The Han River in our country is actually almost like a lake There's a large sandy beach near Ttukseom, and the landscape of the Han River is designed with matching heights and roads built like embankments The width of the Han River has been expanded to 1km But the biggest reason for this is that... [Music] Yes! Hello, Watsons This time, we're planning to do a special segment on the bridges of the Han River The production team will do some research, and I'll add what I know to have a discussion with you guys First of all, there are a total of 31 bridges over the Han River The Han River doesn't just flow through Seoul It stretches from the Paldang Dam to Gimpo, so out of the 31 bridges, 22 are located within Seoul These 22 bridges facilitate traffic between the northern and southern parts of the city We'll first look into which of these 22 bridges in Seoul has the highest traffic volume The busiest is the Hannam Bridge, with a daily traffic volume of about 180,000 vehicles That's a huge number Originally, the Hannam Bridge was the third bridge to be built over the Han River, initially known as the Third Han River Bridge Due to increased traffic, the road was expanded into two parts, making it a 12-lane bridge from a 6-lane one The importance of the Hannam Bridge comes from its connection to the Gyeongbu Expressway, which is the main diagonal artery across South Korea, and its Expressway number is 1 Starting in Busan and ending in Seoul, the Gyeongbu Expressway's terminus is at the Hannam Bridge And the Hannam Bridge leads directly to Gwanghwamun via the Namsan 1 Tunnel, which explains its high traffic volume So, there must be a lot of traffic going on that bridge I've heard real estate experts say that when buying property, you should always focus on the area within a certain radius centered on Hannam Bridge As they are seeing tis region as the center of the capital, Seoul According to my research, the bridge with the highest traffic volume in the world is the George Washington Bridge, connecting Manhattan and New Jersey It's a double-decked suspension bridge This bridge leads to New Jersey, and from there, it marks the start of the cross-continental highways that span from east to west across the United States Following this route takes you through Chicago, Indiana, and all the way to the West Coast This route, with daily traffic of 250,000 vehicles, is the busiest in the world What's unique about the New Jersey side, known as the Palisades, is its cliffs There's a car named after it, the Hyundai Palisade, which is quite majestic The terrain suddenly drops off at a significant height It is quite high Manhattan's north is also rocky terrain, making it the connecting point between the two This means that if a bridge like the Hannam Bridge, with typical pillars, were to be built from the top of the Palisades, which is much higher than the water level, it would have to be incredibly tall If we build pillars of such height would result in excessive construction costs So, to solve this, they adopted a suspension bridge design for the George Washington Bridge They erected two towers and hung the cables between them to construct the bridge Another bridge built on the same principle is the Brooklyn Bridge, which connects Manhattan and Brooklyn A common feature of these bridges is that they span over waters with significant depth Both the Hudson and East Rivers meet the ocean, making their depths considerable This means they are suitable harbors for large ships The Hudson River, for instance, accommodates some of the world's largest passenger ships To give you an idea, some of these ships, when docked, are about the height of a 20-story building One day, while driving, I thought a new building had been constructed, only to find out it was actually one of the world's largest passenger ships docked at the time The depth that allows such large ships to dock means that it's impossible to build a bridge with piers like those on the Han River in such deep waters Alternatively, tunnels are constructed, such as the Lincoln Tunnel that cuts through the middle of Manhattan, and below it, the Holland Tunnel. Bridges over such spans are made as suspension bridges, like the George Washington Bridge What makes suspension bridges fascinating is how their cables hang down When you're driving across, especially during foggy conditions common around river estuaries, the bridge presents a profound sense of space It's not just any bridge; because it's a suspension bridge, the number of visible cables changes with the fog—sometimes you see about 100 cables, other times 50, or 70 This variability alters the perception of depth and space It becomes a reference point for the depth of space, making it a truly remarkable design feature of the bridge That's how I remember Next up, with the second highest traffic volume, is the Seongsan Bridge It connects Mangwon-dong and Yangpyeong-dong, spanning a total length of 1.4 km and featuring six lanes in both directions The daily average traffic volume here is reported to be 150,000 vehicles That's also outrageous This bridge is generally appreciated for its aesthetic, partially due to its steel truss structure with piers supporting semi-circular arches or crescent-shaped structural forms It's recognized for its architectural beauty On the third place, it's Yanghwa Bridge It connects Hapjeong-dong and Yangpyeong-dong, spanning 1 km with eight lanes in both directions, and sees an average daily traffic of 140,000 vehicles This bridge is famous for a couple of reasons First, It goes through Seonyudo Park, and it's known from the song "Yanghwa BRDG" by Zion.T, which made it quite popular Additionally, Yanghwa Bridge gained attention during the "Han River Renaissance" project, which involved the creation of the Gyeongin Canal to allow passenger ships from China to travel through the Han River to the International Business District However, the