World's Longest Cross Sea Bridge | China's Mega Projects | Free Documentary

[Music] this will be the world's longest cross sea bridge and will take about six years to complete 4 000 ships and 1 800 planes pass this construction site every day 500 000 tons of steel and 2.3 million tons of reinforced concrete will be used the tunnel will be the world's longest immersed tube the world's largest vibrating hammer will also be used to build two artificial islands which must be impervious to typhoons and earthquakes and serve to prevent environmental pollution this project has been a dream for generations and this is just the beginning hong kong with an area of 1100 square kilometers and a population of over seven million has become asia's most prosperous area thanks to international finance foreign trade and tourism jew high originally a fishing village is considered china's most livable coastal city macau has a population of 400 000 in an area of only 21 square kilometers making it one of the most densely populated areas in the world [Music] now chinese engineers plan to link the three cities completion of the bridge will provide hong kong with more room for growth while juhai would get a boost from hong kong's economy and macau will be able to expand its tourism market so far this is just a dream the structure of the seabed is very complicated the natural environment harsh and the gap almost prohibitively wide bridging this span of over 30 kilometers appears to be an impossible mega project bridge engineer has headed a team devoted to building another huge project for the past 10 years the hangzhou bay bridge this experience has prepared him to come to juhai for an even more challenging project the hong kong juhai macau bridge project [Music] foreign [Music] connecting hong kong with macau and juhai via the ling ding sea will require solving many problems it would be easy to simply copy the hangzhou bay bridge but conditions here are very different this is the world's most important sea trade route with over four thousand ships coming through daily the complex seabed will further complicate the project moreover the area is often hit by typhoons making it a risky project as well finally the engineers are restricted by a certain rate i.e 10 the weak current in the ling ding sea deposits tons of silt every year the bridge piers would tend to collect silt if their resistance to the water exceeds 10 percent this would eventually block the sea route and transform the ling ding sea into an alluvial plane the engineers must ensure this doesn't happen first of all shipping must not be interrupted there is a crucial deep water channel close to hong kong that is the only channel that can handle large freighters construction of this bridge could threaten this channel [Music] in order to accommodate a 300 000 ton ship the bridge would have to be 18 meters high with bridge towers as high as 200 meters it would certainly be scary driving across such a high bridge besides which the nearby hong kong airport does not allow any structure over 88 meters high in its flight path since this deep water channel cannot be blocked by a mega bridge the designers looked for other solutions otherwise the project would have to be shelved before the project was shelf for good though designers came up with the crazy and bold proposal to dig an underwater tunnel instead in 2009 the chinese government approved the most imaginative plan ever attempted for spanning a body of water in chinese history it calls for a 6.7 kilometer deep water tunnel and a 22.9 kilometer bridge it would be the largest longest and most complicated such project ever built in china completion of the project would shorten the travel time from juhai or macau to hong kong from four hours to just half an hour chinese engineers have already built six cross c bridges but they have never before built such a huge undersea tunnel the bridge project would be an unprecedented challenge engineers faced a problem soon after construction began an island was required to connect the bridge in the undersea tunnel but there was no suitable candidate the only solution was to build an artificial island the detailed sea floor survey however indicates that building such an island would be an unimaginably huge project more than eight million cubic meters of silt equivalent to three egyptian pyramids would need to be removed from the site dumping it elsewhere in the ocean would create an unacceptable level of pollution the plan calls for completing the island within a year so the engineers needed to quickly come up with a better idea the engineers drew up a clever plan to use steel cylinders to make a levy around the island site the steel cylinders would be secured on the seabed in a circle and then the circle would be filled with earth to form an artificial island this approach also eliminates the need to remove huge amounts of silt making it far better for the environment a total of 120 huge steel cylinders will be used to form an artificial island at each end of the tunnel the diameter of each cylinder is 22.5 metres roughly the size of a basketball court at the height of a 28 storey building a 55 meter cylinder weighs up to 550 tons that's as much as an airbus a380 the first problem was finally solved but now the design team must overcome the second problem how to dig an undersea tunnel in the 6.7 kilometer long deep water channel the engineers first considered the proven shield technique [Music] the equipment is available to