Summary sentence of pile foundation engineering

1. The report on pile foundation construction is not clear because of your question, such as what pile foundation and the scope of the report. I can only talk to you in general terms.

Firstly, the general situation of the project is introduced. 2. Website layout and reasons; 3, equipment, personnel investment and why this arrangement; 4, the construction situation (quality, safety, schedule, find out the key and difficult points, and disclosure to the team, make plans for possible emergencies)-get to the point; 5. Safe and civilized construction; 6. What positive measures have been taken for special situations and quality and safety accidents encountered in the construction process, as well as events that directly affect the progress, and simply evaluate the consequences and impacts; 7. Whether the schedule, safety and cost have achieved the expected purpose, and the reasons for not achieving it; 8. summary.

That's about it. I will adjust myself according to the specific situation of the project, especially the outstanding things, such as process improvement, the influence of new processes and methods on the project, and the measures taken to control quality, progress and cost. I think as long as I write these clearly, I should be able to make a job with the leader.

2. Summary of the work of pile foundation technicians in building engineering Talking about the common quality problems and treatment methods of static pressure piles 1. Static pressure construction is a pile sinking technology that uses the self-weight of the pile driver and the counterweight on the frame to provide reaction force and presses the pile into the soil through the pile pressing mechanism of the static pressure driver.

Because this method has the advantages of no noise, no vibration and no impact force, it can meet the requirements of geotechnical engineering in the future. At the same time, prestressed pipe pile is generally used as the pile type, which has the characteristics of simple process, reliable quality, low cost and convenient detection. The combination of the two will greatly promote the application of static pressure pipe pile in Guangdong, and is expected to become the main product of pile foundation development in Guangdong in the future.

People have been calling for the technical specification of static pressure pile foundation for a long time, but they also hope to have a further understanding of the sinking mechanism of static pressure pile and its application in engineering practice. This paper introduces this. In the process of pile sinking, when the pile tip penetrates into the soil, the initial stress state of undisturbed soil is destroyed, which leads to the compression deformation of the soil below the pile end and the corresponding resistance of the soil to the pile end. With the increase of pile sinking pressure, when the stress on the soil at the pile tip exceeds its shear strength, the soil will deform sharply and reach the ultimate failure, and the soil will produce plastic flow (cohesive soil) or compaction, lateral displacement and downward drag (sand).

In the deep underground, due to the pressure of the overlying soil layer, the soil is mainly squeezed out in the horizontal direction around the pile, which completely destroys the soil structure near the pile. Due to the large radial pressure, the soil around the pile is also greatly disturbed. At this time, the pile body will inevitably be resisted by the friction around the pile and the resistance at the pile end caused by the strong normal resistance of soil. When the static pressure at the top of the pile is greater than these resistances, the pile will continue to penetrate and sink.

Otherwise, stop sinking. When piling, the foundation soil is strongly disturbed, and the actual shear strength of the soil around the pile is quite different from the static shear strength of the foundation soil.

With the sinking of the pile, relative shear displacement will occur between the pile and the soil around the pile. Because of the shear strength of soil and the adhesion between pile and soil, soil will produce friction on the surface around pile. When the soil around the pile is hard, the shear surface occurs on the contact surface between the pile and the soil; When the soil around the pile is soft, the shear surface generally occurs in the soil near the pile surface. With the pile sinking in cohesive soil, the shear strength of soil around the pile gradually decreases until it is reduced to remoulding strength.

In sandy soil, except loose sand, the shear strength has little change. The pile side friction acting on the pile in each soil layer is not a constant value, but a variable value that decreases significantly with the continuous sinking of the pile. Friction at the bottom of pile plays an important role in pile driving resistance, which can account for 50~80% of pile driving resistance. It is directly proportional to the strength of soil around the pile and inversely proportional to the pile depth. In cohesive soil, the compressive strength of pile tip soil is obviously reduced under the action of disturbance remodeling and excess pore water pressure.

