Civil Engineering Association

Sigma: Issues, Insights, and Challenges

Assessing the variability of ground motions, σ, is an inescapable reality in the ground-motion prediction process, since the appropriate characterization of ground motions needs to acknowledge the large degree of scatter associated with these motions. The value of σ has remained fairly stable over the past 40 years, with values typically lying between 0.10 and 0.40 log10 units (about 0.23 to 0.92 ln units) and most commonly falling in the range of 0.15 to 0.35 log10 units (0.35 to 0.80 ln units). The resistance of σ to any efforts made to reduce its value is a matter of great concern to ground-motion prediction in general and seismic hazard analysis in particular, in view of the significant impact the value of σ has on hazard estimates. This impact has sometimes led to the temptation of ignoring σ altogether, but it is now accepted that the inclusion of σ, rather than being an option that can be switched on and off, is an integral part of any seismic hazard assessment process.

Code:
***************************************

Content of this section is hidden, You must be registered and activate your account to see this content. See this link to read how you can remove this limitation:

http://forum.civilea.com/thread-27464.html

***************************************

as per requested by Iceman84

This post has been made by CivilEA Post-Generator ver 2.1.6

Sumatra