REPUBLIKA.CO.ID, JISHOU — Cina punya cara sendiri mengatasi kemacetan. Negara dengan penduduk terbanyak di dunia itu melakukan terobosan baru yang memungkinkan daerah yang terpisah oleh jurang bisa terhubung dengan mudah. Pengendara tidak perlu lagi berdesak-desakan di jalan pegunungan yang sempit dan berliku.
Laman dailymail.co.uk, Sabtu (31/3), melansir Cina meresmikan jembatan yang mempermudah transportasi di daerah Jishou, Provinsi Hunan. Jembatan yang dibangun di atas ketinggian 1.102 kaki ini diberi nama jembatan Aizhai. Aizhai merupakan jebatan keempat yang bisa menyebrangi sebuah lembah luas yang tampak menghubungkan dua pegunungan.
Jembatan model gantung yang mulai dikerjakan sejak Oktober 2007 ini sekaligus memecahkan rekor sebagai jembatan tertinggi. Jarak tempuhnya hampir 4000 kaki.
Pengendara juga bakalan dimanjakan dengan pemandangan Canyon Dehang saat melintasi jembatan itu. Ketika malam hari, sebanyak 1888 lampu siap menyala di sepanjang jembatan.
Jembatan ini memiliki empat jalur yang terbagi menjadi dua arah untuk digunakan mobil dan truk. Pejalan kaki juga diberikan jalan khusus.
Sebelumnya Cina telah memiliki jembatan terpanjang di dunia yang mencapai lebih dari 100 mil. Jembatan Danyang Kunshon ini dibangun dua tahun lalu menghubungkan Beijing-Shanghai menggunakan kereta berkecepatan tinggi.
Looking like a scene from the movie Avatar, the deep canyon dwarfs the north tower in the upper left.
The view from the north side with the short tower shows the taller south tower halfway complete on the far side of the canyon. Image by www.smxxsy.com
An early Aizhai computer rendering. In the final design, the taller tower has a horizontal cross brace with more ordinary antenna-like tower tops. The tunnel was also changed and does not extend under the taller tower.
Several Aizhai bridge tower designs.
One of the cable anchorages located on the back side of the mountain range.
The wire bundles are connected to a deep underground concrete wall.
Aizhai valley wind test model.
Note how close the foliage is to the back span cables.
The tunnel entrances beneath the tall tower.
One of the cables sagged down into the gorge during the early process of setting up the catwalks. The Chinese workers quickly freed up the cable and hoisted it out of the valley.
You can view a video here of the preparation to use a small blimp to take the first pilot line across. http://bbs.rednet.cn/thread-22618784-1-1.html
The hanging cable reveals just how high up the rock face scaffolding is below the south tower.
The catwalks were in place by mid-2010.
The wires are always grouped into hexagon shaped bundles that fit together within the larger main cable like the pieces to a puzzle.
The main cables were completed in the fall of 2010.
A large model was created to show the unique process where the truss sections will be pulled and rolled along hanging cables with wheel bogies attached to them.
One of the massive bogies especially designed to pull the suspended truss sections out over the gorge.
A test section was set up for the traveling bogies. The temporary supports simulate the stringer intervals where the bogies will travel on cables that are connected to the ends of the stringers.
In the above view you can see the process where the suspended truss sections roll along horizontal cables connected to the vertical suspender cables. The large green beam is a crane whose only function is to raise each truss section several meters into place. The yellow wheel bogies travel back to the cliff side staging area to carry another truss section out and the process repeats until the truss is completed. This complex and experimental system was used for the first time ever on Aizhai.
A diagrams shows how the truss is rolled over cables before eventually being raised into place by the green crane that is not shown here. The design may also have been modified as the wheel bogies roll over the blocks at the bottom of each suspender yet the diagram shows the truss below these blocks as well as being pulled along by cables attached to the truss.
The above drawing shows how the truss is raised into position by the green crane that rolls along on the 2 main suspension cables. This crane is only used to raise the truss sections and does not move them horizontally.
Image by www.voc.com.cn.
The most recent rendering showing another design with pointed ornamentation on the tower tops. There is still some question as to which design was chosen for the tower top.
An earlier drawing showing a blue pin stripe paint scheme.
Map of the new highway northwest of Jishou.
A map showing the various Aizhai bridge routes and proposals that were studied. The final route that was chosen is located midway between the red and blue routes.
Several elevation proposals were studied for half a dozen different routes. You can double click on the image to see it more clearly.
Aizhai bridge proposal 1 would have required an unusually long main span of 1,300 meters and a lengthy side span but both towers would have been short.
Proposal C would have had a main span of just 1,100 meters and is similar to the final design.
Proposal M would have had a main span of 1,228 meters but required a tower almost 200 meters high as well as an anchorage resting on a steep mountain slope.