Performance Analysis

[statikçim]

Hello. There is an existing structure. There is no elevator in this building. An elevator will be built, so the municipality wants a performance analysis. Even if the elevator will not be built, performance analysis is required according to the results below. Core and stripping reports were issued. The building is 15 years old. The average concrete value is C14.6. I would like to ask your forgiveness, how should the performance analysis be done for this structure? I watched the video of ide on this subject, so I have time to try it for the first time. I want you to help. I only have concrete class and x-ray reinforcements from 2 columns and 1 curtain on each floor, but there is no information about beams. What other values are needed? I ask experienced people to explain the steps I need to follow? Have a good works

 

[NYILMAZ]

X-rays alone are not enough. For reinforcement, you need to scrape and strip the concrete cover from both columns and beams. As a result of this stripping, you should see the diameter, gap conditions, corrosion and denaturing (ribbed, flat) information of the reinforcements. You should see the closure of the stirrups (135, 90 degrees). The number of samples to be taken and the number of elements to be stripped are written in the regulation depending on the level of knowledge. The regulation on core results requires the mean - standard deviation value, not the mean.

 

[statikçim]

Thank you for your reply. Today I received the entire static project of the relevant building. It was built in 2000. so it's not 15 but 18 years old. in the project it says concrete class Bs 16 and steel class Bc I. BUILDING B+Z+A+4 FLOOR, 3 CORE BOARDS ARE TAKEN FROM EACH FLOOR, THE STRENGTH OF EACH ONE IS DETERMINED. CAN I MAKE A PERFORMANCE ANALYSIS WITH THE EXISTING PROJECT OF THE BUILDING BECAUSE THE X-RAY AND SCRAPING WAS DONE BUT IT IS NOT CLEAR. I don't know if I could explain my problem, my aim is to analyze the project at hand and learn its performance. If the majority does not save, they do not accept to strengthen anyway. They want to tear it down and rebuild it.

 

[NYILMAZ]

The project in your hand will help you to model the structure easily. Other than that, you shouldn't rely on too many projects. You can only check whether the column beams are in place according to the project and whether their dimensions are correct. It doesn't matter what the reinforcement class is in that project. I recommend that you see the reinforcements in the reinforcement stripping on site for yourself.

 

[unver]

Hello My Suggestions

I don't know if I could explain my problem. My aim is to analyze the project and learn its performance. If it doesn't save the majority, they don't agree to retrofit anyway. They want to demolish it and rebuild it.

If this is the case, your job becomes easier.

Regulation on core results requires the mean - standard deviation value, not the mean.

Find the concrete values as Nedim said,

Today, the entire static project of the structure related to my hand It was built in 2000. That is, it is an 18-year-old building, not 15. In the project, it says concrete class Bs 16 and steel class Bc I.

Enter the X-ray values of the existing reinforcement, the reinforcements of the existing structure, (don't trust the project, either, some reinforcement reduction and corrosion It's possible that it was made without supervision. ) Have a performance account and see the situation, I guess, because the concrete and iron values are low, don't worry. it will not. Continue until you recover the performance calculation by adding curtains to the building. (Don't forget the under-the-scenes basics.) This gives you an idea of whether retrofitting will be economical. If it is not economical, you say it should be destroyed. (If you do not have experience in this matter, get support from an experienced colleague.) If you decide that it can be economical;

Only X-ray is not enough. For reinforcement, you need to scrape and strip the concrete cover from both columns and beams. As a result of this stripping, you should see the diameter, gap conditions, corrosion and denaturing quality (ribbed, flat) information of the reinforcements. You should see the closure of the stirrups (135, 90 degrees). The number of samples to be taken is written in the regulation depending on the level of knowledge of the number of elements to be stripped.

You can also determine the situations that Nedim emphasized in the earthquake regulation, record them in the report and make a performance calculation again according to these values. Unver OZCAN

 

[statikçim]

Thank you one by one for your answers. According to TDY2007 7.2.2, my building is in the category of comprehensive knowledge, isn't it? I calculate it from the item 7.2.6.3. When I calculate the average-standard deviation value for each floor in the core results, -For the basement floor: 7.33 N/mm2 -For the ground floor: 6.53 N/mm2 -For the mezzanine floor: 9.11 N/mm2 value goes down. Is analysis possible under these conditions? The core test results are as follows: only the stripping photos and x-ray results of the reinforcements are available. that is, the samples were taken and their yield and rupture strengths were not determined. ribbed and diameter information is available. As a result of reinforcement stripping, corrosion is almost zero, so the reinforcements are clean. How should I go about the accessories? Should I design according to the current project and make a certain reduction in intervals and quantities, assuming that there is no control? that is, if the concrete class is as I have calculated above, even if the reinforcements are perfect according to the project, reinforcement will be required, but I am waiting for your suggestions and support. have a good day...

