GGSD Program Details for SHAKE91

SHAKE91

Category	Dynamics (behaviour and earthquake)
Publisher	NISEE - University of California, Berkeley
Platform	DOS
Status	Public domain
Description	SHAKE91 is a program for the equivalent linear seismic response analysis of horizontally layered soil deposits. The SHAKE program has been by far the most widely used program for computing the seismic response of horizontally layered soil deposits. The program computes the response of a semi-infinite horizontally layered soil deposit overlying a uniform half-space subjected to vertically propagating shear waves. The analysis is done in the frequency domain, and, therefore, for any set of properties, it is a linear analysis. An iterative procedure is used to account for the nonlinear behavior of the soils. The object motion (i.e., the motion that is considered to be known) can be specified at the top of any sublayer within the soil profile or at the corresponding outcrop. The main modifications incorporated in SHAKE91 include the following: The number of sublayers was increased from 20 to 50; this should permit a more accurate respresentation of deeper and/or softer soil deposits. All built-in modulus reduction and damping relationships were removed. These relationships are now specified by the user. The maximum shear velocity or the maximum modulus are now specified for each sublayer; again these are part of the input and therefore the program no longer calculates modulus values as a function of either confining pressure or shear strength. Object motion is now read from a separate file.
Cost	Free on WWW
Data formats supported	None stated
Supplier in United States of America	NISEE - University of California, Berkeley