The exam might also give you bunch of variables like “soil shear wave velocity” or “standard penetration resistance”. In actual practice, most of time, this is determined by the soil engineer. On the exam, the problem may just flat out tell you what the site class is. I've came up with three possibilities of how this can be given in a problem. S 1 is pretty similar to S S except that it’s for longer period.īy ASCE 7–05 definition, this is the “mapped MCE, 5 percent damped, spectral response acceleration parameter at a period of 1 s as defined in Section 11.4.1”.Įverything I said above for S S applies here also so I am not going to repeat it. You just have to enter site latitude and longitude which you can obtain from Google Maps by right clicking on a location and select “what’s here”. If you need to determine this number outside of the exam settings (like in your actual actual job), USGS has a handy tool that helps you determine the values for you. Otherwise, it’ll say “1.0 sec” which is the S 1 value that I’ll talk about next. If it mentions “0.2 sec” then you are looking at the S S. One thing you need to pay attention to when looking at the figures is the title. It’s good know what they look like although I’ve never had to use them. If not given, you’ll have to look at Figure 1613.5(1) to 1613.5(14) of the IBC. But as far as the exam goes, this number is usually given. If you have time, you can dig in to different seismic related books and figure out what this is all about. (IBC 2009 defines short periods as 0.2 seconds). That’s how I am going to break down these variables.īy ASCE 7–05 definition, this is the “mapped MCE, 5 percent damped, spectral response acceleration parameter at short periods as defined in Section 11.4.1”. There are “givens” and there are “things to be determined”. My recommendation: Think of “reading the code” like “solving a problem”. Now, since this part is so important, what is the best way to understand them? So if you get this part wrong, the rest of the design is essentially incorrect. This chapter of ASCE 7 is the very basic of determining the required seismic demand. It’s important to understand what these variables are and how to obtain/calculate them so that you can start on the right track. To me, ASCE 7–05 is slightly easier to read so once you get the hang of it, finding and understanding the related sections in IBC should be cake.ĭescription – Variables of “Seismic Design Criteria”Įvery lateral design problem usually starts with the variables described in Chapter 11. Note that this chapter is very closely related to Section 1613 of IBC 2009. In this post, I will start with the explanation of “ASCE 7–05 Chapter 11: Seismic Design Criteria”. If you practice structural engineering in states that rarely deal with earthquakes or if you are fairly new to the world of lateral design, I hope you find these articles helpful in your preparation for the SE exam. I understand that a lot of people in “non-earthquake areas” are not used to seismic design since it will be on the SE exam, my goal is to help you as much as possible by covering a number of important topics. Not only it’s something that we do nearly every single day, it’s also required in order to get the PE license (CA has an additional 4-hour seismic portion on top of the regular NCEES 8-hour exam for the PE exam). Since I've been practicing structural engineering in California, I've kind of taken my experience with seismic design for granted.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |