【Life on the Construction Site】Civil Engineering University Curriculum Linkage Construction Work Series-Surveying

What kind of help the courses I took in college will help me when I enter the workplace, this is something I couldn't think of when I was studying. In this series of articles, I have written my own experience in recent years for the reference of my younger brothers and sisters.

The courses to be taken by civil engineering universities are nothing more than surveying, applied mechanics, material mechanics, structure, geodetic engineering, RC, steel structure, soil mechanics, fluid mechanics, engineering materials, construction management, construction, and pavement design. , spatial information, engineering graphics and other courses, and the work after graduation can be roughly divided into design consulting, construction plant, laboratory, construction business and other work, based on my personal experience, I have worked in construction companies and construction plants, Exactly how these disciplines can help at work, I want to try to sort them out.

Surveying and Surveying Internships

Compared with surveying, surveying internships may be more helpful for construction site work, because the most important thing for all projects before construction is to set out, so it is reasonable and unreasonable for these two courses to be ranked in the freshman year.

It is reasonable that he is the beginning of all projects, of course it is right to learn first; the unreasonable is that after four years you have forgotten all about it. I do not believe that you will remember how to operate the theodolite and level when you enter the construction site after graduation.

Professional knowledge of surveying is not so important for construction work, such as the principle of error propagation, coordinate system, aerial survey, etc., the importance is not high, what is more important is simple geometric calculation, instrument operation, use of point support Way.

In the basic terminology explanation of surveying, there are two things that are often encountered on construction sites, one is surveying and mapping, and the other is called surveying and design. The so-called surveying and mapping is the process of collecting the boundary, adjacent houses, elevation and other data of the construction site to the office, and then designing the structure; while the surveying is the process of putting the designed structure on the construction site. More emphasis is on the latter.

The theoretical basis can help you to know how to reduce the error, such as the setting of the point support, the closer the two reference points are to the right angle, the better; the use parameters of the measuring instrument, the backsight point positioning requires the angle data rather than the distance; In the height measurement class, I heard the backsight minus the frontsight and the backsight, and I heard the fog. In fact, the working hours are actually not that complicated.

Common knowledge points on construction sites

Here are a few knowledge points that are commonly used in surveying in building a house:

• Theodolite operation
• point support setting
• Elevation measurement

Theodolite operation

For the operation method of the theodolite, you can refer to this article [Life on the Construction Site] as the foundation of the project. The theodolite is set out , which details the operation process of the theodolite. In principle, the best time to use the theodolite is when excavating When making the gutters, you can ask a professional lofting company to do it at other times. I heard that the predecessors of the early construction factories all set out their own lofts. I don’t know why, in recent years, they have been subcontracted to professional manufacturers for implementation.

When I was in college, I only learned about the theodolite stand. How to draw on CAD, how to look back, and how to input the coordinates of the stakeout point, I didn’t know any of these. Even in college, I even took the test of the stand to be within a certain time value Qualified, I can only say, that means nothing at all, so I sincerely hope that the surveying practice course of the university can actually give students a drawing of a building, and ask students to stake out the building boundary points on the actual site, this is the real useful knowledge.

As for what the school won't teach you, the traditional optical theodolite will be unable to set out because you can't see the point. At this time, you need to change the point. You must choose a measuring point with a transparent field of view according to your own experience. Rather than simply racking up the instrument.

In addition, you must know the checking method. To know whether the stakeout is correct or not, you must check the length. The CAD drawing is a few meters, but the actual measurement is a few meters. There may be some errors. For example, the boundary error of a building with a total length of 50M 2CM, 2/5000=0.0004, four thousandths, it is still within the allowable error range.

point support setting

Not every site director will use a theodolite, but as the project progresses, the building boundary points are often destroyed. At this time, a point support should be set to confirm the building boundary.

The point support distance is the forward intersection method in surveying. It gives you two known points and a known distance. Taking these two known points as the center, draw a radius. The intersection of these two radii is the building you want. boundary point.

In addition, the error geometry will also be used in this knowledge point. How to set these two known points will minimize the error, you can refer to this [Construction Life] to reduce the error point support distance setting method .

The first case I just came out of the society has already built the structure on the 12th floor. On the day of entry, I was grouting. If I keep going up like this, I will not encounter the work of setting the point support. It will be two years later when a new construction site is opened. If you want to believe me, you will definitely forget everything.

Elevation measurement

The addition and subtraction of elevation measurement is a construction site calculation problem that many people make mistakes. For example, if you take the box ruler to the +50 cm baseline today, the value of the box ruler seen by the traditional level is 82 cm, and then put the box Take the ruler to the point to be measured, and see that the data on the box ruler is +100 cm at the point to be measured. What is the elevation of the point to be measured?

Believe me, even an experienced old director will make a mistake, because you don’t count this every day, you didn’t get enough sleep yesterday, secretly had a drink with the work class, or thought about your girlfriend, etc. Well, it's not your fault, it would be better for the two of you to go together, but don't let one of them be in an empty state, that's useless.

In the above question, the first thing to calculate is the height of the instrument. The instrument is 82 cm higher than the +50 baseline, so the height of the instrument is +132 cm, and the point to be measured is 100 cm below the instrument, so 132-100=32, the point to be measured The elevation is +32 cm, and so on. For details, please refer to my article [Construction Life] Level - a good helper for building a house ❘ Civil Engineering Department must learn .

The above are some knowledge points that I think are commonly used in construction sites. Others that are not used are not really useless. If you want to take some national exams, you may use them, and there is less practical help. Interested in research.

Epilogue

This is the first article in a series of articles. I will share the practical application methods of various disciplines on the construction site. However, for civil design consultants, I cannot provide relevant information. I hope that the seniors who read this article will not hesitate to provide their own. experience.

The engineering-related articles I wrote are all organized in this " Engineering Series Articles ", and will continue to be updated in the future, I hope to be helpful to you.