What knowledge and expertise should a structural design engineer have? What is the specific work content?

Civil Engineering Visit (Understanding) Internship Report

Two days ago, the first internship of our civil engineering students began. The internship is divided into two parts: construction visit and construction experiment We will work on-site and watch videos in the studio to complete the plane, elevation and section design of primary and secondary school teaching buildings based on building codes and design principles. Through the visit and study, we gained a preliminary understanding of building construction and structural experiments, which served as a guide for our future study and practice. Now I will make a summary of the visit to the construction site and construction laboratory.

Morning: Visit the construction site of the school’s science and technology building

On Monday morning we visited the 14-story science and technology building under construction in the school. When we arrived at the gathering place, I saw that all the students were wearing engineering hats on their heads; at the same time, it was written on the doors of the living area and construction area of ??the construction site: Those who do not wear safety helmets are not allowed to enter the construction site; of course, in the science and technology building There is also a slogan written on the protective net outside the main body of the structure: Safety responsibility is more important than Mount Tai. It can be seen that the first issue to pay attention to during construction is safety. In the past, production companies did not pay attention to the safety of migrant workers, resulting in many work-related injuries and fatal accidents. These accidents caused great damage to workers and companies! At the same time, in order to ensure the smooth progress and safety of the construction, the construction site must be enclosed with brick walls. Only various construction vehicles and internal personnel can enter and exit, and our internship must also obtain their consent!

When we entered the construction area, we saw the main structure of the science and technology building at a glance. At that time, the main structure gave me the feeling that it did not look like a building and was not good-looking. This may be because it is different from the buildings I have seen that have been built and put into use. There is a large space in front of the main body. This space is used for stacking building materials. You can see that the building materials stacked are mainly steel bars. There are no building materials such as cement, sand, and stone. This is because finished concrete is now used. Time to pour the structure. This can ensure the quality of concrete, reduce construction waste and reduce production costs. In the steel bar stacking area, we can see that different types of steel bars are separated, and information such as the steel bar model and arrival time are also marked in front of them.

We followed the on-site manager upstairs. We stepped on a ladder made of steel pipes and iron mesh. We began to feel that it was very dangerous. There were steel pipes or iron bars protruding from all sides. The formwork and brackets on the second and third floors have been removed, and we can clearly see that the pillars supporting the upper weight are so large that we all feel that the floor height has become smaller. There are many structural columns around the load-bearing columns, which are used to increase the strength of the wall to prevent it from easily collapsing due to the wall being too long. Along the way, we saw that the supports for the upper floors had not yet been removed. These supports were made of steel pipes and formwork. The steel pipes were very dense, which shows that it takes a lot of support to withstand concrete slabs and beams that have no strength at all.

Up to the tenth floor, we saw that workers were still tying steel bars. The steel bars of columns and beams had been tied and placed in the slots reserved for the formwork. I observed several of the beams and columns, and it was just like what the teacher said: the lower part of the beam is the first force reinforcement, there are nine main beams, and there are six secondary beams; the upper part is not the vertical reinforcement, and the main beam and the secondary beam are different; the load-bearing reinforcement Tie with stirrups between the supporting ribs. The column is different. If three or four beams are to intersect at the column, the steel bars of the beams must pass through the columns. This makes the steel bars on the column heads very dense. At the same time, attention must be paid to the density when pouring concrete. The reinforcement of the slab generally includes load-bearing ribs and supporting ribs. The load-bearing ribs are at the bottom and are divided into vertical and horizontal directions; the supporting ribs are at the top and are also placed vertically and horizontally. The placed steel bars must be tied with wires. In order to ensure that the gluten is not stepped down, horseshoe tendons must be used to raise it. When looking at the plate reinforcements, we found that there were electrical conduits laid together with the steel bars. This is a manifestation of the cooperation between the electrical and structural professionals.

Our on-site visit time was very limited. We only saw the workers laying out the reinforcements, but we did not see them pouring columns, beams, slabs, laying brick walls and other construction scenes, so our understanding was very one-sided. This can only be used as our perceptual understanding of construction!

Afternoon: Visit the Construction Laboratory

The Construction Laboratory is a relatively old-fashioned industrial factory building that looks like a former civilian building. It is topped with prefabricated reinforced concrete traveling beams and concrete slabs. This structure is cumbersome and limits the span of the beams. It has now been replaced by the widely used rigid traveling frames and steel plates. The columns on both sides are typical industrial factory columns, with cow hooves on the upper part for installing crane tracks. Two wind-resistant columns are also erected on its wide face. These columns and beams set at regular intervals give the wall sufficient stiffness to resist strong wind loads.

