With the rapid development of social economy and traffic in China, the construction of bridges is increasing gradually, and the technical requirements for construction and maintenance are getting higher and higher. Based on many years' working experience, this paper puts forward some views on bridge engineering construction technology for reference.
Keywords: bridge engineering construction technology
With the gradual acceleration of urbanization and the rapid development of bridge construction in China, the quality of bridge construction is very important.
In order to prevent the occurrence of construction quality and safety accidents, the author, based on years of experience, talks about some superficial understanding of the technical points of bridge engineering construction and reinforcement.
I. Key points of bridge engineering construction
Before the bridge construction preparation, attention should be paid to the detection of various construction tools to prevent the occurrence of machine failures. In addition, enough parts should be reserved for wearing parts and tools. For example, when using a drilling rig, you should pay attention to many key points, because the drilling rig will work continuously under overload, so the drilling rig is easy to be damaged, and enough parts should be stored.
In addition, it should be noted that in the process of bridge concrete pouring, all the influencing factors should be understood in time to ensure the smooth and safe pouring work. Secondly, in the process of bridge construction, there should be enough accurate plans to ensure the orderly construction.
Therefore, in the process of concrete pouring, there can be no time interval, so the solidification time of cement is very fast, and a little time interval will have many adverse effects on the quality of the bridge.
When pouring near the last slab, the discharged mud may be too thick and should be removed and dredged.
In order to better implement the bridge engineering construction technology, the following measures can be taken. For example, in the minds of many bridge engineering construction technicians, few people can realize the important role of bridge engineering construction technology update. Because many front-line workers and grass-roots managers lack the corresponding theoretical knowledge of bridge engineering construction technology and do not understand the process and objectives involved in bridge engineering construction technology update, it is necessary to increase the training of bridge engineering construction technicians.
At the same time, we should also pay attention to the normal information communication between the bridge engineering construction technology project teams.
This will get better results.
Second, the bridge engineering construction preparation
According to the overall construction layout and structural form of bridge engineering design, including topography, landforms, external environment, hydropower facilities, access roads, etc. Before the project starts, it is necessary to further investigate and verify the construction site, work out detailed construction technical scheme, project quality assurance plan and material supply plan in combination with the actual technical ability of the construction unit, further clarify the construction progress plan, construction control points, key process control and quality inspection evaluation standards, and carefully organize the implementation after being approved by the supervision engineer.
The preparatory contents of the preliminary work mainly include the construction access road, temporary water supply and power supply, the construction of temporary houses for production and life, the hardening treatment of the data storage site, the inspection and test of various raw materials, and the devices and methods of the equipment entering the site, so as to make all preparations for the formal commencement.
Third, strictly implement the bridge construction technology
1, check before pouring.
It mainly includes: the inspection of supports and templates, the inspection of the position of steel bars and steel members, and the preparation work before pouring concrete.
2. Concrete pouring.
It mainly includes: determining the pouring speed of concrete and determining the pouring sequence of concrete; Preparation before pouring concrete.
3. Precast installation.
Crane erection method, bridge erection method, bracket dyeing method, simple machine combination method, iron tower erection method, etc.
4, bridge construction process control.
Control the bridge construction process, ensure that the internal force and deformation of the bridge structure in the construction process are always within the allowable safety range, and ensure that the completed bridge state meets the design requirements.
Fourth, the bridge reinforcement technology
The strengthening technology of superstructure of beam bridge mainly includes enlarging cross section, external bonding, external prestressing, changing structural system and adding longitudinal beams.
The method of increasing cross-section reinforcement is to increase the cross-section area of members. According to the different load and clearance conditions, it can be divided into two reinforcement schemes: increasing cross-sectional area and increasing steel bars.
External bonding method is a method of bonding steel, glass fiber reinforced plastic and other materials used to strengthen the legal system to the outside of the structure with adhesives such as epoxy resin to improve the bearing capacity of the structure.