In sandy soil, the compressive strength of dense sand decreases due to relaxation effect, while the compressive strength of loose sand increases due to compaction effect. In layered foundation, the pile tip resistance in hard soil will also be affected by the clay layer at the boundary. When the overburden is soft soil, the pile tip resistance will increase with the increase of the depth of hard soil in the critical depth range. When the underlying layer is soft soil, the pile tip resistance will decrease with the increase of hard soil within the critical thickness range.

Generally, the frictional resistance of piles is divided into three areas from top to bottom: the upper column cavity area, the middle sliding area and the lower compression area. The interval time of stopping pile pressing due to pile connection or other factors has no obvious influence on the resistance of pile tip that continues to sink, but it has a great influence on the increase of pile side friction. The increase of pile side friction is directly proportional to the length of intermittent time and related to the characteristics of foundation soil. Therefore, during static pressure pile sinking, the structure and position of pile extension should be reasonably designed to avoid pile tip staying in hard soil layer for pile extension construction.

3. After the final pressure and ultimate bearing capacity static pressure pile construction is completed, the pore water pressure in the soil begins to dissipate, the consolidation strength of the soil gradually recovers, the upper pile hole area is filled, the middle pile slip area disappears, and the pressure in the lower pile extrusion area decreases. At this time, the pile began to obtain the ultimate bearing capacity in the engineering sense. From a large number of engineering practices, the ultimate bearing capacity of long static pressure piles in cohesive soil is greater than the ultimate pressure during construction. In some soft soil areas with high consolidation coefficient, the vertical ultimate bearing capacity of single pile can be one to two times higher than the ultimate pressure. For short piles in cohesive soil, although the friction resistance is improved after a period of soil strength recovery, the proportion of side friction to the ultimate bearing capacity of the pile is not much different because of the short pile body.

Therefore, the ultimate pressure and ultimate bearing capacity of piles are two different concepts, which are often confused by designers and constructors of static pressure piles at the first contact. The two values are not necessarily equal, which are mainly related to the properties of pile length, soil around pile and soil at pile end, but also have certain relations.

Four. Frequently asked questions (1) Pile lifting Because static pressure piles are soil-squeezed piles, when there are many piles in the field and the pile spacing is relatively dense, the piles pressed in the back often squeeze and lift up the piles pressed in, especially short piles, which are easy to form so-called hanging piles. During the static load test, this kind of pile began to settle heavily and its curve was steep, but when the pile tip reached the bearing layer, its bearing capacity was obviously improved and the settlement curve tended to be flat, which was a typical pile lifting curve.

In addition to the large static load settlement, the lifting of the pile body may also break the joint, make the pile tip empty, and greatly increase the horizontal extrusion force on the surrounding piles, resulting in the inclination and deviation of the piles. In terms of treatment, the pile pressing sequence should be arranged reasonably before construction. Generally, the pile in the center of the site is pressed first, and then the surrounding piles are pressed. Pile with deep bearing stratum shall be pressed first, and pile with shallow bearing stratum shall be pressed later.

After the pile is lifted, recompression is generally used to make the pile foundation work normally, but the foundation bearing horizontal load should be careful. (II) Pile pressing by pilot hole In order to prevent excessive soil squeezing between piles, or the soil is too hard to shorten the piles, the pilot hole pile pressing technology is often used in construction, that is, first drill a hole with a diameter slightly smaller than that of the pipe pile and a depth of (2/3~ 1)L of the pile length, and then press down the pipe pile along the pre-drilled hole.

Lead holes should be pressed with lead, and the interval should not be too long, otherwise the water in the holes will soften.

3. How to write hello for the project summary? I am also engaged in engineering construction. The following are for communication only:

1 required by the superior unit must be counted when writing the summary.

2. What departments are involved in writing? All departments should cooperate with each other and write project summaries within their respective jurisdictions. Only by pooling the strength of the whole project department can we write a high-level project summary.

3. The manuscript editor must have a clear understanding of the project and the major events in the project. Generally, the draft is compiled by the engineering department or the comprehensive management department.

4. After the first draft comes out, communicate with the competent leader, analyze the whole summary from the beginning, and then modify it.