The role of the laboratory is to give structural designers a place to test the feasibility of their designs. This is crucial to the safety and reliability of the building, and is also necessary for scientific experiments. .

In the laboratory, we have seen many large-scale experimental instruments, which essentially provide compression, tension, and shear stress to the specimen to test its ability to withstand stress, that is, they intensity.

The structural components (usually columns, beams, plates, and of course piles) are hoisted to the experimental machine tool by a crane, and then loads are applied to the components, and relevant information on stress and deformation is collected through sensors installed in the components. Pass it to the relevant instruments, and the experimenter can record the data and analyze and process it to get the results!

In the laboratory, we can also see models of various components. Among them are steel strands for making piles and sleeves for tightening the steel strands.

Of course, we not only looked at various machines and understood their basic uses and methods of use, but also had a preliminary understanding of construction experiments and established a concept of experimentally testing hypotheses. This visit should be quite fruitful.

The morning of the second day: watching construction-related videos

Through the on-site visit the day before, we had a general perceptual understanding of the building, but we were not familiar with the construction process and some details. We know relatively little about the problems and possible dangers. Through the form of documentary, we can understand and learn from the overall breadth.

We watched the construction process of the xxx building, which was once the tallest building in the country. From the video, we saw the construction process of reinforced concrete structure buildings, and also saw relatively advanced construction and production technologies, such as: pumps Concrete pouring methods and efficient formwork technology, etc. The application of these technologies in production has brought high efficiency to production.

In the second video, we saw the most serious natural disaster on earth - the damage caused by earthquakes to people's lives and property. Of course, apart from human lives, the buildings that are most damaged by earthquakes are buildings. Whenever an earthquake hits a city, thousands of buildings will be destroyed. The city after the earthquake will be devastated. The streets and buildings we are used to are all gone, which is very harmful to our spirit.

Those old houses that have not undergone any earthquake-resistant treatment are easily destroyed in an earthquake. This seems to be a matter of course, because most of these houses are masonry structures or brick-concrete structures. The seismic performance of this structure is very poor and can hardly withstand earthquakes. However, some buildings with reinforced concrete frame structures are not immune to earthquakes - of course, in these cases, the environment in which the building is located and the relationship between its natural frequency and earthquake frequency must be studied - but the reason is often that the stress on these building structures irrationality.

In the 1980s and 1990s, many new technical solutions were researched and developed to enhance the seismic performance of reinforced concrete high-rise buildings. Structural engineers believed that these new technical solutions could make the buildings more effective. To withstand earthquake attacks, the results were unfortunate. One after another, high-rise buildings collapsed during earthquakes. Even stronger viaduct structures frequently collapsed during earthquakes, which panicked structural engineers around the world.

We still cannot clearly understand the activity of earthquakes and do not know when they will occur. But even if we can predict them before earthquakes, it only increases the hope of people's escape and has no effect on buildings. If we can't predict them quickly, Without properly solving the problem of the harmful effects of earthquake vibrations on the building structure itself, our buildings will have no power to resist and can only sit and wait for death.

Fortunately, with the widespread use of steel structures, structural engineers discovered that although many reinforced concrete buildings designed to be highly resistant to earthquakes collapsed in strong earthquakes, none of the steel structure high-rise buildings appeared over collapse phenomenon. This is enough to illustrate the advantages of steel structure buildings in surviving earthquakes, and also brings hope to countries or regions with frequent seismic activities. They can reduce the number of houses caused by earthquakes by building less or no reinforced concrete structures and only building steel structures. Losses caused by earthquakes. This is the case in both Japan and Taiwan. In Taiwan, even several-story teaching buildings now have steel structures.

Although reinforced concrete structures are not favored in areas with frequent earthquakes, there are still many in China, especially in mainland China. Take Guangzhou as an example. Every year, many high-rise and even super-high-rise buildings are built in Guangzhou. Most of these buildings are reinforced concrete structures. I can’t say whether it’s good or bad, but if an earthquake really happens, the citizens of Guangzhou will suffer. The population is densely populated and people live in houses that are easily damaged. The consequences are hard to imagine!