350 km/h Fuzhou-Xiamen high-speed rail through the mountains and across the sea
2023-09-14 09:18:08 Source: Fujian Daily
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350 km/h Fuzhou-Xiamen high-speed rail through the mountains and across the sea
A test train of Fuzhou-Xiamen high-speed railway runs on the Quanzhou Bay cross-sea Bridge in east China's Fujian province, Aug. 31, 2019. Photo by Reporter Lin Hui and correspondent Ding Bo
350 km/h Fuzhou-Xiamen high-speed rail through the mountains and across the sea
A large area of weather-sensing intelligent skylight is installed on the roof of the newly built transfer center of Xiamen North Railway Station, reflecting the concept of wisdom and energy saving. Reporter Lin Hui
350 km/h Fuzhou-Xiamen high-speed rail through the mountains and across the sea
New Xiamen North Railway Station smart monitoring room. Photo by Lin Hui
350 km/h Fuzhou-Xiamen high-speed rail through the mountains and across the sea
From a high altitude, the new Xiamen North Railway Station looks like a surging wave on the sea. Photo by Lin Hui
350 km/h Fuzhou-Xiamen high-speed rail through the mountains and across the sea
Overlooking Quanzhou Bay cross-sea bridge.
350 km/h Fuzhou-Xiamen high-speed rail through the mountains and across the sea
Panoramic view of Meizhou Bay Sea Bridge.
Core tip
After more than six years of construction, the country's first cross-sea high-speed rail with a design speed of 350 kilometers per hour - Fu-Xiamen high-speed rail has the conditions for opening within the year, and "watching the sea while sitting on high-speed rail" is about to come into reality.
With a total length of 277.42 kilometers, it has crossed three cross-sea Bridges in Meizhou Bay, Quanzhou Bay and An Bay, with a crossing length of 19.9 kilometers on the sea. There are 84 main line Bridges and 29 tunnels, and the bridge-tunnel ratio is as high as 85.1%. A large number of digital simulation, intelligent construction, intelligent sensing, intelligent analysis and other technologies are used. The construction of Fuzhou-Xiamen high-speed railway is an integrated application of the latest scientific and technological achievements of intelligent high-speed railway in China. In terms of Bridges, tunnels, station buildings, etc., the design and construction units have completed a total of 91 model projects with representative significance, filling a number of gaps in the field of high-speed rail construction.
The Fuzhou-Xiamen high-speed railway has opened a new chapter in the construction of smart high-speed railways in China's coastal areas.
Under the 11 storm, the traffic of the cross-sea bridge is not closed; Only the fiber optic lighting system of the newly built Xiamen North Railway Station can save about 720,000 KWH of electricity every year; The "digital twin" technology connects the virtual and reality of high-speed rail... This in-depth reading focuses on the science and technology behind the Fuzhou-Xiamen high-speed rail crossing the mountains and the sea.
Seismic isolation technology, even if the wind is strong
The new design allows the bridge to bypass the wind direction, reducing wind-induced vibration in complex wind environments, allowing the bullet train to not limit speed in a force 8 wind and not close traffic in a force 11 storm
Bridges with different structures, diverse shapes and unique technologies are the biggest features of Fuzhou-Xiamen high-speed Railway.
Fuzhou-xiamen high-speed railway is the fourth survey and design Institute of China Railway (hereinafter referred to as "Tiexi") responsible for the survey and design, the chief engineer of the bridge institute of Tiexi Bridge said that Fuzhou-Xiamen high-speed railway is the most diverse and complex bridge structure in China's high-speed railway, and the Bridges on the line span Meizhou Bay, Quanzhou Bay, An Bay, Wulong River, Jiulong River and other bays and big rivers. Fuzhou-xiamen high-speed railway also crosses the G324 National Highway and Shenhai, Fuquan, Xiarong, Quanzhou Ring City and other expressways, as well as Fuxia, Yingxia, Xiashen and other railways. According to statistics, 84 new Bridges have been built on the main line of the Fuzhou-Xiamen high-speed railway, with a total length of 181 kilometers, accounting for 65.3%.
Compared with ordinary Bridges, the design of cross-sea Bridges is more difficult. To this end, the design and construction side of Fuzhou-Xiamen high-speed railway has carried out special research on the construction technology of large-span simple supported beams at sea, the bare tower rotating technology of single-tower concrete cable-stayed bridge, the corrosion resistance technology of Marine atmospheric environment, BIM (building information modeling) technology, and bridge health monitoring.