In a word, the project summary is a comprehensive and targeted document.

4. How do interns in pile foundation construction write work summaries and emphasize the importance of organization, safety, inspection and management?

There is no model essay.

The following is for reference,

Mainly write down the main work content, how to work hard and the achievements, and finally put forward some rationalization suggestions or new efforts. . . . .

Work summary is to let the superior know what contribution you have made and reflect the value of your work.

So you have to write a few points:

1, your understanding of the position and work 2, what did you do specifically?

3. How did you work hard and what things did you solve with your brain? Even if it's nothing, write something difficult. How did you solve it through hard work?

4. What abilities or knowledge do you need to improve in your future work?

5. The superior likes people who take the initiative to work. You should make all the preparations in your work, that is, the preparations in advance are as follows for your reference:

Summary is a comprehensive and systematic overall evaluation and analysis of the situation over a period of time, and analysis of achievements, shortcomings and experiences. Summary is a kind of applied writing, which is a rational thinking about the work that has been done.

Basic requirements of summary

1. Summary must have an overview and a description of the situation, some simple and some detailed.

2. Achievements and shortcomings. This is the main content of the summary. The purpose of summing up is to affirm the achievements and find out the shortcomings. What are the achievements, how big, how to use them and how to achieve them; How many shortcomings there are, what aspects they are manifested in and how they are produced should be clearly written.

3. Lessons learned. In order to facilitate the future work, we must analyze, study and summarize the previous work experience and lessons to form theoretical knowledge.

Summarize the precautions:

1. We must seek truth from facts, the achievements are basically not exaggerated, and the shortcomings are basically not narrowed. This is the basis of analysis and learning lessons.

2. Clear organization. This sentence is fluent and easy to understand.

3. Be detailed and appropriate. There are important things and minor things, so when you write, you should highlight the key points. The problems in the summary should be divided into primary and secondary, detailed.

Basic format of summary:

1, title

2. Text

Introduction: overview, overall evaluation; Summarize the full text.

Subject: analyze the shortcomings of achievements and sum up experiences and lessons.

Conclusion: Analyze the problem and make clear the direction.

Step 3 sign

Signature and date.

5. How to write a summary of engineering construction? The first thing we should do before writing is to collect on-the-spot information. "No investigation, no right to speak", if you want to write a good project summary without becoming a mere formality. It is necessary to conduct field investigation and collect real data and information. The information collected includes the following aspects: the plan and expected goal before the start of the project, the standard degree of project progress and quality, and the safety of workers' working environment. After sufficient investigation and data collection, we won't feel at a loss when writing.

The summary of engineering construction is generally divided into two parts: one is to summarize the past and analyze the problems. Make a plan to foster strengths and avoid weaknesses. Knowing the structure of engineering construction summary, we can start thinking around this.

The first part of writing can be divided into three parts: the specific situation of work, achievements and shortcomings. The writing idea of this part is to ask questions and analyze them. Different from other work summaries, it needs more accurate data to support it. Before we write, it is a necessary task to describe and record the specific work in detail. With accurate data, we can start writing. The first is the specific work situation. The specific work situation should include the specific workload, the location of the project, the situation of other units involved in the project, and the coordination with the surrounding environment of the project construction.

Secondly, the effectiveness and existing problems of writing. The effectiveness of the work should include some details in the construction process, such as the height of floor drain sealing water, the spacing of water pipe clips, the installation height of switch sockets and so on. Record the experience gained in the work in detail for future reference. Problems in work should be recorded in detail, just like effective writing, to prevent such mistakes from happening again in future work.

After analyzing the results and problems, you can write the second part of the work plan. This part of writing can't be imagined and subjective. Instead, we should make the next work plan rationally, profitably and restrainedly according to the engineering experience and actual situation.

The writing of engineering construction summary is to have an accurate reference in the future work, so authenticity and rationality are the key points of writing. In a word, as long as the authenticity and validity of the materials are guaranteed in the writing process of the project construction summary, and then a good project construction summary can be written according to the idea of asking questions, analyzing problems and solving problems.