What are the difficulties in the construction of the Hong Kong-Zhuhai-Macao Bridge?

1,120m Hong Kong-Zhuhai-Macao Bridge crosses Dingling Ocean at the Pearl River Estuary, connecting Hong Kong, Zhuhai and Macau. Due to the high navigation requirements of Dingling West Channel and Tonggu Channel, the navigation capacity of 300,000-ton cruise ships should be guaranteed for a long time. However, in order to meet the navigation capacity of a 300,000-ton cruise ship, it is necessary to build a super bridge with a deck height of more than 80 meters and a tower height of 200 meters. However, the height limit of Lantau Airport fairway is120m. Therefore, it is impossible to use the bridge scheme to cross these two waterways. If we can't find a solution, the Hong Kong-Zhuhai-Macao Bridge will fall into endless difficulties. In this regard, our countermeasure is to build a cross-harbour tunnel. Due to the height limitation, the cross-harbour tunnel can not only solve the water crossing problem, but also greatly reduce the impact on the surrounding environment and solve the shipping problem in large areas of water. Especially with the continuous breakthrough of some key technologies in the construction of cross-harbour tunnel, cross-harbour tunnel has gradually become the first choice generally recognized by the engineering community to cross busy shipping channels. Therefore, the reason why the Hong Kong-Zhuhai-Macao Bridge chose to build a long cross-harbour tunnel and become the longest cross-sea bridge in the cross-harbour tunnel is restricted by objective factors. On the other hand, it is also because the cross-harbour tunnel has its own unique advantages. 2, 10% water resistance To build a submarine tunnel, we must first find an island that can connect the bridge and the submarine tunnel. Because there are no ready-made islands in the nearby waters, it is necessary to build artificial islands to connect the submarine tunnels and bridges. Lingdingyang is a typical weak ocean current area, and a large amount of sediment flows into Lingdingyang from the Pearl River Estuary every year. If the length and width of the artificial island are too large, it will prevent sediment from flowing into the sea. Once the water blocking rate exceeds 65,438+00%, sediment may block the deposition and turn the Lingdingyang into an alluvial plain in the passage of time. In order to avoid such disastrous consequences, it is necessary to reduce the area of the artificial island and control its length within 1 km. However, if the shield method is adopted, the length of the artificial island will eventually exceed the standard and touch the 10% waterproof red line because the shield method requires high stability and the tunnel is buried deeply. Considering the water blocking rate, tunnel scale and hydrogeological conditions in the sea area, the immersed tube method is finally used instead of the shield method. Immersed pipe tunnel refers to shallow excavation of trench on the seabed, sinking prefabricated pipeline into trench, and then underwater docking. After adopting immersed tube tunnel technology, the island length of 400 meters is reduced and the island length is controlled at 625 meters, which solves the problem of 10% water resistance.

