The Earthquake Engineering Online Archive

Effect of multi-directional shaking on liquefaction of sands

Seed, H. Bolton; Pyke, Robert M.; Martin, Geoffrey R.

UCB/EERC-75/41, Earthquake Engineering Research Center, University of California, Berkeley, 1975-12, 47 pages (475/S414/1975)

Both qualitative results of shaking table tests on dry sand and the results of a quantitative evaluation using data from cyclic simple shear tests are used to show that the shear stresses causing liquefaction under multidirectional shaking with two equal components are 10 to 20 percent less than the shear stresses causing liquefaction under one-directional shaking. Since in practice it is unlikely that a second component of motion would be equal to the single component used for design purposes, it is suggested that a reduction of 10 percent in the shear stresses causing liquefaction is a suitable general procedure for accounting for the effects of multidirectional shaking. Combining this factor with the correction factor which should be applied to cyclic triaxial test results in order to obtain the shear stresses causing liquefaction under simple shear conditions with unidirectional shaking, an overall correction factor of about 0.57 is suggested on the basis of studies conducted on normally consolidated samples of Monterey No. 0 sand.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-75-41.pdf (3 MB)