Seeing this, you may say that my teacher is rubbish.
My teacher's teacher is Lin Tongbang, and my specific teacher is a graduate student of Tianda University? Doctor, it shouldn't be rubbish.
What I said above is only for ordinary buildings. You must be very demanding of buildings like Tiananmen Square, the Great Hall of the People and the Three Gorges Dam.
Strict.
Then there is the former master, whose requirements are really strict.
When I was in the design institute, I was lucky enough to be taken by a post-50 s master for some time. I can't draw a millimeter.
Whose building has a big error in the final plastering result, even if ordinary building mortar is used to grind the surface, the error should be vertical, flat and square.
The rough spots must also be within 5 mm As for the gypsum plastering of the next layer, the requirements are higher, and the basic error should be within 2 mm..
It is not pure hooliganism to tie steel bars with plastering and pouring concrete. It must be accurate. Can you tell me when to tie the steel formwork?
How to make sure there are no mistakes? Reinforcement workers and carpenters take vernier calipers, put a steel bar and measure the distance.
First, the direction of the building is reversed. The basement is 20 cm shorter, and the two beams do not match. The third party actually measured the dislocation of the building.
I've seen one meter, and I've seen how long the balcony is 20 centimeters. The ends of the tunnel are not right. The pier is half a meter high and the pile is offset.
There are only surveyors and quality inspectors concerned in civil engineering, and there is no lower limit of accuracy.
Relatively speaking, steel structures, especially non-light steel structures, require high precision, and the parts processed in general factories have no small errors.
We saw the deviation between on-site pre-embedding and reopening.
Let me tell you a cruel fact.
At present, 70% of the technical data of the project are false, and all the opinions related to acceptance are in line with the design requirements and regulations.
Fan rules.
Even a few years ago, the third-party test report on the technical performance and parameters of concrete structure specimens and building materials could be completed after the project was completed.
Unified fraud, not objective sampling inspection during the project.
Why do I know? Because I am an employee who eats this bowl of rice. ?
Secondly, the accuracy of civil engineering only exists in the design drawings and specifications most of the time, but not in the actual construction process. What's more, a project manager who started with Chinese characters told me that there were only qualified materials and no qualified projects.
Can you imagine?
This is just the epitome of the civil engineering industry. What do you think of other industries?
However, there are exceptions to everything. The construction process of major projects is very scientific and rigorous, because we can't make mistakes and dare not make mistakes, but it is also very
Exceptions.
Lime plastering and concrete plastering are all done by the construction party with the help of workers, who can't count and don't understand. In order to save energy, some water was added. As a result,
It is a decline in strength. A construction worker stared at several dusted places, but could not see clearly what to do. The calculation destroyed the strength of the workers.
Count it in. Civil engineering materials teacher
This course has a large number of empirical formulas and a large number of experimental coefficients and constants. Theoretical derivation need not be too persistent, all are empirical formulas.
Material mechanics teacher
This course is very complicated. Not only are there a lot of constants and empirical formulas, but your formulas are also different in different places. this
This coal mine can use the formula, but the next coal mine is different.
Third, it is mainly composed of civil works and curtain walls. After the civil engineering is finished, it's time to go to the curtain wall and then go back to the construction site. Backward design drawings for civil works are 300 mm. As a curtain wall, everyone knows what 300 mm means.
The previous curtain wall design drawings were basically invalid, but fortunately the curtain wall designers approved them and returned them. The construction drawings and construction process are indeed controlled in millimeters, and the length is generally measured in millimeters at the construction site. But now
Field construction, it is impossible to be so accurate, and the national standard also requires that it be within a range, as long as it does not exceed the scope, who will return it.
It can't be said that it is an unqualified project.
Beyond the scope, it depends on experience. If it is not beyond the scope, the building will collapse and the building will not be ordinary people.
Imagine that it is so fragile, at least millions of things, so it is not so easy to go wrong. The structure has a guarantee coefficient.
Yes, it is generally considered to be 0.5-2 times the calculated value of 65438+. After the house is built, you'd better use your head if you want to knock it down. The precision required by civil engineering is a joke.
Essentially, it is a new industry. Why should we consider the industrial level of embroidery? Can you imagine that one sleeve is 2 cm longer than the other?
Fourth, it is said that cold knowledge concrete has been used for more than 100 years, but its theoretical principle is unknown, yes, it is unknown. You can understand that all concrete manufacturing and using methods are based on empirical data combined with actual measurement. I have never done industrial and civil construction, and I don't understand what the subject means by this one-millimeter-short blasting.
The roads that have been worked for so many years are mostly about roads, and the accuracy is generally for the sake of cost, such as the thickness of lime-fly ash stabilized oil and one more gong.
Except for a lot of money, the rest is as required by the specification.
I suddenly remembered something. I worked in Beijing Universal Theme Park a few years ago.
Because the owner is a foreigner, the requirements are extremely strict, and the rainwater pipe
Butt joint cannot be greater than 2mm. In this way, one day the butt joint will be greater than 2mm. Results It was found that the interface was not a flat civil part once the pipe was turned, and the accuracy of different parts was different, with an error level of 0.5-5cm. Although some of them look rough, the actual field work environment,
You have to work hard to reach the standard, and if it is not enough, you have to chisel or envelope pad.
Concrete itself is a polymer, and no matter how high the accuracy is, it is useless.
Steel structure, machinable, high precision requirements.
Geotechnical engineering, the site is constantly crawling, and the accuracy is lower.
Fifth, talk about high-speed rail piers. The deviation specification of one meter pile seems to be five centimeters. In practice, it is said that as long as it is under the pile cap.
Do it. Generally, the plastered wall is hung flat, that is, two meters square, and the verticality and flatness against the wall reach four millimeters at will, so it is qualified. Plastering essence
Degree is the highest requirement in the whole civil engineering disciplines, while decoration disciplines are another matter.
Errors must be allowed in any work. An experienced engineer will leave enough space for himself in the construction process, and sometimes he will make mistakes.
At present, it is negative difference, and sometimes only positive difference or negative difference is allowed. In the jargon of our old bricklayer, it's called counting.
There are many factors to be considered, such as which sub-items should be controlled, how to control errors, when and how to control them. We are too experienced to listen.
Some people follow the script. Someone who tells you that a building only allows a millimeter of error must be setting you up.