It is suitable for the occasions where the component size is limited, but the bearing capacity of the structure must be greatly improved and the quality of the adhesive must be guaranteed. External prestress reinforcement method refers to a kind of reinforcement method that applies prestress principle to impose certain initial stress on new members or original members.
By applying prestress to the tension zone, part of the dead weight stress can be offset, which can play the role of unloading, reducing mid-span deflection, reducing crack width or closing cracks
Changing the reinforcement method of structural system is a reinforcement method by adding supports or piers, changing simple support into continuity, and adding stiffening beams such as steel frames or composite beams under the beams to reduce the peak bending moment of the control section in the beams and improve the bearing capacity.
When the pier foundation of the bridge is stable and has enough bearing capacity, new longitudinal beams with high bearing capacity and high stiffness can be added, and these new longitudinal beams are connected with the old longitudinal beams and bear the same force.
Due to the redistribution of vehicle load in the bridge structure with new main girder, the load in the original girder is reduced and the bearing capacity and stiffness of the strengthened bridge are improved.
When the added longitudinal beam is located on one side or both sides of the main beam, it has the function of widening.
This method is suitable for the case that the foundation of beam structure is intact and the bearing capacity can not meet the requirements.
Verb (abbreviation of verb) Construction of bridge deck system
After the plate girder erection is completed, the bridge deck system construction can be carried out, such as joint filling, bridge deck pavement, sidewalk slab and railing installation, etc. Before the bridge deck pavement, the transverse connection reinforcement between beams has been laid and the joint concrete has been poured as required. When paving the bridge deck, we should pay attention to the position of steel wire mesh. Angle steel is used for side formwork. After adjusting the elevation, tighten the screws and caulk the joints with mortar under the angle steel.
Concrete shall be tamped with plug-in tamper and vibrating beam.
After pouring, concrete curing should be strengthened. After the concrete reaches a certain strength, it will be embossed with an embossing machine, and the embossing depth is 1-2mm.
Expansion joints shall be installed with reserved slots, which shall be smooth, firm and durable.
Sidewalk slabs and railings are prefabricated in the prefabrication yard and then transported to the site for installation.
Only after the pavement slab is paved can the railings be installed. During installation, align and level the whole bridge, and fix it with cement mortar after it is vertical.
Six, long-span bridge construction technology
In recent years, with the continuous enhancement of China's comprehensive national strength, world-class super-long span bridges with various structural forms, such as Sutong Yangtze River Bridge, Qiaotianmen Bridge and Taizhou Bridge, have been built or started construction, which has also made great progress in China's bridge construction technology.
Because it is a super-long span bridge, its construction technical requirements are stricter than those of large, medium and small bridges. For example, the platform design and construction of Sutong Yangtze River Bridge adopts steel liners as the supporting structure of the platform and super-large diameter bored piles; Taizhou Bridge requires high positioning accuracy of open caisson, but the settlement deviation is difficult to control. The rigid guiding positioning system is an example of the combination of bridge construction technology and information technology. Sutong Yangtze River Bridge adopts climbing formwork system for concrete construction of the tower body to ensure the linear shape of the tower body.
About the author: Wang Wengang (198565438+February-), assistant builder, works in China Railway 18th Bureau Group Co., Ltd.
References:
Zhai fanlei. On the Construction Technology of Bridge Engineering [J]. Guide to Getting Rich by Science and Technology, 20 1 1(20).
[2] Zhai Ao. Overview of Bridge Engineering Construction Technology [J]. Guide to Getting Rich through Science and Technology, 20 12(3).
Technical management of bridge engineering construction II.
Abstract: The key part of all kinds of projects is project quality, which is also the goal of the whole project.
Its quality is related to people's life, production and safety of life and property, as well as national construction and social stability.
Therefore, in the process of engineering construction, the control of engineering quality is the most important.
This paper mainly analyzes the problems that affect the quality and safety of bridge construction management, and puts forward the measures to solve the problems.
Keywords: bridge engineering; Management; Quality; safety protection
Bridge engineering is an important link in highway construction. Only by ensuring the quality and safety of bridge engineering can we maintain the smooth progress of transportation and the normal operation of the national economy.
Only by strictly controlling the quality of bridge engineering can we ensure the normal operation of the whole highway construction. Highway is the lifeblood of national economic construction and development. In order to do a good job in the economic hub project, better serve the sustainable development of the economy and better protect the security interests of the people.
Quality control of bridge construction must be strengthened.
Only by being familiar with the potential influencing factors of construction details and combining with the relevant provisions of the code can we formulate a feasible scientific system and reduce the influence of various factors on bridge construction quality.
1. Various influencing factors of quality control and safety control in bridge construction management
1. 1 human factors
Human factors involve a wide range, mainly including leaders and construction technicians.
In recent years, many bridge construction quality problems and other accidents in China are caused by the low quality and irregularity of Party A's personnel.
The legal person and owner of the project will also affect the quality of the project.
In addition, the quality of personnel directly involved in bridge construction is also an important influencing factor.
1.2 external factors
The external factors mainly include: (1) Building materials are the dominant factor in the external construction of the bridge and the key factor to ensure the quality of the bridge project.
Whether the selected building materials are qualified is directly related to whether the bridge construction meets the standards and whether the quality can meet the standards.
(2) Mechanical equipment is an indispensable tool in today's bridge construction.
Modern bridge construction method can not be separated from modern equipment, so the condition of equipment also directly affects the quality and progress of bridge construction.
In addition, the rational use and maintenance of equipment is the key factor to ensure the normal development of the project as scheduled.
(3) Construction technology and methods are also important factors affecting the quality of bridges.
Whether the construction method is correct or not and whether the construction technology is scientific or not is directly related to whether the engineering quality can be guaranteed.
Correct construction methods and scientific construction technology are the premise and foundation to ensure the construction period and construction quality.
The lack of standardization in bridge construction will inevitably lead to the decline of construction quality.
2. Main measures to control the quality and safety of bridge construction management.
2. 1 Establish a perfect engineering quality evaluation system and responsibility system.
In the process of construction, there must be quality management system, evaluation system and supervision mechanism of bridge engineering, as well as safety responsibility system, so as to make the rights and responsibilities clear.
The construction site should have a quality supervision organization composed of leaders at all levels and relevant personnel, responsible for supervising the construction quality of various departments.
Implement the scope of responsibility for quality and safety, and supervise and inspect the bridge construction within its management scope.
All departments must strictly implement the system and regulations of project supervision and operate in strict accordance with relevant requirements.
Establish a perfect system of self-inspection and mutual inspection to effectively improve the quality of bridge construction.
2.2 Take quality assurance measures
(1) The three basic principles of construction according to design drawings, operation according to operating procedures and acceptance according to quality standards must be strictly implemented during construction.
(2) Do a good job in the handover of engineering technology, and explain the construction method, specific quality requirements, construction precautions and quality assurance in detail during the handover.
(3) Strengthen self-inspection and mutual inspection.
After each construction process is completed, self-inspection shall be conducted first, then mutual inspection shall be conducted, and sampling inspection shall be conducted when necessary.
(4) Do a good job of connecting each working procedure. After the completion of a process, it must be inspected and can only enter the next process after it is completely qualified.
Records must be made when each process is connected, and the relevant person in charge should sign for confirmation.
(5) In the event of a quality accident, it is necessary to insist on not finding out the cause of the accident, not educating the responsible person, not missing mistakes, and not doing a good job in improvement measures.
(6) The use of raw materials should be rigorous, and raw materials must have factory certificates and certificates to prevent the use of unqualified raw materials.
(7) The original construction data should be properly kept, and the compilation of the data should end at the same time as the project completion, and the data must be complete and accurate in the process.
(8) Equipped with a laboratory that can identify the quality of materials used in the project to ensure that the materials used meet the design requirements and specifications.
2.3 the implementation of total quality management
Carry out total quality management system in bridge engineering construction, improve staff awareness by strengthening staff training, and ensure the realization of bridge construction goals ideologically and organizationally.