bridge is relatively low and has narrow pillar spacing, which restricts large ships from passing There was a plan to widen the gaps between the pillars and modify the bridge to accommodate larger vessels, but these plans were shelved after a change in the city's administration Now, the bridge has only been repaired, nothing else Ah! Seonyudo Park is definitely a place that everyone should visit once About 20 years ago, architects in South Korea voted on their favorite architectural work, and Seonyudo Park was selected Originally, it was a site for water purification facilities, an industrial facility that was no longer in use Later, it was transformed into a park It was beautifully done Industrial structures, for example, had their roofs removed, leaving only the supporting pillars, under which ivy was grown, creating what's known as a "garden of green pillars." Ivy grows up around them, and some concrete pillars are left as they are, allowing visitors to feel the passage of time through these elements These techniques minimally intervene with the original industrial structures, converting them into beautiful ponds or landscapes The park, designed by architect Cho Sung-ryong, is truly remarkable It's a place I recommend visiting Among the various types of bridges over the Han River, girder bridges are the most common To say it simple, these bridges consist of concrete piers supporting girders that span across them Hannam Bridge is a typical example of a girder bridge, which is the prevalent design for most bridges across the river This design is feasible primarily because the water level of the Han River is not very high Understanding the Han River requires acknowledging a fundamental fact: the Han River is almost more akin to a lake than a typical river The Han River's width was actually very narrow, almost like a dry riverbed, only significantly swelling during the rainy season Outside of these periods, as it doesn't rain a lot, the river's width was very narrow The modern expanse of the Han River, averaging about 1km in width, differs greatly from its original state, which was only a few hundred meters wide, with the remainder being sandy beaches Especially before the construction of the Paldang Dam, all the sediment from the Gangwon Province would flow down, leading to the accumulation of sandbanks alongside the river whenever it flooded and then receded These sands have largely disappeared due to a river management project undertaken for the 1988 Olympics The project aimed to prevent sewage from entering the Han River directly, involving the construction of a separate sewage system and the creation of underwater weirs to control the river's flow and improve its overall condition In Jamsil, there's an underwater weir, and another is located beneath the Gimpo Bridge The existence of these two weirs essentially means that a kind of wall has been created The maximum height of the weir under the Gimpo Bridge ensures that the Han River maintains a consistent level all the way to Jamsil Then, there's a difference in height again So, if you look at the Jamsil Bridge from the side, you'll notice a section where the water appears to fall like a waterfall This is due to the underwater weir What this means is that the sediment flow from the Paldang Dam was initially halted Then, with the water flow being obstructed once by the dam and again by the weir, the Han River could no longer form sandbanks as it once did The extensive sands that were there settled under the water due to the construction of the weirs And where did all that sand go? It was dredged up and used in the construction of apartments Though it's no longer visible, there used to be massive piles of sand along the riverbank in Jamsil That sand went into building the apartments in Jamsil and Gangnam River sand is actually considered the best type of sand for construction because it doesn't contain salt, making it significantly more expensive than ordinary sand However, by the time Ilsan and Bundang new cities were being developed, the supply of Han River sand had been depleted Consequently, sand was dredged from the sea, which contains a higher salt content This could potentially weaken the strength of the cement, a concern that was once prominently featured in the news Fortunately, decades have passed without major incidents, indicating no significant problems have arisen from this The Han River's landscape was once characterized by large sandy beaches, similar to Ttukseom, where the river's width expanded to 1km The primary reason for this transformation relates to the river's tendency to flood annually during the rainy season, with water levels rising between 8m to 12m This necessitates the presence of embankments to prevent overflow; otherwise, areas like Pungnap-dong or Goyang city would frequently flood The construction of dams, leading to what we now see as Olympic-daero, was implemented to address this issue The construction along the northern bank of the Han River, such as the Gangbyeonbuk-ro, acts like an embankment By creating two underwater weirs, the height was regulated, leading to the widening of the river As a result, bridges over the Han River are built higher than the roads like Olympic-daero and Gangbyeonbuk-ro That is how this structure was developed The most common construction technique used for these bridges was the girder bridge, which involves placing girders on top of piers You can see it in that Another notable type is the truss bridge, famously exemplified by the Han River Railway Bridge If you look at it, the parts painted green are under compression, and those in red are under tension, supporting the pulling forces Intuitively, consider how a truss structure behaves: if a bridge sags, the bottom part stretches, creating tension, while the top part compresses Truss structures are typically made of steel, a material strong in both compression and tension A well-known