do the job but it would increase the water flow resistance above the 10 limit ruling out this time-tested technique an island one kilometer long would be unacceptable the only other option is an immersed tunnel which requires first digging a trench on the seabed the prefab tunnel sections are then dropped into the trench and assembled underwater this type of tunnel would not require such long artificial islands so though the smaller islands will reduce the impact on the ocean environment the technology required will present a greater challenge [Music] this will be the most challenging undersea tunnel project in the world each section is 180 meters long 33 meters wide and 11 meters high each consists of the lanes for both directions of a three-lane highway plus a lane on each side for equipment and workers and each section weighs 76 000 tons that's equivalent to the weight of an aircraft carrier the sections will be dropped into the trench one by one starting from the western island where they will then be remotely joined making the huge reinforced concrete sections proved to be more difficult than the engineers ever imagined the engineers finally solved the problem by making eight smaller units for each section and then joining them together this resolved the first big hurdle in the project the engineers now turned their attention to making the huge steel cylinders needed to form the artificial islands which will also be a first for china [Applause] shanghai is the largest chinese eastern coastal city and china's largest international financial centre chengxing island 30 kilometers from the city centre is china's largest shipyard the shipyard uses many thousands of tons of steel each day to produce huge ships for clients from all over the world the steel cylinders used for the hong kong zhuhai macau bridge project are manufactured here as well work on the cylinders continues night and day so that the islands can be formed as soon as possible joe commutes between his office and shipyard every day the team has the arduous task of producing 120 steel cylinders within eight months the cylinders are too large to make in one piece so an alternate method must be found each cylinder could be made of 72 pieces but the more pieces there are the easier it is to have problems when they are assembled the error deviation must be controlled within plus or minus 3 centimeters for a structure as tall as an 18 storey building the team decides instead to first make a steel form work in which to form the shape of the steel cylinder which reduces the error to a controllable level the twelve thousand nine hundred and sixty pieces of steel weighing a total of sixty thousand tons are enough to build eight eiffel towers in eight months the steel will become 120 huge steel cylinders one thousand 300 kilometers from shanghai is densely populated hong kong the trade and financial centre of asia great efforts have to be taken to increase any single point of gdp the bridge will strengthen economic ties in the region and greatly expand opportunities for development in hong kong mr lee realizes what this project will mean to hong kong an experience ten years ago brought him to the design team hong kong relies on its port for foreign trade increased business opportunities in the chinese mainland have created the need for more efficient transportation in the region shenzhen port is the obvious choice for a bridge to the mainland hong kong needs to pursue new opportunities in china's western region for continued economic growth mr lee and his team accepted this challenge in the hopes that the project will promote hong kong's development the scale of the project is unprecedented the 6.7 kilometer long undersea tunnel will require 330 000 tons of steel and two million tons of concrete that's enough for eight skyscrapers all the sections need to be finished in one and a half years to keep the project on schedule this requirement forces engineers to find a way to shorten the manufacturing time [Music] the team looked for help from a world-class german formwork maker that was involved in building europe's longest undersea tunnel called the orson bridge the team hopes the experience of the german engineers can be applied to this project and the difference to the tunnel from arizona is the profiles were smaller as here we work with more bigger profiles and the important thing is we follow exactly some measurements from the drawing otherwise we have on our assembling on the job site a lot of problems you need this working platform that you can work here a framework plan that will allow rapid assembly will greatly accelerate the project sooner the increase in efficiency would ensure that the project stays on schedule the cost of the equipment however would put the project way over budget the chinese engineers have to accept the challenge of producing the most sophisticated automatic framework system in the world the framework will require 3 000 tons of steel and must be produced in just a few months this is a huge challenge for a team with no experience in this area [Music] six months later the last of the still framework is almost finished the workers must finish final assembly and testing in under three days when the framework will be disassembled and loaded on ships for transport to the plant 1 600 kilometers away that is installing the immersed tunnel on guishan island 1 600 kilometers away over 3000 workers are busy preparing for the arrival of the framework they need to build a super