Taking Quanzhou Bay cross-sea Bridge as an example, Quanzhou Bay is located in the coastal high wind speed zone, with large wind speed and complex wind conditions, and the number of days with 6 or above wind power reaches 91 days throughout the year.
In order to solve the problem of wind, to ensure that the bridge is stable in strong winds, and to maintain the continuity of high-speed train operation, they adopted a lot of new structures and new technologies.
The first is the structural design innovation of the bridge main tower modeling. Luo Changwei, chief engineer of the new Fu-Xiamen Railway six standard project of the Second Aviation Bureau of China Communications, said that the main beam adopts the flow line box structure, and additional effective pneumatic measures such as deflector, vibration reduction railing and cable eddy current damper. "These structural designs allow the bridge to bypass the wind direction and reduce wind-induced vibration in complex wind environments."
The second is to adapt to the corrosive atmospheric environment of high salt and high humidity, and solve the corrosion problem of the Marine environment on the bridge. In Quanzhou Bay cross-sea Bridge, from a distance, you will find that the lower part of the pier presents a white section. "It's a special anticorrosive material." Luo Changwei said that several cross-sea bridge cable tower steel anchor beams and supports of Fuzhou-Xiamen high-speed railway are using new materials, the first time in China to use Marine atmospheric corrosion resistant steel, as well as non-painting (no paint), no dehumidification system, becoming the world's first large-scale cross-sea project using non-painting weathering steel.
The main span is 400 meters, and the two main towers in the north and south are 160.254 meters high, which is equivalent to the height of more than 50 stories. As a long joint and high pier cross-sea bridge, Quanzhou Bay Cross-sea Bridge is located in the high-intensity earthquake area on the west bank of the Taiwan Strait, and it has to face the seismic problem. The design team solved this problem by using longitudinal viscous dampers, shear-resistant hyperbolic spherical steel bearings, a comprehensive vibration isolation system and technology of metal dampers, and a monolithic rigid frame bridge without bearings.
Through wind tunnel tests, several cross-sea Bridges of the Fuzhou-Xiamen high-speed railway have reached the goal of running at 350 kilometers per hour in a level 8 gale without speed limit, and not closing traffic in a level 11 storm without setting wind barriers and other windproof measures.
It can be proudly said that the Fuzhou-Xiamen high-speed railway has brought China's bridge construction technology to a new level. In the design process of Meizhou Bay cross-sea bridge, the design team designed the main bridge as a prestressed concrete continuous rigid frame low tower cable-stayed bridge, the main span of 180 meters, across Meizhou Bay planning 3,000 tons of channel, the north and south two double column type main tower, the tower above the bridge floor is 30 meters high, creating the country's first cross-sea high-speed rail short tower cable-stayed bridge. During the construction process, all the offshore approach Bridges of the bridge were prefabricated with 40m simple supported beams, which greatly shortened the offshore construction period. The large-scale engineering application of simple supported beams with spans from 32 meters to 40 meters in high-speed rail construction marks a major improvement and breakthrough in high-speed rail construction technology.
In more than six years of construction, the builders of the Fuzhou-Xiamen high-speed railway have adhered to the "one bridge, one policy" and successfully solved a series of problems such as sea wind and seawater corrosion, seasonal typhoon impact, and high-speed railway bridge deformation. More than 10 kinds of latest construction technologies and processes, such as sediment separator, concrete overfilling reminder instrument, ultrasonic hole inspection instrument, intelligent temperature control system, have not only opened up the key links in the construction process, but also filled a number of gaps in the field of high-speed rail construction in China, and achieved a new breakthrough in high-speed rail construction technology.
Ballastless and ballastless, do not slow down across the sea
The bridge deck may lay ballastless tracks with independent intellectual property rights, or lay high-tech ballastless tracks to ensure that high-speed trains cross the sea at 350 km/h
Driving on the cross-sea bridge is greatly affected by the sea wind. Generally speaking, in order to ensure driving safety, it is necessary to slow down through such sections, but the Fuzhou-Xiamen high-speed railway has achieved "crossing the sea bridge without slowing down".
An Bay Bridge is not only the final work of Fuzhou-Xiamen high-speed railway cross-sea bridge, but also the "opening work" of the world's ballastless track bridge "big span" and "cross-sea".
Ballast-a small stone on a railroad that surrounds the track. The reason why the large bridge of An Bay is built into a large-span cable-stayed bridge with ballastless track across the sea is mainly because the ballastless track can avoid the splashes of the ballast, its smoothness and stability are good, and vehicles need not slow down when passing. However, this kind of track has very high requirements for construction technology and settlement control.