1) Establish a post responsibility system for all employees, clarify the quality responsibility of each employee, make the responsibility to people, implement the principle of rewards and punishments, reward the excellent and punish the poor, and mobilize the enthusiasm of each employee.
2) Organize relevant personnel to strengthen their study, abide by the operating procedures, and organize construction in strict accordance with the design operating procedures and the specific requirements of the supervision engineer.
Before each bridge construction project starts, there should be detailed construction scheme, method and technical disclosure.
3) Strengthen professional technical training and improve professional operation skills.
Key technical jobs must raise requirements, strengthen supervision, and select experienced, high-level and capable personnel to take the lead in organizing and be fully responsible for quality control.
4) The whole process of construction must be supervised, and the supervision engineer should give full play to the role of supervision, inspection and guidance.
2.4 Strengthen the safety construction work
In the bridge site construction, a leading department with the project manager as the leading center should be established, the person in charge of safety should be appointed, and various specific measures should be formulated to ensure safety technology.
These are the preconditions to ensure that the construction is completely under safety control.
All employees must also fundamentally establish the idea of safety first.
2.4. 1 Strengthen safety construction.
In bridge construction activities, it must be carried out in strict accordance with safety work standards.
1) Review the safety qualification of the employer and ask the construction team leader to show the safety production certificate.
2) Sign a safety contract with the employer.
3) Do a good job in front-line safety management of construction.
4) Do a good job in training and safety education for construction personnel before taking up their posts.
5) Establish and improve various safety rules and regulations and implement various safety responsibility systems.
6) Do a good job in safety technical disclosure and process handover, and all operators must strictly implement the safety operation procedures of this type of work.
7) Personnel entering the construction site must dress and wear safety helmets as required, and aerial work personnel must use corresponding safety devices.
2.4.2 Strictly implement and learn relevant safety construction specifications.
Bridge construction site should strictly implement the construction safety norms and construction safety norms.
Construction personnel should always keep in mind the importance of observing safety regulations during construction.
Check the safety standards for construction, the specifications for temporary electricity consumption on the construction site, the technical regulations for the safety of working at heights on the construction site and other rules and regulations related to the safety of the construction site, which should be posted in an eye-catching position, so as to attract enough attention of the construction personnel.
In addition, it is necessary to educate all relevant personnel with the concept of prevention first and strengthen their ideological understanding.
It is necessary to establish the idea of attaching importance to safety and realize the important significance of safe construction and production. The idea of putting prevention first and safe construction should run through the whole process of safety education and training.
We should pay special attention to safe construction in line with the idea of preventing minor delays and nip in the bud.
2.4.3 Attach importance to safety construction ideologically.
Safety construction is an important factor to ensure the quality of bridge construction and the use effect. Safety covers a wide range of contents, including all kinds of safety in the construction process and future use safety of bridges.
Safe construction and use can save resources and time and avoid unnecessary waste caused by frequent maintenance of bridges.
3. Conclusion
In short, in the construction of bridge engineering, the construction must be carried out in strict accordance with the required standards, to ensure that every link and every working procedure is the best, managers should constantly improve their own quality, builders need to constantly improve their professional skills, and inspectors should conduct testing in strict accordance with relevant standards, so as to finally ensure the quality of bridge engineering.
refer to
[1] Liang Zhuohua. Analysis and measures of highway bridge construction quality control [J]. Urban construction. 10 ( 10) .20068.000000000006
[2] Yang Zhihui. Talking about the quality control measures for creating excellent projects [J]. Fujian Building Science and Technology, 2007(3).
[3] Sun. Discussion on quality management of building engineering construction. Shanxi Architecture, 20 10(8).
Wang Yudong. Safety management of expressway bridge construction in mountainous areas [J]. Communication Science and Technology Heilongjiang, 2011(4):17-18.
Zhao Jian. Analysis of bridge construction quality control and solutions to common problems [J]. Quality and safety, 2009 (5): 30-3 1.