CE 147 - 03 2006 IBC Seismic Loads

CE 147 - 03 2006 IBC Seismic Loads - Estimating Earthquake...

Info icon This preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Estimating Earthquake Demands Using the 2006 International Building Code (IBC) Introduction Establishing seismic loads using the 2006 IBC requires both 2006 IBC (Chapter 16) 2005 ASCE 7 ( Minimum Design Loads for Buildings and Other Structures ) (Chapters 11 and 12) Unfortunately, the requirement to use both 2006 IBC and 2005 ASCE 7 is not very “user friendly” but that’s life… These notes attempt to organize the process of establishing the seismic demand and contain the relevant material from ASCE 7
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
2 These notes are a brief summary. To fully appreciate the meaning of ifi i t f t t l ti i ASCE 7 d th IBC Introduction specific requirements, refer to actual sections in ASCE 7 and the IBC. IBC Section 1613 (Earthquake Loads) ASCE 7 Ch.11: Seismic Design Criteria Ch. 18: Damping Systems Ch. 12: Seismic Design Requirements Ch. 19: Soil-Structure Interaction Ch 13: Nonstructural Seismic Design Ch 20: Site Classifications Procedure Most relevant to this class Ch. 13: Nonstructural Seismic Design Ch. 20: Site Classifications Procedure Ch. 14: Material Specific Design Requirements Ch. 21: Site-Specific Ground Motion Procedure Ch. 15: Nonbuilding Structures Ch. 22: Ground Motion and T L Maps Ch. 16: Seismic Response (time history) Ch. 23: Seismic References Ch. 17: Seismically Isolated Structures Variety of methods that can be used to estimate earthquake loads Index Force Method (not used) Analytical Methods Simplified Analysis (only applicable to very simple structures) Equivalent Lateral Force (ELF) Analysis (most structures) Modal Response Spectrum Analysis (more complex situations or tall structures – fairly common) Linear Response Time History Analysis (hardly ever used) Nonlinear Response History Analysis (used for very complex structures)
Image of page 2
3 The Index Force, Simplified Analysis, and ELF methods “pretend” that seismic forces can be represented by loads applied TO the Analytical Methods building In reality, seismic loads are inertial loads (i.e. they are caused by the inertial resistance of the building to being displaced as the ground moves) “Applied” forces “Inertial” forces Equivalent Lateral Force Inertial Force due to Ground Movement Base Shear Force (‘reaction”) Force displacing ground This is more of a theoretical difference than a practical difference, but it is important to understand that there isn’t a “big hand” Analytical Methods pushing the building over. The other methods reflect the dynamic response of the structure in obtaining the seismic loads and are, therefore, more theoretically sound.
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
4 How do you decide what “size” earthquake should be used for design? Probability Considerations Current approach tries to define an earthquake with a specified probability of occurrence. Smaller earthquakes are more likely to occur over a given length of time and larger earthquakes are less likely to occur Example: On the average, which length of time will have the l t th k i 1 d i d 50 i d? largest earthquake occurring: a 1-day period or a 50-year period?
Image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern