How to determine the first, second and third types of pile foundations of bridges?

How to determine the first, second and third types of pile foundations of bridges? Pile foundations are divided into four categories. See Article 3.5. 1 2003/JJJ12003:

Class I: Pile body is intact.

Class II: There are slight defects in the pile, which will not affect the normal bearing capacity of the pile structure.

Class III: There are obvious defects in the pile, which affect the bearing capacity of the pile structure.

Class Ⅳ: The pile body has serious defects.

Integrity is the change of pile size, material compactness and continuity.

The defects of piles refer to fracture, crack, mud inclusion, cavity, honeycomb, looseness, etc.

Class Ⅳ piles should be treated by engineering.

Excuse me, how is the pile foundation spacing of continuous beam bridge determined? Pile spacing is determined according to JTG D63-2007 specification.

The sixth chapter is about the structural requirements of pile foundation, specifically, the distance between friction piles is not less than 2.5 times the pile diameter, and the diameter of rock-socketed piles (column piles) is not less than 2.0 times the pile diameter.

How to distinguish between bridge pile foundation and pier? Generally speaking, a pier is a pier on a foundation, and a pile is the foundation of a pier or a bridge column. The two are mainly distinguished according to the structure and function. Pier is a column or wall-like force transmission component, and pile is the lower foundation component. When the two are combined, the combination part is the boundary, which is above the pile cap or at the bottom of the pier.

If there is a cap or tie beam, there is a pile foundation under the cap or tie beam and a pier on the cap or tie beam;

No cap or tie beam: pile foundation below ground level, pier column above ground level. The pier consists of three parts, the lower part is the pile foundation, the upper part of the pile foundation is the cap, and the upper part of the cap is the pier body. The dividing line between pier and pile foundation is pile cap.

How to set out the pile position of bridge pile foundation After the pile foundation diagram is converted into absolute coordinates in cad, any pile position on the query diagram is the coordinate to be set out. Setting out can be done by GPS or total station.

Bridge pile foundation, what is bridge pile foundation? Pile-a cylindrical member buried in soil, whose function is to transfer the load of superstructure to deep hard soil layer or low compressibility rock layer;

Pile foundation-The foundation pile and the cap connected to the top of the pile are made of the same material. If the pile body is completely buried in the soil and the bottom of the pile cap is in contact with the soil, it is called low pile cap pile foundation; If the upper part of the pile body is exposed to the ground and the bottom of the cap is exposed to the ground, it is called high cap pile foundation.

Bridge foundation-the part of the bridge substructure that contacts the foundation is called the foundation; The lowest structure of a bridge. It is directly located on rock or soil foundation, and its top is connected with pier or abutment, which is collectively called bridge substructure.

The function of bridge foundation is to bear all the loads of superstructure and transfer them and the loads of substructure to the foundation. Therefore, for the safety and normal use of the whole bridge, the foundation and foundation are required to have sufficient strength, stiffness and overall stability so that it will not produce excessive horizontal displacement or uneven settlement.

What is the bridge pile foundation? A deep foundation consisting of piles and caps connecting the top of piles is called pile foundation for short.

Pile foundation has the characteristics of high bearing capacity, small and uniform settlement, which can be applied to almost all kinds of engineering geological conditions and various types of projects, especially for heavy buildings (structures) built on soft foundation. Therefore, pile foundation is widely used in coastal and soft soil areas.

The number and arrangement of piles in pile foundation should be determined according to the superstructure and load. The pile foundation under the column can adopt a pile or a group of piles, which are arranged in a polygon; Pile foundations under walls are often arranged in rows. When the load of buildings is large and the floor area is small, they should be arranged in pieces into full piles. When the load acting on the pile foundation is mainly vertical load, the pile is vertical; If there is a large horizontal load, it is necessary to arrange inclined piles to resist the horizontal force.

Due to the variety of pile foundations, great differences in construction technology and complex stratum changes, the pile body may have defects such as shrinkage, enlargement, mud inclusion, segregation and broken pile during construction. Of course, mechanical excavation and collision after construction will also cause shallow pile defects. The existence of pile defects will change the normal working characteristics of foundation piles, thus causing potential danger to the foundation. In order to ensure the safety of foundation, it is inevitable to evaluate the integrity of pile body through acceptance. A large number of practices have proved that the low-strain dynamic testing technology of foundation piles is a very effective means to judge the integrity of pile bodies (convenient, fast, economical and with a large number of tests).

Three months' practice of bridge pile foundation has ended. During these four months, I witnessed the construction of a bridge. During this time, I have learned a lot and learned the difference between theory and practice. Similarly, this is the first time that I came into contact with real architecture when I entered this major. Looking at it standing in front of my eyes, I have unspeakable excitement, unspeakable pride and endless regrets.

You can only learn superficial knowledge in school, but you can only learn more knowledge in practice. Only learning can make progress, and only progress can find gains. This internship, I came to Chengchi Project Department for internship, and laid my own basic skills in the internship, which made me full of expectations for my future work. Although my basic skills are not very comprehensive and there are still defects, I am more confident in my work. Of course, the past has become history, and we still need to work hard in the face of the future.

After reporting to the project department, he was assigned to work in a work area of Chengchi project department. Here, my work is arranged to survey, and then I apply to transfer to the bottom of the dam, because I can learn more in different locations. However, it has always been my dream to be a field technician. I am very grateful to the company for giving me this brand-new stage to show my ability, expand my knowledge and absorb more knowledge.

In terms of work, at the beginning, the project department assigned me the position of surveyor, and the construction of dam bottom bridge and Tianyigou bridge required very strict survey work. Later, it was transferred to the bottom of the dam for more than two months, and the main work was deck paving and beam and slab installation. The work of technicians in the construction site of bridge deck pavement and beam-slab installation is mainly divided into calculation data, inspection and data. Since the recognition is different, but those are only superficial and not worth mentioning, so I obey the arrangement of the leader and do my job full-time. Only the work assigned in place is the fastest promotion. Finally, my job was arranged as a field technician. In my usual work, I have a deeper understanding and more feelings, which also gives me further enthusiasm and allows me to learn more. Work should not be a simple job, but a better study.

Although I have had contact with the construction site myself, I often recall the scenes in my memory when I am at the construction site, but there are always some differences. We can't combine some construction procedures and specifications well, so we always feel some differences when we find problems. So I communicate with experienced masters and colleagues on the spot and through the video tutorials I have searched for many times on the Internet, and they all explain and learn seriously. So obviously, when we started our work, we had some deficiencies in our knowledge, which resulted from our thoughtlessness. At this point, in the half-year internship, after half a year's open-minded consultation and careful explanation, the problems existing in my study have been solved, which allows me to make better use of my own advantages to make up for my own disadvantages, check and fill gaps, improve my cognitive problems, and further realize that I am just a rookie with limited work experience, and I can't deeply sort out the different specifications that need to be applied in different construction sites. We can't combine the theoretical knowledge and practice well. Although the outside world is wonderful, you are wonderful if you don't have the strength to become someone else, not if you are wonderful. "Practice is the only criterion for testing truth" Practice is a mirror, which can reflect the results of my study; The construction enterprise carrying out the construction is a mirror, which can reflect the strength of the enterprise; The construction level of local buildings is a mirror, which can reflect the development status of construction industry in China. The development of China's construction industry is a mirror, which can reflect China's position in the world construction industry! I am happy for the successful completion of the internship, and I am proud and proud to contribute to the development of China's construction industry in the future!

Second, explain the job responsibilities.

The post I am engaged in this social practice can be said to be a technician. Technicians should first have a strong ability to read drawings and calculate, and secondly, the ability to lead and direct workers to construct correctly and safely. Moreover, technicians must also have the ability to deal with unexpected problems flexibly and correct drawing errors. Technicians can be said to be the soul of the whole project, and every step of construction is inseparable from technicians.

I think the basic process of this building can be divided into five stages: the first stage of drilling, the second stage of pouring concrete, the third stage of ground beam, the fourth stage of column, the fifth stage of capping beam, the sixth stage of beam erection, the seventh stage of tension grouting, the eighth stage of wet joint and the ninth stage of bridge deck pavement. There are also guardrails, baffles, scaffolding and other facilities. Technicians should pay off, stay and copy lines, guide workers to construct correctly, and work with foreman to make welders, steel workers, carpenters, electricians and scaffolders construct correctly and orderly.

As a technician, I deeply appreciate his efforts and sense of responsibility. The position of technician can exercise people very much.

Third, sharing.

The formation of each bridge is an accumulation process. Some people compare the process of building a bridge to the process of human growth, which is a very vivid example. Only when the bridge foundation is solid can Tian Tong Avenue be propped up, and only when the people foundation is solid can people stand tall. Let's share the growth process of this super-large bridge.

Step 1: Drilling holes

Technological process; Measuring and setting out → drilling preparation → drilling and excavation → earth-moving vehicles.

Key points of construction:

1, before drilling construction, the engineering quantity of drilling must be calculated, that is, the engineering quantity of drilling. According to the project scale, construction period, soil forming efficiency and existing mechanical equipment conditions, the rotary drilling rig is selected and the construction scheme is drawn up.

2, after the completion of earthwork calculation, can begin to allocate earthwork. Earthwork allocation is a comprehensive and coordinated treatment of the utilization relationship among excavation, drainage and filling. A good earthwork allocation scheme should minimize the earthwork transportation volume or cost, which is convenient for construction.

3. In order to prevent landslides and ensure construction safety, when the hole depth exceeds a certain limit, the soil wall should be protected by liners or mud.

4. Earthwork construction machinery commonly used include bulldozers, shovels, single bucket excavators, loaders, etc. Correct selection of construction machinery to speed up the construction progress.

Step 2: Pile foundation

Technological process: C30 concrete cushion →C25 ground beam

Key points of construction:

1. The building adopts reinforced concrete structure with cylindrical foundation.

Cylindrical foundation includes reinforced concrete independent foundation and ground beam under the column. This kind of foundation has good bending and shearing efficiency, and can be used under the conditions of large vertical load, low foundation bearing capacity and small horizontal force and bending moment.

Step 3: the dock.

Technological process: binding of constructional column reinforcement → measuring and setting out → erecting formwork → pouring concrete → watering and curing.

The third step is to tie the beam, the fourth step is to cover the beam, the fifth step is to frame the beam, and the sixth step is to pave the bridge deck. ......

Four, the factors affecting the construction progress

1. Weather factor: the construction progress was delayed due to rain during the construction.

2. Material supply: ① The most basic supply is water and electricity supply. (2) The supply of cement, stone, sand and other materials affects ashing. (3) Gravel supply affects earthwork backfilling. ④ The supply of acetylene and oxygen affects the cutting and welding of electrical and pipeline materials. ⑤ The supply of steel bars affects the preparation of materials, thus affecting the binding of steel bars such as piers and capping beams. ⑥ The supply of iron pipes and fasteners affects scaffolder's erection of scaffolding. Pet-name ruby steel template, the supply of wood affect carpentry erection template.

3. Mechanical factors: cranes and other machinery are more important, and scaffolding and steel bars need to be hoisted by cranes. If the crane breaks down, the construction will stop.

4. Personnel factor: the number of personnel directly affects the construction speed, but too many personnel will cause manpower waste, and too few personnel will slow down the construction speed.

5. Management factors: the technical guidance of technicians and the deployment management of foremen also have great influence on the construction speed.

Five, construction safety and construction personnel safety

The factors affecting building safety are complex, besides the mutual interference and influence of many factors in the building itself, there are also technical problems, quality problems of materials and economic problems of the project. , all restrict the safety of buildings from different levels. Engineering safety is not only an engineering technical problem, but also a social and economic problem, which is closely related to people's lives and involves social and economic development and human social progress. Therefore, in every link of architectural engineering design and construction, while pursuing the economic and social benefits of the project, we must remember that safety is the eternal theme of engineering construction! Apart from architecture knowledge, what impressed us most should be security. Every construction unit has the slogan of "safety first". As an engineer, we should try our best to avoid safety accidents, not only strictly enforce the rules and regulations, but also instill safety knowledge into employees and be responsible for their life safety.