factory from scratch in just 100 days the factory's only mission is to produce 33 sections for the world's longest undersea tunnel three million cubic meters of earth needs to be removed from an area equivalent to 10 football fields the factory will produce two sections a month each weighing 76 000 tons in the coastal city of dalian 1990 kilometers away an important series of trials is underway the results will help engineers determine how to successfully install the 33 sections the trials will simulate how the ocean currents might impact the transportation installation of the sections the resulting data should tell engineers the size of steel cable needed to safely drag the 76 000 section into place if the trial does not yield accurate data and the cable breaks during the actual operation an extremely expensive section would sink to the bottom of the ocean and become worthless there could even be casualties the wave maker simulates heavy waves striking the model of a section the trials which take over six months to complete help the engineers determine the best way to safely move the huge sections into place macau is the most densely populated city in the world the city's single industry model is stifling its development in this era of economic globalization city officials are actively looking for new development directions to attract more visitors and partners the success of this project is crucial for the city's development is a tour guide with more than 10 years experience who is looking forward to the increase in tourists that completion of this project will bring [Music] [Music] miss lee also wants to become a tour guide when she graduates from a tourism school the new bridge may very well help expand her career opportunities [Music] but almond [Music] [Music] she wants everyone to know about macau's [Music] culture is sure that tourism is the key to macau's future and that the new bridge will attract more young people to the tourist industry the future is very bright for macau [Music] typhoons and huge waves in the ling ding sea will always pose a threat to the bridge but there is also an invisible and greater threat to the project [Music] a group of chemicals known as chlorates foreign [Music] will be an extremely great threat to this bridge with a design life of 120 years chai and his team must find an effective way to reduce this threat [Music] the data from the 20-year test yielded an effective method for dealing with the chlorate problem a concrete that is highly resistant to chlorate penetration [Music] the 22 kilometers bridge will require 500 000 tons of steel a world record though all steel bridges are much lighter than traditional concrete bridges they do not hold up as well in an earthquake shear and his team have to figure out the best way to protect this steel bridge against earthquakes the engineers turned their attention to one of the latest materials to be developed foreign is now carrying out trials to determine the best shock absorbing system for the bridge before actual construction on the project starts there will actually be three bridges across the ling ding sea which is traversed by over 4 000 ships a day [Music] the design of the bridges is now in the final stage there has never been a bridge like this that crossed three air lanes so close to an international airport the jujo bridge will be only a few kilometers from macau airport and thereby poses the greatest risk since planes will fly over the bridge less than a minute after takeoff normally the hoisting equipment would be much taller than the bridge towers but aviation officials do not allow any structure taller than 122 meters and the design calls for the bridge towers alone to be 120 meters tall [Music] a new and creative method was developed to erect the towers the cable support towers will be assembled ahead of time and pulled into place horizontally with cables and then pulled up into the upright position the new solution seems satisfactory but the operation may still have to deal with strong winds [Music] typhoons are common here and there are around 200 days of strong winds a year steel girders tend to rhythmically swing in the wind if their swinging frequencies are the same resonance will occur and the consequences could be disastrous professor joe is advising his students as they carry out tests at tongji university in shanghai they are using a wind tunnel to resolve the resonance problem foreign it is a key to address the vortex issue and the phenomenon must disappear [Music] foreign this 30 kilometer wide sea channel is the busiest in the world ensuring that the normal traffic of 4 000 plus ships plus the ships involved in the project can traverse the construction area will prove a huge challenge once construction actually starts engineers work with the marine traffic police to redraw the shipping channels it is the largest rerouting ever attempted in china guangzhou maritime vts monitoring center is closely monitoring all ships in the area to ensure the safety of the project is in the final stage of manufacturing the steel cylinders and actual project construction will soon begin [Music] [Music] foreign [Music] transporting the cylinders to the construction site 1 600 kilometers away would be an arduous task five people have to work 10 hours straight loading eight of these steel cylinders onto the ship it's a challenge of both strength and endurance one 70 000 tonne freighter can only carry eight cylinders at a time it seems as though it should be