example is the Seongsu Bridge, infamous for its collapse in 1994 I remember it too There was an incident where a bridge deck just collapsed while I was in Boston Next up is the cable-stayed bridge In South Korea, the Olympic Bridge is an example of a cable-stayed bridge It features two main towers, and as you can see, cables extend downward to support the bridge deck This differs from a suspension bridge The key difference between a cable-stayed bridge and a suspension bridge is that in a cable-stayed bridge, the cables directly connect the towers to the bridge deck In contrast, a suspension bridge uses a main cable, suspended between towers, from which vertical cables hang to support the deck So, the Golden Gate Bridge is a suspension bridge, while the Olympic Bridge is a cable-stayed bridge You can see it in that way I personally think the Olympic Bridge is a beautifully designed bridge Indeed, the Olympic Bridge is one of the bridges over the Han River that is unique Which bridge would be tallest and longest? The longest bridge over the Han River is the Magok Bridge, which is used by the Airport Railroad and spans an impressive 2.9 km So it does not only go across Han river, it goes over that This length (2.9km) surpasses that of the Golden Gate Bridge, which is 2.7 km The world's longest bridge, it's the Danyang–Kunshan Grand Bridge It is located between Shanghai and Nanjing for the high-speed railway, stretching about 164 km This is more akin to an elevated road than a mere bridge And in terms of height, the highest bridge over the Han River is the World Cup Bridge, with a height of 100m at its main tower This means that its pylon's height is 100m World's tallest bridge Wow..I also saw this picture This is called the Millau Viaduct, designed by Norman Foster, with a staggering height of 342m and a total length of 2.4 km Norman Foster earns his reputation and income through such monumental projects I've had some experience designing a pedestrian overpass myself, and from what I've seen, the architectural design fees can be about ten times the norm for projects of significant scale and complexity Indeed, it seems like construction costs always have a couple more zeros attached to them, especially in civil engineering Norman Foster, known for undertaking colossal projects like bridges and airports, maintains a workforce of over a thousand employees, thanks to these large-scale projects It was astonishing to hear that Foster participated in the Seoripul design competition, presenting a proposal I heard that he really put a lot of effort into it We ended up in the same position—both not selected, haha There are two renowned architects known for designing bridges: Norman Foster and Santiago Calatrava Calatrava originally comes from a civil engineering background, which explains his extensive work on bridges and overpasses Now, he's fully transitioned to architecture, taking on airports, train stations, and even apartment buildings However, when designing, it seems his work often emphasizes structural beauty, aiming for a sense of proportion and a more refined aesthetic Indeed, there's another famous bridge known as the Millennium Bridge There are actually two bridges named the Millennium Bridge In London, there's one designed by Norman Foster, and then, arguably more impressive, is another Millennium Bridge located in the north of England This bridge features an arch from which cables extend down to support the deck What makes this bridge fascinating is its ability to tilt several times a day to allow boats to pass underneath It's a brilliant design with pivot axes on both sides The arch tilts in one direction while the bridge curves in another By pulling on this arrangement, the bridge is designed to collapse towards one side and the arch towards the other, achieving a balance between the two masses In this state, the arch can rotate the bridge with just a light force, much like a seesaw, creating a remarkable structure That bridge left a lasting impression on me Norman Foster is associated with a famous anecdote related to his work on significant projects in the UK for the year 2000 Among these were the London Eye and the Millennium Bridge, with Richard Rogers undertaking the Millennium Dome The Millennium Bridge, designed as a pedestrian-only crossing, connects St. Paul's Cathedral, a historic site in London's old city, with Tate Modern, which was repurposed from a former power station into an art gallery, revitalizing the area The bridge, created to link these two landmarks, encountered an unexpected issue upon completion Really surprising fact is that the structural engineering was done by ARUP, known globally for their expertise in designing seemingly impossible structures, including the CCTV headquarters When you question, "How is that built?", then it's normally constructed by ARUP However, when the bridge opened, it exhibited unexpected swaying This was surprising because ARUP had meticulously calculated the structure's requirements, yet the bridge still oscillated The reason for this swaying differed from typical bridge dynamics, primarily designed for vehicular traffic, where the load is consistently downward due to the rolling of wheels even with 1 ton truck In contrast, pedestrian movement is different When children learn to walk, the process they undergo illustrates how humans naturally balance their weight between left and right steps While stepping forward with the left foot, our center of gravity shifts slightly to the right, and vice versa, leading us to push off from each foot in turn, akin to skating This concept of synchronization, or "sync," is a key theme in the book <Sync> by Steven Strogatz which discusses how synchronization is a fundamental trait of life 시간을 딱 맞추는 거 An example mentioned in the book involves hundreds of thousands of fireflies in Southeast Asia that flash their lights in perfect unison, without any apparent