Six, the construction supervision institutions

Since 1988, China has started to implement the pilot project supervision system in the construction field, and it will be gradually implemented in five years. 1997 "Building Law of People's Republic of China (PRC)" stipulates that "the state promotes the construction project supervision system" in the form of legal system, thus making the construction project supervision enter the implementation stage nationwide. It is a major reform of China's engineering construction management system and has a far-reaching impact on China's engineering construction management. The important contents of construction project supervision are summarized as: "three controls, two controls and one coordination", which not only controls the investment, construction period and project quality of engineering construction; Carry out contract management and information management of engineering construction; Coordinate the relationship between related units.

Building products have the characteristics of great value and long service life, which are related to people's life and property safety and healthy living environment. Engineering supervision enterprises accept the entrustment of the construction unit, serve the construction unit, and supervise and manage the production process of construction projects from the perspective of product demanders. The management methods before, during and after the event are adopted to strictly supervise and inspect the quality of materials, equipment, components and components and the quality of sub-projects to ensure the engineering quality and safe use.

A more formal supervision enterprise has high personnel quality, sound enterprise management system and excellent corporate culture. Some personnel of these supervision companies are aging and have outdated knowledge, which can no longer adapt to today's supervision activities. There are also supervisors who neglect their duties. The advantage of the construction unit is that they do not seriously perform their supervision duties and do not serve the construction unit well. I believe that with the opening of the market and the perfection of the legal system, this phenomenon of non-standardization will be solved!

Seven, some contact

Touch 1: No matter whether it is cloudy or sunny, no matter how high the temperature is, the construction workers must work by the hour and in the scorching sun. Some people are still suffering from the summer heat, but their wages are not much. Someone said to me, "study hard, son!" " It's easy to make money with knowledge, so don't get tired of our death. "Yes, compared with them, our study life is a paradise! We should cherish time and study professional knowledge hard, otherwise we won't even have a chance to regret it in the future.

Touch 2: the construction unit is divided into several types of work, such as welder, carpenter, electrician, scaffolder, steel bar worker and odd jobs. During the construction, all types of work cooperate with the construction, and everyone brings out the best in each other, showing a harmonious and pleasant atmosphere.

Touching 3: The master kept teaching me knowledge when he was at the construction site, reminding me of what I should pay attention to. I thought I felt good, as if I knew everything, so I began to be careless. A webmaster asked me several questions in a row, but I didn't answer them. Those questions were clearly marked in the specification. I was scolded by him. It seems that I must get down to business. If I don't pay attention, something shameful will happen.

Touch 4: There are several female workers among all the workers, and she does no less work than men. When I asked her why she didn't do such jobs as selling clothes and cosmetics, she said, "That job makes less money, so I did it to earn more." Looking at her busy figure, I was deeply moved by her indomitable spirit. Although she is the envy of all workers, she envies me even more, because I can get more salary than her in the future and don't have to be so tired. Thinking of this, I strengthened my belief that I should study my professional knowledge well.

Eight, construction experience and feelings:

When I entered the construction site, I personally experienced some construction steps, such as ashing, leveling, steel bar bending, making stirrups, steel bar binding and rolling, measuring and setting out, elastic line and so on. Through personal construction experience, I understand that it is not easy to do any work. I watched the steel workers make steel bars lightly and quickly, but I couldn't even hold a steel bar with one hand. It seems that we must study professional knowledge seriously. Only by deeply understanding this major can we build a good bridge. If you don't touch the steel bar, you will never know how much the weight of a steel bar affects you. Without practice, we can't realize the complexity of construction.

How to distinguish whether bridge pile groups and single-row piles are multi-row or plum blossom arrangement is suitable for single pier foundation;

As the name implies, there is only one row of single-row piles, which is suitable for foundation reinforcement under steel structure or culvert load-bearing wall.

Is the bridge pile foundation reinforced?