USGS PCMSC

Permanent Displacement Response Spectra

Index Back to home page About these web pages Conclusions Slope strength Motion studies Field parameters Compliance Abstract Compliance
Compliance is a critically important element of ground displacement
analysis for soft & liquefiable soils, soil embankments, and landfills

Photos of ground displacement.

LEFT: Text from G.K. Gilbert on the1906 event (Lawson, et al., 1908) -"There was also a horizontal shifting of mud over a considerable area", "At various places along the shore...the tidal mud seemed crowded against the firmer ground at the shore, being pushed up into a ridge" "Maximum shifting...was not less than 30 feet." MIDDLE: Liquefaction and permanennt displacement of the lower Van Norman Dam after the San Fernando Earthquake; RIGHT: Tall landfill site at southern tip of the Yodo River, Kobe region Japan.

Click on photo for enlargement (48K) (44K) (52K).
Compliant dynamic displacement analysis versus traditional rigid block (Newmark) analysis
Diagram of traditional vs multidimensional model Traditional (Newmark-type) analysis of soil displacement assumes a rigid mass shearing at its base in response to 1-D dipslope earthquake motion. Kramer & Smith (1997) extended the 1-D Newmark approach by making the mass compliant. Our model incorporates compliance and multidirectional components of earthquake motion, and block resonant motions.
Why does compliance matter in dynamic displacement analysis?

Diagrams of compliance effect and Resonance period of ground.

Traditional rigid analysis.

Flexible analysis (compliance).

geotech/spectraposter/compliance.html
contact: Robert Kayen
last modified 2019