Before 38 million cubic meters of silt, it was mentioned that a 625-meter-long artificial island should be built to connect the bridge and the cross-harbour tunnel. However, there is a layer of silt 15 to 20 meters at the place where the artificial island is built. Due to the physical properties of silt, if a riprap slope or a traditional gravity caisson is built on it, the riprap or gravity caisson will slide due to silt and the foundation will be unstable. The most conventional way is to clean up all the silt, or dry it by drainage and consolidation, and then throw stones or sit steadily with caissons. However, it is unrealistic to dry sludge by draining water from the seabed. If we want to clean up all the silt, we need 8 million cubic meters of silt, which is not only time-consuming and laborious, but also causes great pollution to the marine environment. In this regard, the engineer's solution is to use 120 circular steel cylinder, weighing 550 tons, 55 meters high and 22.5 meters in diameter to form a circle to stabilize the foundation. The steel cylinder will be inserted into silty clay and silty clay sand layer, and gradually form a stable structure. At that time, as long as sand is filled in the artificial island surrounded by steel drums, steel drums will leave sand in the artificial island, so there is no need to worry about riprap and caisson behind. 4. The premise of successfully building an artificial island with an error of 3 cm is to make 120 a giant steel drum with a weight of 550 tons and a height of 55 meters. However, due to the huge volume of the steel drum, no bending machine or die can complete the manufacturing work of this steel drum, and the steel drum must be assembled into 72 modules in groups. However, this practice will also bring a problem. Because the error of steel drum is limited to 3 cm, and there will be some errors in each splicing, and the number of spliced modules reaches 72, the huge volume of steel drum up to 55 meters is very unfavorable for processing and manufacturing, and the error may not be controlled within 3 cm after repeated splicing. Finally, the engineer solved the accuracy problem of steel drum manufacturing by using the inner container-manufacturing a steel structure bracket that can control the shape of the cylindrical steel drum, and splicing the steel structure bracket with assistance, and finally controlling the error within 3 cm. 5. The floating of immersed tubes and the submarine tunnel of Zhuhai-Macao Bridge in Xiachenxiang Port are formed by butting 33 immersed tubes with reinforced concrete structure. Each standard immersed tube has a length of180m, a width of 38m, a height of11.4m and a displacement of about 80,000 tons. After the tunnel immersed tube is prefabricated on the shore, both ends are sealed with steel sealing doors. The immersed tube floats on the sea surface, is towed to the construction sea area about 7 nautical miles away by several high-power tugboats, and then sinks into the seabed for docking installation. Due to the huge volume and heavy weight of immersed tube, limited by hydrological conditions and channel width, and the high precision requirement during immersed tube, immersed tube floating is an important technology in the construction process. The influence of towing force, velocity and direction, tide, seawater density and strong wind should be considered in immersed tube floating. Due to the influence of water resistance coefficient and other factors, the calculated results of empirical formula will be different from the actual results. If the calculation of towing force is not accurate, the cable may break and the immersed tube may overturn. In addition, tides can also cause changes in water level, and the density of seawater can also cause changes in buoyancy. The size and direction of water flow are important factors that determine the size of pipe joints and the way of floating and sinking, which need to be carefully considered. There are also many technical challenges in immersed tube sinking. Because the local construction area belongs to extremely soft and diverse soil, it is easy to cause excessive settlement. In this case, the installation will seriously affect the installation accuracy, and the error cannot be controlled within 7 cm as required, which may bring incalculable consequences to the engineering quality of the tunnel. In addition, there is a high requirement for stability in the process of pipe sinking, and the siltation of submarine foundation trench will also bring great obstacles to pipe sinking ... Faced with the above challenges, engineers take measures to solve the problems one by one. In order to determine the towing force, engineers carry out drag resistance model tests of pipelines to determine the drag resistance of pipelines and pipeline components, and calculate the towing force and the number and required power of tugboats according to the test data. In order to avoid excessive settlement and ensure the installation accuracy, before each immersed tube is installed, a submarine tunnel foundation trench is excavated at the seabed more than 40 meters deep in Lingdingyang. After the trench is dug, sand piles are pressed, and then 2-3 meters of stones are laid on the foundation trench and rammed flat, creating a new composite foundation, which greatly reduces the settlement value of the immersed tube, and the error is controlled at about 5 cm. In the face of the sludge backflow of submarine foundation trench, on the one hand, five fixed observation points are set to keep the sediment detection in the construction sea area, provide effective early warning analysis of sediment deposition, and provide reliable guarantee for the subsequent immersed tube installation and construction. On the other hand, an underwater transverse silt retaining dam is set up to intercept the silt flowing back along the direction of the foundation trench, and at the same time, the dredgers Jielong and Junhai No.6 are mobilized to clean up the silt. 143589 trample

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High-energy answer 202 1-08- 16 Excellent signature highlights my personal consultation concern. Thank you for your concern. The difficulty in the construction of Hong Kong-Zhuhai-Macao Bridge is the complicated meteorological and hydrological conditions. The Hong Kong-Zhuhai-Macao Bridge is located in the open sea, with complex meteorological and hydrological conditions and great difficulty in HSE management. Lingdingyang is located at the mouth of the Pearl River. The turbulent undercurrent at ordinary times and the annual typhoon in the South China Sea have great influence on bridge and tunnel construction, which is difficult and accurate. The seabed soft foundation is deep, that is, the muddy soil and silty clay on the seabed where the project is located are deep, and the underlying bedrock surface fluctuates greatly. The buried depth of bedrock is 50 ~ 1 10 meter, which has corrosive effect on conventional reinforced concrete bridge structures. Lingdingyang is a weak current sea area, and a large amount of silt is not only easy to accumulate and block the navigation channel and form an impact plain when new docks, artificial islands or tunnels are excavated by shield technology, but also interfere with the filling of artificial islands and the placement and docking of prefabricated immersed pipes. At the same time, silt is an important part of the ecological environment, and excessive excavation will cause disastrous damage. Significance: The completion and opening of the Hong Kong-Zhuhai-Macao Bridge is beneficial to ...

