Internship location: Wuhan, Hubei Province
Intern: Lv Wei/01Class 203 /200 13 1550072.
First, the purpose of internship
Graduation practice is an integral part of the whole graduation design teaching plan, and it is a practical field named Xu Earrings in civil engineering specialty. Organize visits and special technical reports, collect data and materials on graduation design topics, and lay a good foundation for graduation design. The internship should aim at:
1, the whole process of industrial and civil buildings or road and bridge engineering design;
2. The general layout of the building, the classification and function of the building, the types and characteristics of the structure, the arrangement of structural members and the load transfer route, the structure and methods of the main nodes and other details. ;
3, the construction method of the building;
4. The relationship between architecture, structure and construction;
5, the latest and development direction in the field of building structure.
Second, the internship location and content
The five-day internship plan and schedule of the teaching and research section of road and bridge engineering were transferred to the site of Tianxingzhou Bridge in Wuhan and the stations along Wuhan light rail. The internship locations and locations are listed as follows:
Date, week and place
3.2 1 A short film, Bishop of Engineering Department of Wuhan University
3.22 The second on-site inspection on the construction site of Tianxingzhou Bridge
3.23 Three technical reports of Tianxingzhou Bridge Construction Office
3.24 Four field trips along Wuhan Light Rail.
3.25 Lecture by Bishop of Five Engineering Departments
First, short film observation
In the morning, I mainly watched the example videos of road and bridge projects across the sea, river and river, and briefly reviewed the construction technology and process. First, the planning and design from Kaohsiung, Taiwan Province Province to Danshui expressway. The scheme demonstration of this project introduces the location of each mid-point city, the terrain along the way and the connection of each branch road, and considers the construction and connection of expressway network along the island, which is also very important in environmental protection-specially hired animal and plant experts to evaluate and test the environment during and after the construction of this project, and consider it in the design and planning. This is done at home. After that, I contacted the records of road construction and arch bridge construction in many countries, such as the United States, and introduced the new technology and new technology of road and bridge.
In the afternoon, watching slides, the construction process of Yangluo highway Yangtze River Bridge was simulated and displayed with realistic three-dimensional animation, and studied; Since then, the initial demonstration of the Shinkansen project in Tohoku, Japan, and the construction of a large highway bridge in Thailand, despite the language barrier, still have multiple purposes of cognition, learning and thinking because of the detailed system and repeated playback of the pictures.
The following briefly introduces the construction work of the above three projects in turn:
1, Yangluo bridge system is a suspension bridge. Jiangsu Runyang Yangtze River Bridge under construction has a span of 1.490 meters, which is a world-wide suspension bridge. The characteristic of suspension bridge is that it can span the unparalleled super-long span of the bridge type, and because the force is simple and clear, the rolled steel basket is easy to transport, and the cable can have a solid and stable structural support system after erection, and the risk in the construction process is small. The slipway construction process of Yangluo Bridge is as follows:
(1) working face surface;
(2) the construction of the excavation groove section;
(3) North anchorage construction;
(4) Cable tower construction;
5] template pouring concrete tower;
[6] Installation of cable system of main bridge and installation of bridge segments.
Because the soil quality of the north and south banks of Yangluo Bridge is different and the construction scheme is different, one side of the soil can be directly excavated. On the other hand, it belongs to sandy muddy soil, so concrete should be excavated, and concrete should be filled down at the excavated outer diameter of ingot laying to make retaining wall. Attention should be paid to process [2] and process [5], in which the former is excavated and poured from top to bottom to prevent collapse; In the later stage of mass concrete construction, the temperature strain caused by excessive hydration heat should be controlled.
2. Tohoku Shinkansen Project in Japan
This paper introduces the construction method of moving formwork used in the Shinkansen project in Tohoku, Japan. The method is to pour the bridge hole by hole by using mobile scaffolding and assembled formwork. It consists of bearing beam, guide beam, trolley, pier support and formwork. Load-bearing beams and supporting templates are set on both sides of the box girder to bear the construction gravity. The length of the guide beam is longer than the span of the bridge, and the bearing beam is supported on the pier when pouring concrete. The guide beam is mainly used to transport load-bearing beams and movable formwork, which needs more than twice the span of the bridge. When the hole beam is constructed, it will be demoulded and unloaded, and the load-bearing beam and movable formwork will be transported to the next bridge hole by the guide beam and the front and back trucks on the existing bridge. After the bearing beam is in place, move the guide beam forward.