easy for such a big ship to carry these four thousand tonne cylinders but they are 45 meters tall and stand directly in the captain's line of sight the highly experienced captain has never before encountered a challenge like this [Music] um [Music] leaves for the ling sea 1 600 kilometers to the south carrying eight huge steel cylinders the plant making the tunnel sections in guishan island 1 600 kilometers away will soon be finishing its task of making the huge steel framework it took only six months to complete the factory one month ahead of schedule foreign the last piece of framework is being lifted into place assisted by a crane four workers are joining the piece of framework weighing over 10 tons to the rest of the framework in another month work on the first section of the tunnel will start setting another new world record [Music] ship jinhua is approaching juhai it took only 20 years to develop from a small fishing village into a city with a population of 1.5 million the new hong kong zhuhai macau bridge will make it easier for the city to participate in international trade and economic affairs as another important city on the west bank of the pearl river mr zhang moved to juhai 20 years ago soon after the country instituted the reform and opening up policy he has witnessed the changes in jew high over the years [Music] [Music] mr zhang believes that imagination is the city's future he is eagerly awaiting completion of the bridge which would make zhuhai even better [Music] the freighter is carrying the eight steel cylinders to the site of the artificial islands in juhai a tropical storm is gaining strength south of the philippines so time is of the essence thousands of eyes are watching the ship and it's gargantuan cargo which will soon become an important part of the east artificial island accurately placing the huge steel cylinders on the seabed within plus or minus two centimeters is an extremely challenging task mr chun a crane operator is the only one qualified to operate the world's largest eight direction vibrating hammer which is specifically designed for creating artificial islands it can easily lift objects weighing 1 600 tons [Music] the 550 tonne steel cylinder is slowly lifted and moved toward the designated spot but nobody at the site knows its exact position data transmitted from a gps satellite 20 000 kilometers above is used to accurately pinpoint the location the gnss base station has been built to ensure the accuracy of the location the 550 ton steel cylinder is now slowly sinking on its way to the seabed 37 meters below the operation is going well until the hammer stops when the steel cylinder hits a 5 meter thick layer of very hard material [Music] chun gradually increases the hammer's output power in order to avoid overloading the hammer and breaking it [Music] meanwhile nessat the most powerful typhoon of the year is rapidly heading towards the south china sea project command center promptly begins making emergency preparations in case the typhoon reaches the construction site it's a critical moment for the placement of the tunnel sections chen is engaged in a battle with the seabed using the largest vibrating hammer and any mishap could spell disaster a task scheduled for 30 minutes has already taken nearly two hours and the wind is now whipping up the waves it's a tough task but if the first cylinder can be successfully positioned it will be a good start to build the island typhoon is approaching and all ships have been ordered by maritime officials to seek safe harbor [Music] things finally start going more smoothly at the site of the east island the cylinder begins to sink faster indicating that it has passed through the hard layer 10 minutes later the cylinder has reached the designated depth workers immediately examined the hammer for signs of damage but it appears to be all right [Music] all the ships have found safe harbor phase one of construction at the east island smoothly ends prior to the arrival of nessat following 28 years of preparation chinese engineers have finally begun to construct this world's longest cross-sea bridge over the busiest sea area in the world they have made large steel cylinders to form two artificial islands produced 33 tunnel sections each as large as an aircraft carrier for the world's longest undersea tunnel they build the world's longest steel bridge in spite of the complex seabed and harsh natural conditions but it's just a beginning and the project is far from over in the upcoming four years there will be more limits to challenge and more world records to break in four years hong kong will be able to quicken its developing pace while the young people in macau will have greater expectations in juhai meanwhile those creative kids will grow up as well facing a more extensive world by then the hong kong juhai macau bridge will tell more stories of chinese engineers as to how they have challenged new limits and finished the new mega project [Music] [Music] you

Channel: Free Documentary

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Keywords: Free Documentary, Documentaries, Full documentary, HD documentary, documentary - topic, documentary (tv genre), HZMB, engineering, engineering documentary, construction, construction documentary, worlds longest bridge, long bridge, china mega project, mega project, china construction, Hong Kong-Zhuhai-Macao Bridge, bridge engineering, bridge documentary

Id: q_et-GQQiKw

Length: 48min 44sec (2924 seconds)

Published: Fri Oct 01 2021