 

[statikçim]

Can you help me?

 

[NYILMAZ]

The level of knowledge about your structure is Intermediate Knowledge Level. There can be no comprehensive level of knowledge. Finding his project does not mean that you have obtained comprehensive information. If the control mechanisms are in place, if the reviews are complete and with a project, then maybe you can call it comprehensive. Even then, it's still debatable. However, your structure dates back to about 20 years ago. It's unclear how he did it. Therefore, it is necessary to take an intermediate level of knowledge and accordingly, you must fulfill the requirements in article 7.2.5. I can say this about the reports. Although the laboratories give some results, you should evaluate them as an engineer, since the workers there are technicians or unqualified personnel. I think just trust the concrete quality test. Observe others yourself. Check if the reduction coefficients are applied in the core results. If it is not implemented, you need to make a table about it. I am attaching an example. There is no need for any test or value for the reinforcement values (yield / rupture). You enter the values you observe with stripping the reinforcement. You may not see the corrosions on the stripped points. In this case, observe the building in general. Corrosion may occur due to leaks, especially in wet areas. Stripping in this area is often difficult. Therefore, you cannot observe. If there is a basement floor, there is a possibility of corrosion in those areas. The building, for which a decision for reinforcement or demolition should be made, is evaluated according to the case that the value obtained as a result of the ratio of the cost calculated within the scope of the retrofitting project to the cost of rebuilding the building in question is not lower than 0.40. This 40% value is general convention. However, studies involving more comprehensive evaluations in which cost-benefit analyzes are made about making an economic evaluation regarding this decision should be conducted. Another evaluation regarding whether reinforcement will be made is the concrete quality. If the concrete quality is 6.0 MPa or less, it can be concluded that direct reinforcement will be very costly and not necessary. Of course, these are all things based on certain experiences. The property of the building, its life, many issues become important in making these decisions. N. YILMAZ

 

[statikçim]

Thank you

Check if the reduction coefficients are applied in the core results. If not, you need to make a table about it. I give an example in the appendix N. YILMAZ

You said that the reduction coefficient in the core results is medium knowledge level Did we multiply it by the square of 0.85. So is this coefficient clear in the regulation? Table 7.1 I saw the information level coefficient for buildings, but I guess it's not. As a result, if I calculate this with x0.85x0.85 as in your example, the concrete calculation value is 6.93 N/mm2 I'm thinking of modeling and analyzing according to this value. I want to ask the following for the last time before I start - will I check the modeling of the construction from the static project and building in my hand and enter Idecad as if I were doing a normal static project? You said, "How should I observe the reinforcements myself? - Let's say I observed the corrosions and some in the basement." If I have detected r corrosion, how do I enter it into the system? In the old versions, when the column and beam properties were entered, there was a corrosion factor in the static/reinforced concrete tab, but I could not find it in the current 8.62 version. Thank you very much, I wish you a good day

 

[unver]

In old versions, when column and beam properties were entered, there was a corrosion factor in the static/reinforced concrete tab, but I could not find it in the current 8.62 version.

Point to column or beam, right click and enter properties.

 

[NYILMAZ]

Thank you, did we multiply the reduction coefficient in the core results with the square of 0.85 for the medium level of information. So is the value of this coefficient clear in the regulation? Table 7.1 I saw the information level coefficient for buildings, but I guess it's not. [ /quote] Reductions here mean fconcrete = 0.85 *f core average ________ (0.85 ) Reduction Coefficient fcm = 0.85 * fbeton __________________ (0.85) Cube to Cylinder Conversion Coefficient

-Will I enter idecad as if I would do a normal static project by checking the modeling of the production from the static project and building in my hand?

Of course, you can use the project you have. However, you should be sure whether the reinforcements are placed in accordance with the project, especially the tightening of stirrups in column-beam junctions, etc., how much harmony is achieved between the on-site and the project. Then you can analyze accordingly.