The "large span" and "sea crossing" properties of An Bay Bridge make it extremely challenging to bridge on ballastless track. After repeated simulation tests, the design team found the structural parameters of the steel-concrete composite beam that adapt to the conditions of "long span" and "crossing the sea". The full-length steel-concrete composite beam was adopted, and effective pneumatic measures were adopted for the main beam, which met the technical requirements of high-speed trains passing across the sea bridge. The bridge deck is laid with CRTS Type I double block ballastless track with independent intellectual property rights, so that the high-speed train crossing the sea bridge at 350 km/h does not slow down. Once in service, the 350-km-per-hour train will cross the 650-meter-long main bridge in less than seven seconds and cross the entire sea in 98 seconds.
On the Quanzhou Bay cross-sea Bridge, the ballasted track can also run out of the ballastless track. The maximum operating speed of the traditional ballasted track is 250 kilometers per hour, and the Quanzhou Bay cross-Sea Bridge for the first time uses a polyurethane solidified ballast structure to "fix" the ballast, so that in a strong wind environment, high-speed rail trains can also pass the bridge at 350 kilometers per hour.
Behind the miracle of creating speed, how to ensure the safety of the bridge rail? Liang Jinbao, head of the design of Fu-Xiamen high-speed railway bridge health monitoring system, revealed that by integrating modern information technologies such as intelligent sensing, intelligent Internet of Things, edge computing, and geographic information, the "bridle-rail integration" 24-hour real-time monitoring management platform has recently begun to operate.
Liang Jinbao told reporters: "After the high-speed rail enters the operation phase, this system will quickly diagnose the structural status of the entire bridge rail, overcoming the shortcomings of artificial operation and maintenance of Marine Bridges." The powerful information gathering capability enables real-time monitoring of key indicators, and regular daily, monthly and quarterly reports are generated to help us evaluate the specific condition of the entire bridge track."
Digital "twin", tree wisdom benchmark
The railway on the drawing is three-dimensional, solving the "dead corners" that can not be seen on the original drawing, and cooperating with the intelligent construction and intelligent operation and maintenance
Fujian mountains to the sea, water network interlaced, landscape barrier, is the Fu-Xiamen high-speed rail designers can not get around the problem.
From the line patterns on the drawings to the reinforced concrete in reality, the design team of the Fourth Survey and Design Institute of China Railway needs to consider a lot.
As a cross-sea railway, the Fuzhou-Xiamen high-speed railway is close to the bay, the bridge and tunnel ratio is as high as 85%, including four high-risk tunnels, there are water and mud gushing, fault fracture zone, goaf and other bad geology, coupled with the special bridge span, complex structure, etc., the construction is very difficult. At the same time, there are more than 100 places on the Fuzhou-Xiamen high-speed railway that cross or are adjacent to existing expressways and railways, and security control is difficult.
Digital construction and intelligent construction technology play a key role in the whole life construction cycle of Fu-Xiamen high-speed railway.
The design team adopted cloud computing, Internet of Things, big data, artificial intelligence, mobile Internet, BIM, GIS, Beidou and other advanced technologies to set up a new benchmark for intelligent construction of high-speed rail.
Sun Zechang, chief designer of Fuzhou-Xiamen high-speed railway BIM, said that BIM technology has been applied professionally across the whole line in railway construction in Fujian for the first time, including 20 professional projects such as lines, Bridges, tunnels, roadbeds, geology, stations and yards, tracks, overhead contact lines, power supply and transformation, environmental protection, communications and signals.
"BIM technology is equivalent to 'twinning' the Fuzhou-Xiamen high-speed railway in the digital world, and 'standing up' the railway on the drawing to express the design intention more intuitively and better." It can not only solve the 'dead corners' that can not be seen on the original drawings from the design source, but also extend downstream to cooperate with intelligent construction and intelligent operation and maintenance." Sun Zechang said.
The design team used the independently developed 3D route selection design software to build a digital ground model covering more than 3,500 square kilometers of the entire line, a total of 489 standard construction models in 13 categories, and realized the model construction of 303 kilometers of Bridges, roadbeds, tunnels, stations, overhead contact lines, tracks, and overpasses. The concept models of 77 interchange roads and 7 stations are constructed.