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Seo-hee Jang 0012014-11-29ta has won more than 64,000 likes. Thank you for your attention. One is the problem of funds, the other is the technical problem, and the third is the communication problem: the funds are huge, and all three parties have to pay part. How to allocate funds is a big problem; Seeing the cross-harbour tunnel has always been a technical problem, which goes without saying; A bridge connects three places, which requires frequent communication between the three places and is more troublesome. If you are satisfied with the answer, please adopt it and encourage enthusiastic people. It is not easy to help others these days ~ ~ ~ ...

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2022-02- 16

Travel advice for you who come to Zhuhai-Macao Bridge for the first time.

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What problems did the builders encounter during the construction of the Hong Kong-Zhuhai-Macao Bridge? 2 Zan 1 Broadcast What are the unfavorable natural factors during the construction of the Hong Kong-Zhuhai-Macao Bridge? The Hong Kong-Zhuhai-Macao Bridge is located in the open sea, with complex meteorological and hydrological conditions and difficult construction. 1, Lingdingyang is located at the mouth of the Pearl River. The usual surge and undercurrent and the annual typhoon in the South China Sea have great influence on bridge and tunnel construction, which is difficult and accurate. The seabed soft foundation is deep, that is, the muddy soil and silty clay on the seabed where the project is located are deep, and the underlying bedrock surface fluctuates greatly, and the bedrock is basically buried within 50 ~ 1 10 meters; Seawater chloride will corrode the traditional reinforced concrete bridge structure. 2. Lingdingyang is a weak current sea area, and there is a large amount of landscape silt on the surface of Qingzhou Waterway Bridge of Hong Kong-Zhuhai-Macao Bridge. In the process of tunnel excavation by new pier, artificial island or shield technology, it is not only easy to accumulate and block the waterway, but also interfere with the artificial island filling and the placement and docking of prefabricated immersed tubes. At the same time, silt is an important part of the ecological environment, and transitional excavation will cause disastrous damage; Therefore, the bridge and tunnel project should not only meet the stringent requirements of water resistance below 10%, but also not excessively transport mud. 3. The main project of the Hong Kong-Zhuhai-Macao Bridge goes deep into the open sea, and at the same time, it has to face the complicated and changeable marine climate and seabed geological conditions, and there are unfavorable factors such as deep water depth, large runoff and strong siltation. 20 15 Hong Kong-Zhuhai-Macao Bridge immersed tube tunnel placement and docking experience failed many times. Among them, the immersed tube of E 15 section floated up three times and returned twice, for a total of 156 days, and the installation was completed. Extended data:

1. The Hong Kong-Zhuhai-Macao Bridge crosses the core area of China White Dolphin Nature Reserve for about 9 kilometers, with a buffer zone of about 5.5 kilometers, covering a total sea area of about 29 square kilometers. In order to achieve the goal of no dolphin migration and zero casualties, the construction unit has made several adjustments to the design and construction scheme of the bridge, such as reducing the number of piers from 3 18 to 224; Try to avoid large-scale dredging, excavation and other operations that are easy to produce a large number of suspended solids during the peak breeding period of white dolphins from April to August; Adjust the angle between the main line of the bridge site and the direction of water flow, reduce the dumping amount of dredged materials and reduce the adverse impact of the project on marine hydrodynamic and biological resources. 2.20 18 In June, according to Guangdong Marine Environment Bulletin issued by Guangdong Provincial Department of Ocean and Fisheries, the Pearl River Mouth Chinese White Dolphin National Nature Reserve Administration witnessed 380 Chinese white dolphins on 20 180 occasions. According to the latest data of 20 17, 234 Chinese white dolphins living in the Pearl River Estuary have been added to the database, and 2367 dolphins have been identified. The cost of protecting white dolphins reached 340 million yuan. Baidu Encyclopedia-Hong Kong-Zhuhai-Macao Bridge Baidu Encyclopedia-Lingdingyang 60 likes 5308 Browse 20 19-06- 10