-"I think you just trust the concrete quality test. Observe the others yourself." How should I observe the reinforcement myself?

The answer I gave above answers this question as well. Observe the reinforcements from critical points. Look at the compatibility of the beam reinforcements. Real x-ray and stripping usually give an idea about the column reinforcements. It is not enough on its own.

-let's say I observed corrosion and if I detected some corrosion in the basement, how do I enter it into the system. In the old versions, when the column and beam properties were entered, there was a corrosion factor in the static/reinforced concrete tab, but I could not find it in the current 8.62 version. Thank you very much, I wish you a good day

Please see the attached pictures. After all, I would like to say that the interpretation of performance analysis results requires a separate experience. N. YILMAZ

 

[statikçim]

thank you very much for your help.

Reductions here mean fbeton = 0.85 *f core average ________ (0.85 ) Reduction Coefficient fcm = 0.85 * fbeton __________________ (0.85) Cube to Cylinder Conversion Coefficient N. YILMAZ

here my cores are already cylindrical, so I will only use 0.85 reduction coefficient, right?

 

[statikçim]

While performing performance analysis, we do not need to enter the R coefficient and the soil safety stress, right? I made an analysis, calculated the concrete value as Nedim said, only applied the 0.85 reduction coefficient and the value was 8.16 Mpa. I modeled the construction and made the analysis according to this value. As a result, collapse occurred in all directions. I'm adding the project, I would be glad if you help me and tell me my mistakes and comments.

You do not have permission to view link Log in or register now.

 

[statikçim]

Is there anyone to help?

 

[NYILMAZ]

First of all, I can't say anything about the targeted performance level because I don't know what the structure is. According to the data you entered, if your structure is one of cinemas, theaters, concert halls, cultural centers, sports facilities or residences, workplaces, hotels, touristic facilities, industrial structures, etc., you can select the life safety performance level. Secondly, as far as I can see, you have chosen to use a different concrete quality for floors and foundations. Although we do not consider floors as load-bearing elements, you should use the concrete values that you get from the floors and that you use on the basis of building elements for the whole structure. Although there is no statement about the foundations of the building in the performance analysis topics in chapter 7 of the earthquake code, soil parameters are important in the analysis of the building. Ground dominant period, characteristic periods will affect the behavior of the structure. I don't know how you determined the column and beam reinforcements. Did you enter the reinforcements that appear in the column, beam, curtain dialogs or did the program calculate it?

 

[statikçim]

First of all, I can't say anything about the targeted performance level because I don't know what the structure of the building is. According to the data you entered, your building will be from cinemas, theaters, concert halls, cultural centers, sports facilities or residences, workplaces, hotels, You can choose the life safety performance level if it is one of touristic facilities, industrial buildings, etc.

Construction downstairs store upper floors office where do I choose it

Secondly, as far as I can see, you have chosen a different concrete quality for floors and foundations. Although Although we do not consider floors as load-bearing elements, you should use the concrete values you get from the floors and use on the basis of building elements for the entire structure.

Although do the performance analysis topics in chapter 7 of earthquake code Although there is no statement about the foundations of the building, soil parameters are important in the analysis of the structure. Ground dominant period, characteristic periods will affect the behavior of the structure.

I don't know the ground safety value, it's the estimated value I used in the calculation. that is, the ground class is certain z3 but the ground safety stress is not certain, do I need to enter it?

I don't know how you determined the column and beam reinforcements. Did you enter the reinforcements that appear in the column, beam and curtain dialogs or did the program calculate it?

Yes, the values determined by the program itself. I just chose the diameters of the carrier elements from the reinforcement selection. But I didn't make any edits. So these are the program's own hash. As a result, I would like to say the following: If the equipment will not save even at these values, I did not feel the need to make any adjustments so that it would not save if it was minimized in its current state. If the collapse of the construction is inevitable due to the concrete value, we will say that the structure should either be demolished and rebuilt or strengthened. The owner of the building is also not very close to strengthening. So if reinforcement is needed it won't do it at all. He'll probably want to destroy it. Do you think my concrete value calculation was correct? I did it with the example calculation you sent, I only applied the 0.85 reduction factor. I did not apply the transformation coefficient to the cylinder.

 

[statikçim]

Mr. Nedim, I am aware that I asked a lot of questions, your help pleased me. I will be happy if you answer my last questions. Thanks