicago builds overpass. From 193 1 to 1935, Sweden has built overpass bridges in some cities.
exchange
Overpass, the full name of which is "Interchange Overpass", is a modern land bridge built at an important traffic intersection in the city, which is layered up and down, travels in multiple directions and does not interfere with each other.
Spanning form
interchange
Cross existing lines. It is also divided into separation and intercommunication. The former only ensures the independent passage of vehicles on and off the line; The latter can make the upper and lower vehicles pass each other, build complex roundabout ramps on the plane and elevation, and occupy a lot of land. To reduce noise, prestressed concrete bridges are often used.
Didao bridge
Crossing the existing line from underground. It consists of bridge holes, approach roads and ancillary structures. Underground pipelines need to be removed during construction, and the ancillary works are large, which is far less economical than the construction of overpass bridges. In addition, the design should also pay attention to the requirements of clearance, ventilation, lighting, drainage and anti-icing (cold area).
Xin junction
Compared with the traditional butterfly overpass, the new overpass project takes the patented new "four-grade overpass" which does not occupy land as an example. This overpass is 2.5 meters and 5 meters clear from the ground, that is to say, no overpass in the world can be lower than this height.
Yanshan junction
Judging from the traffic volume, the four right turns in the east-west direction and the north-south direction are completely unaffected. Four left turns, we turn on the turntable with a clear height of 2.5 meters from the ground, which is also in line with traffic rules and safety. Right turn accounts for 20% and left turn accounts for 20%. We think it's no problem to make 20% of the traffic turn left at 90 degrees on the turntable. This 2.5-meter-high turntable has three functions: first, it provides a special passage for pedestrians and non-motor vehicles on the ground; The second is to complete the function of turning left and right through the turntable. Third, the car can turn around on the overpass through the turntable. From the overall appearance, the height of grade four overpass is less than10m, and this overpass can be built at ordinary intersections, meeting the requirement of minimum turning diameter14-20m. According to my PCT international patent application, there is no overpass that does not occupy an area in the world. And the cost of the overpass is also very low. Drivers will not go the wrong way, even if they go the wrong way, they can turn around on the turntable of the bridge. It should be appropriate to build this new intersection bridge in the city.
example
Rainbow Expressway Interchange-the highest urban interchange in East China. Looking down from the air, you can see the overpass extending in all directions and overlapping layers, spreading its wings like a butterfly and towering above Times Avenue.
Karamay Road Viaduct, a five-story overpass across Hetan Road, is 34 meters from the highest point on the ground. There are eight direction ramps in four directions, and you can turn left or right in each direction. The length of the five-story interchange bridge across the river beach is 65 1 m, and the length of the ramp and auxiliary road is 3680.9 m. The first floor is Hetan Road, the second floor is the existing Hualing Market Overpass, the third floor is Hetan Road turning left into the ground road, the fourth floor is the ground road turning left into Hetan Road, and the fifth floor is the Karamay Road viaduct connecting the east and west outer rings.