What are the main natural obstacles considered in the construction of the Hong Kong-Zhuhai-Macao Bridge? The bridge is located in the open sea, with complex meteorological and hydrological conditions and difficult construction. 1, Lingdingyang is located at the mouth of the Pearl River. The usual surge and undercurrent and the annual typhoon in the South China Sea have great influence on bridge and tunnel construction, which is difficult and accurate. The seabed soft foundation is deep, that is, the muddy soil and silty clay on the seabed where the project is located are deep, and the underlying bedrock surface fluctuates greatly, and the bedrock is basically buried within 50 ~ 1 10 meters; Seawater chloride will corrode the traditional reinforced concrete bridge structure. 2. Lingdingyang is a weak current sea area, and there is a large amount of landscape silt on the surface of Qingzhou Waterway Bridge of Hong Kong-Zhuhai-Macao Bridge. In the process of tunnel excavation by new pier, artificial island or shield technology, it is not only easy to accumulate and block the waterway, but also interfere with the artificial island filling and the placement and docking of prefabricated immersed tubes. At the same time, silt is an important part of the ecological environment, and transitional excavation will cause disastrous damage; Therefore, the bridge and tunnel project should not only meet the stringent requirements of water resistance below 10%, but also not excessively transport mud. 3. The main project of the Hong Kong-Zhuhai-Macao Bridge goes deep into the open sea, and at the same time, it has to face the complicated and changeable marine climate and seabed geological conditions, and there are unfavorable factors such as deep water depth, large runoff and strong siltation. 20 15 Hong Kong-Zhuhai-Macao Bridge immersed tube tunnel placement and docking experience failed many times. Among them, the immersed tube of E 15 section floated up three times and returned twice, for a total of 156 days, and the installation was completed. Extended data:

The Hong Kong-Zhuhai-Macao Bridge connects Lantau Island in Hong Kong, Macao Peninsula and Zhuhai City in Guangdong Province. As a cross-sea bridge project with the longest mileage, the largest investment and the most difficult construction in China's construction history, the Hong Kong-Zhuhai-Macao Bridge has attracted much attention since it was started in 2009. The planned 29-kilometer-long bridge is expected to cost US$ 2 billion, or about RMB 654.38+02.73 billion. When completed, it will become the fourth bridge in the world after Pontchartrain Lake Bridge, Ningbo Hangzhou Bay Bridge and Jiaozhou Bay Bridge. After it is completed and opened to traffic, it is expected that the time from Hong Kong to Zhuhai will be greatly shortened from more than three hours to more than half an hour. 7,643 experts answered in 5 minutes | 10,000 professionals answered what is the main building structure of the Hong Kong-Zhuhai-Macao Bridge? The Hong Kong-Zhuhai-Macao Bridge consists of three navigable bridges, a submarine tunnel, four artificial islands and connecting bridges and tunnels, a continuous beam bridge with navigable holes in deep and shallow waters, and land connections between Hong Kong, Zhuhai and Macao. Among them, the three navigable bridges are Qingzhou Waterway Bridge, Jianghai Direct Ship Waterway Bridge and Jiuzhou Waterway Bridge from east to west. The Cross-Harbour Tunnel is located between Lantau Island in Hong Kong and Qingzhou Waterway Bridge, connecting other bridge sections through artificial islands on the east and west sides. Continuous beam bridges with navigable holes in deep water area and shallow water area are located in the waters near Hong Kong and Zhuhai respectively. The three ports and their artificial islands are located near the approach bridges at both ends and connected with the surrounding main roads through connecting lines. Design parameters of Hong Kong-Zhuhai-Macao Bridge: The total length of the Hong Kong-Zhuhai-Macao Bridge is about 55 kilometers, including 4 1.6 kilometers from Zhuhai-Macao Port to Hong Kong Port, and the total length of the sea-crossing section is 35.578 kilometers. The main works of the three places are 29.6 kilometers, including 6.7 kilometers of submarine tunnels and 22.9 kilometers of bridges; 224 piers and 7 pylons; The bridge width is 33. 1m, the immersed tunnel length is 5664m, the width is 28.5m, and the clear height is 5.1m; The maximum longitudinal slope of the bridge deck is 3%, the transverse slope of the bridge deck is within 2.5%, and the transverse slope of the tunnel pavement is within 65438 0.5%; The bridge deck is constructed according to the standard of two-way six-lane expressway, with a design speed of 100 km/h and a total pavement area of 700,000 square meters. Navigable bridges and tunnels can meet the needs of oil tankers, with a short-term capacity of 654.38 million tons and a long-term capacity of 300,000 tons; The designed service life of the bridge is 1.20 years, and it can resist earthquakes with magnitude of 8, typhoons with magnitude of 1.6, 300,000-ton shocks and the once-in-a-century Hong Chao in the Pearl River Estuary.