3. Construction of large highway viaducts in Thailand
The slide shows and introduces the length of the construction site in detail. The pier and abutment of the bridge are cast in situ, and the beam section of the bridge body is prefabricated in the factory. Its advantages are that the upper and lower structures of the bridge can be constructed in parallel, which greatly shortens the construction period, and there is no need to make high-altitude components, so the quality is easy to control, and it can be mass-produced in one place, which reduces the engineering cost. However, the disadvantage is that large hoisting and transportation equipment is needed to splice the longitudinal joints between components. Obviously, the overall working performance of splicing components is not as good as that of cast-in-place method.
B.tianxingzhou bridge
1, project overview
Wuhan Tianxingzhou Yangtze River Bridge is located in the first line from Qingshan District to Chenjiaji in Hankou, about 9.5 kilometers away from the upstream Wuhan Yangtze River Bridge. It is a tenth five-year plan construction project, which was jointly built by Hubei Province and the Ministry of Railways. The bridge was officially started on September 28th, 2004, and the contract delivery date was August 3rd, 20081day.
The total length of Tianxingzhou Yangtze River Bridge is 4657. 1m, and the span from Qingshan bank to Hangang section is 15 with 40.7m box girder+(98+196+504+196+98) m steel truss girder cable-stayed bridge +62 with 40.7m span. The total length of the public railway is 2842. 1m, which was undertaken by China Railway Bridge Bureau Group Co., Ltd. ..
2. Main bridge structure
The main bridge of Wuhan Tianxingzhou Yangtze River Bridge is a (98+196+504+196+98)-meter steel truss girder cable-stayed bridge with twin towers and three cable planes, with a length of 1092 meters. The upper highway has 6 lanes and the bridge deck is 27 meters wide; The lower-level railway is designed according to four lines, with two lines for the primary trunk line and two lines for the passenger dedicated line. The main girder is a plate truss steel truss beam, an N-shaped truss and three main trusses, with a truss width of 2× 15m, a truss height of 15.2m and an internode length of 14m. The main tower adopts concrete structure, inverted Y-shape, and the cap188.5m. There are 3× 16 galvanized parallel steel wire stay cables on both sides of the main tower. The maximum section of the cable is 45 1φ 7mm, and the maximum cable tension is about 1250 tons. The foundation of the main tower is about φ 3.4m bored pile, with 32 piers No.2 and 40 piers No.3, and the pile caps are constructed with double-walled steel cofferdam. The bridge integrates new technologies, new structures, new processes and new equipment, and is a new landmark project in China.
3, engineering innovation and characteristics
⑴ Long span of main bridge: The main span of cable-stayed bridge is 504m, which is the first span of * * * bridge in the world.
⑵ Heavy bridge load: This bridge is a highway-railway cable-stayed bridge built according to the world's four-line railway, which can bear 20,000 tons of load and is the largest highway-railway bridge in the world.
⑶ High design speed: This bridge is a long-span cable-stayed bridge for China's railway passenger dedicated line. The design speed of passenger dedicated line is 200 km/h, and the dynamic simulation design is based on 250 km/h. ..
(4) New structural type: The bridge adopts a new structure with three main trusses and three cable planes for the first time; The highway deck adopts orthotropic slab or concrete and steel truss system, and the railway deck adopts concrete and steel truss system; The main tower is equipped with a large-tonnage hydraulic damping device to limit the longitudinal displacement of the beam.
5. New construction technology: For the first time, the pier foundation of the No.2 main tower adopts a new technology of accurately positioning the anchor pier with the integral floating prestress of the giant double-wall steel box cofferdam; The pier foundation of No.3 main tower adopts the floating positioning heavy anchor construction technology of giant double-wall steel hanging box cofferdam; For the first time, a power head drilling rig with torque of 30tm was developed for the construction of φ 3.4m large diameter bored pile.
[6] Construction difficulty: The overall manufacturing, horizontal launching, floating transportation and positioning construction of the giant double-walled steel cofferdam factory with a plane size of 70m× 44m are the first in China, with high technical requirements. The plane positioning accuracy of cofferdam is within 5cm, and the verticality of steel casing is within 1/500; Construction of φ 3.4m large-diameter bored pile in conglomerate with uneven soft and hard cementation: 16000 mass concrete construction and control of square platform: the fabrication and installation of new three main trusses and new plate trusses have high construction precision, strict technical requirements and great construction difficulties; 45 1 φ 7mm long 27 1m galvanized parallel steel wire stay cable fabrication and installation; Vertical construction control of main tower with a height of 188.5m and spatial positioning of cable ropeway pipe: integral cast-in-place construction of large-tonnage box girder with its own weight of 2× 1300 tons.