The "four power" of railway, namely communication, signal, power and electrification works, are equivalent to the meridians, eyes, physical strength and nerves of people respectively, and together provide kinetic energy and guidance for high-speed trains. With them, high-speed rail can run, run fast, and run steadily. On the smart construction site system with BIM as the development platform, the "four power" intelligent equipment is no longer a "stand-alone version", but enters the networking mode. A series of achievements such as intelligent safety experience area, intelligent pre-distribution area of CATenary network, intelligent construction base, etc., realize visualization, digitization, and whole process management of the whole life cycle of railway "four power" project, reduce collision and rework, improve construction quality, and ensure construction safety.
Low carbon environmental protection, high-speed rail "green" meaning
In the process of route selection, avoid forest parks and drinking water source protection areas; The new station building is equipped with a roof lighting machine, which transmits sunlight to the underground space for lighting, greatly reducing carbon emissions
Not only does the construction of Bridges and tunnels create miracles, but the design and construction of the Fuzhou-Xiamen high-speed railway and station buildings also reflect green and low-carbon environmental protection.
There are 8 bus stations in Fuzhou South, Fuqing West, Putian, Quangang, Quanzhou East, Quanzhou South, Xiamen North and Zhangzhou. Luo Junwen, design director of the design team of the fourth Railway Institute, introduced that the Fuzhou-Xiamen high-speed railway passes through the southeast coast of Fujian, where the economy is developed, the population is dense, and the natural ecological environment is good. There are nature reserves, scenic spots, forest parks, drinking water source reserves and so on.
"During the design process, ecological protection was considered throughout the whole process." Luo Junwen told reporters that in the process of route selection, they comprehensively investigated the vegetation, phytoplankton types, amphibians, reptiles, birds, mammals, zooplankton, etc., through avoiding forest parks, drinking water reserves and other measures, to achieve the maximum ecological and environmental benefits, the Fuzhou-Xiamen high-speed rail into an ecological landscape gallery.
At the same time, the design of Fuzhou-Xiamen high-speed railway took into account how to coordinate with the surrounding culture and nature. The selection of the high and low towers of the main bridge of the Wulong River not only met the requirements of the waterway, but also echoed the peaks on both sides of the Wulong River. The main bridge of Quanzhou Bay Bridge is shaped like a shell, and the railings on the bridge are also marked with the LOGO of sea silk sails. Seen from a height, the whole bridge looks like a floating ribbon, which fits Quanzhou as the birthplace of sea silk culture. Meizhou Bay approach bridge adopts large-span simply-supported beams, which reduces the construction risk in the sea area and is simple and clear, integrating with the vast sea area.
In the design and construction of Fuzhou-Xiamen high-speed railway, the concept of green environmental protection is also reflected in many details. For example, the roof of the newly built transfer center of Xiamen North Railway Station has installed the largest weather-sensing smart skylight in the country at present, with an area of 1400 square meters, about the size of three standard basketball courts. Pan Fengtan, chief engineer of Xiamen North Station Project of China Railway Construction, said that through the wind and rain sensors distributed around, the skylight can automatically open and close the glass and curtains according to the real-time monitoring of light, rainfall, wind and other environmental data, fully improve the indoor environmental quality, and bring comfortable transfer experience for passengers. It is estimated that the smart skylight will reduce the operation of the ventilation system by 40 days per year, equivalent to a reduction of 14.13 tons of carbon dioxide emissions.
In the transfer center underground minus 10 meters, the specially constructed passenger distribution space, the environment is closed, but here, there is no natural light without lamps, passengers can get the comfort of the ground space, thanks to the new Xiamen North Station in the first comprehensive use of the intelligent optical fiber system.
How does this smart fiber optic system work? Originally, the 82 sets of daylighting machines installed on the roof automatically wake up every day like sunflowers, accurately track the orientation of the sun, and transmit the collected sunlight to the underground space through large flux special fiber optics to replace the lighting.
"The fiber optic lighting covers an area of 7,000 square meters, which is equivalent to installing a huge skylight for the underground part." According to Pan Fengtan, the primary energy utilization efficiency of the system is as high as 80%, and the annual electricity saving is about 720,000 KWH, which is equivalent to reducing the emission of 565 tons of carbon dioxide.
In the newly built Xiamen North Railway Station, the waiting hall of more than 20,000 square meters can achieve rapid cooling within 15 minutes, and thousands of lamps can be grouped to achieve scene lighting. "All mechanical and electrical equipment such as air conditioning, lighting and ventilation are managed by iBMS intelligent control system." Zhu Rongzhao, head of Fu-Xiamen high-speed railway power professional, said that the system can also replace manual inspection, automatically analyze and judge the operating status of mechanical and electrical equipment, and automatically implement dynamic adjustment under different environmental parameters, so that all equipment is always in the optimal energy consumption state.