communication or telepathy, highlighting how living beings naturally synchronize The book also delves into the human heart's rhythmic pulsing As heart is beating, it creates pulse The heart, with its modest electrical output measured in mere watts or volts, relies on the synchronized pulses of all cardiac cells to generate electrical signals This synchronization allows the heart to contract and pump blood, sustaining life This principle of synchronization, or being in sync, is presented as a fundamental aspect of life The Millennium Bridge serves as a notable example in discussions about synchronization When the millenium bridge is opened, thousands of people will be walking across it simultaneously, isn't it? When a person walk, he or she will walk left and right Unknowingly, people began to match their steps with the bridge's vibrations, amplifying the movement When 10, 20, 100, 1000 people starts to sync their steps, this synchronization among pedestrians led to movements from an initial 0.1mm to significant oscillations of several centimeters Had this synchronization continued unchecked, it could have potentially led to structural failure The cause of this sway wasn't immediately understood, leading to the bridge's temporary closure on its opening day And they started to research about it The solution that they found was really simple By installing lateral dampers beneath the bridge, engineers could counteract the sway by pulling in the opposite direction of the bridge's movement So they have installed things like buffer underneathe it and solved this problem It's very interesting From this, we see that the fundamental principles of life, starting with how living beings synchronize their movements, contrasted with the movement of cars, all came together in the incident with the Millennium Bridge Banpo Bridge, it's a favorite of mine It's situated above the Jamsu Bridge, spanning 795 meters, with an additional section of Banpo Bridge extending 1.5 km One of my most memorable experiences there was a Louis Vuitton fashion show held on the bridge I really felt that Louis Vuitton understood the context of Seoul well Fashion shows require a linear space, where models walk down a straight path, turn around, and come back—a simple movement that needs a dramatic setting to shine I think that Jamsu Bridge was an ideal location for this Models started their walk from the slope, making their way across the bridge under a roof The only downside was the weather, which turned unexpectedly cold that day Other than that, it was a perfect show, especially with the Rainbow Fountain's finale adding a spectacular touch (Point1. A bridge that Sherlock HyunJoon wants to build) The thing that I've been kept emphasizing was the cultural differences between Gangnam and Gangbuk, attributing the divide to the necessity of crossing the Han River by car or subway So I wish for things that allow us to cross the river leisurely and comfortably, as the proximity to speeding cars discourages from walking Therefore, I thought it would be great to have a pedestrian-only bridges, especially those that link Gangnam and Gangbuk, as it is quite lengthy, people will only go across the bridge when there is attraction on the opposite side It would encourage people to cross the bridge more often as both regions have completely different context Seoul Forest stands out as a prime attraction in Gangbuk, offering green space that's rare in Seoul Meanwhile, Gangnam's Rodeo and Apgujeong areas serve as attractions on the other side As this Rodeo and Apgujeong areas are places where most Seoul residents prefer, whether they are from Gangnam or Gangbuk, thus, I've always thought a pedestrian bridge connecting these points would be highly beneficial This presents a great opportunity, as the area from Banpo to Jamsil is undergoing apartment complex reconstructions, requiring developers to make contributions either in land or facilities Imagine if, during these redevelopments, a portion of the contributions from apartment complexes could be allocated towards creating pedestrian-only bridges across the Han River It would serve as a win-win scenario So the general public gains new, convenient routes to cross the river on foot And for the developers, making such a contribution by funding a pedestrian bridge could significantly increase the attractiveness and value of their apartment complexes In my role as the master architect for the (former) Hyundai Apartment project, I proposed utilizing these contributions to establish a direct, walkable path from Apgujeong Station on Line 3 to Seoul Forest Then it could be a win-win scenario for them both So, that's why I'm making this proposal, hoping earnestly that it gets implemented (Point2. Center of Seoul) The Han River, when viewed on a global scale, arguably plays a more crucial role in shaping Seoul's identity than any other river could, thanks to its wide expanse and the surrounding mountains that define the city's landscape With features like Namsan and the river's meandering course, traveling along the Han River by car or on foot offers an ever-changing view, with different landscapes emerging around every bend For instance, near Jamsil Bridge, you encounter Acha Mountain, and as you move towards Hannam Bridge, Namsan becomes the backdrop, with Eungbong Mountain near Seongsu Bridge So there are lots of mountains surrounding the river This diverse topography surrounding the river adds a dynamic vibrancy to Seoul that few cities worldwide can match I believe it's essential to leverage this dynamism effectively As numerous apartment complexes undergo redevelopment, there's an opportunity for a give-and-take with Seoul City, allowing for beneficial exchanges that enhance access to these scenic riverfront views I hope such negotiations progress smoothly This concludes our discussion on Seoul and the Han River See you guys next time Source : Gettyimages korea