4. The key technical test items of the main bridge of Tianxingzhou Yangtze River Bridge are reduced from 65,438+07 to the following 65,438+00, namely:
⑴ Dynamic characteristics analysis and live load loading standard of four-line railway;
(2) Seismic analysis and large-tonnage hydraulic shock absorber;
⑶ Wind resistance and simulation experiment;
(4) Railway concrete steel truss bridge deck system test;
5. Spatial structure and stability analysis of cable-stayed bridge with three main trusses;
[6] Structural fatigue performance experiment;
(7) Large-scale model test of typical joints;
(8) Development of temperature expansion regulator for large displacement track and expansion device for beam end track;
(9) Development of large-tonnage and large-displacement bearings;
⑽ Test new construction and manufacturing technologies.
This paper mainly studies the construction of No.3 main pier. As mentioned above, the foundation of No.3 main tower pier adopts the construction technology of floating and transporting heavy anchors with giant double-walled steel box cofferdam, and 40 φ 3.4m bored piles are used, with the pile length of 80.4m and the hole-forming depth of10/m-102m, which reaches the underground rock foundation and belongs to the end bearing. Because the hole-forming depth and aperture rank first in China, China Railway Bridge Bureau organized technical public relations, and developed a power head drilling rig with a torque of 30tm for the first time, which was used for the construction of φ 3.4m large-diameter bored piles.
On the day of the internship, Mr. Zhang gave a technical report with high gold content. Finally, he sent a meaningful sentence: bridge skills, never. It is a spur and encouragement, and it should be the unremitting ideal and pursuit of every bridge designer and builder.
C. Wuhan rail transit
Station, visited the first phase of Wuhan light rail project with a total investment of 265,438+99 million. The total length of the project is 10.234 km, and there are Zongguan and Pacific stations 10 along the way. It was completed and put into use in July 2004. It was originally equipped with the 12 train. Each train has 4 carriages and can carry 950- 1200 passengers. The average speed of design and operation is 34.5 kilometers per hour, and the top speed can reach 80 kilometers per hour. The distance between the two stations is short, and the actual top speed is only 50 kilometers per hour, but its average speed is still higher than that of ordinary road traffic vehicles. It only takes 17 minutes from Huangpu Road to Zongguan Waterworks.
The first phase of light rail 1 Line adopts integral viaduct, and the pier adopts box-type simply supported beam structure. Its construction technology adopts ballastless track construction, and the process flow is as follows: bridge deck-datum point measurement-turnout rail material on the bridge-paving turnout rail-turnout support block on the bridge-connecting turnout rail-erecting turnout and aligning fittings-supporting block on the bridge-coarse adjustment of turnout rail state-steel bar binding and welding-fine adjustment of turnout-rail state inspection-pouring pier-dismantling support frame-rail state inspection-assembling rail bearing platform template-pouring.
At the intersection of the project and Beijing-Guangzhou line, the viaduct becomes larger. Considering the control of trains in the future, the traffic standard of double-decker trucks is adopted. Technicians repeatedly explained the construction situation at the intersection: they had specially reported to the railway for approval, and the Beijing-Guangzhou line was interrupted for two hours at night to get valuable construction. The light rail is divided into two lanes after crossing, and its platform is located in the middle, which is called "island station". At Zongguan Station, the vehicle lane is set up in the project, and the rail is made for the traction power of the double-headed car.
How to organize construction emergency repair and how to properly handle official business is something that every technician should study hard after on-site construction.
D. Special lectures
I was lucky enough to invite Dean Xu from the Survey and Design Institute to give a special lecture. Director Xu made the following discussion on the qualities that professional engineers and technicians should possess:
There must be an inauguration ceremony, the principle: jump, reach;
B, from now on, cultivate quality (thought-habit-character-destiny);
C, cultivate thinking methods, clear thinking;
D, be good at grasping opportunities;
E, appropriate interpersonal relationships;
F, in a division of labor society, we should do our own work well;
G, treat "name" and "profit";
H, cultivate the ability of learning, writing, discussing and reading;
I. Ability to face peace;
J, cultural taste;
K, love civil engineering and career.
Subsequently, (this article belongs to the voice of secretaries, please visit www.wm338.com for more articles) had a heated exchange on professional theoretical knowledge about employment and career choice. Many of his suggestions and experiences are valuable for reference, and they have benefited a lot.
Third, the internship summary
Although this internship is short-lived, it has achieved the multiple purposes of collecting data for graduation design and integrating theory with practice.
In the practical project, the whole process of road and bridge engineering design is introduced, and the new trend, new method and new construction technology of structural design are introduced.
The essence of internship is the simulation exercise before graduation, and it is the key to sharpen when you are about to step into the society and set foot on your job. I hope life can be extended from this, and I can really apply what I have learned.