000018391 001__ 18391
000018391 005__ 20170118182220.0
000018391 04107 $$aeng
000018391 046__ $$k2017-01-09
000018391 100__ $$aKumar, Abhishek
000018391 24500 $$aEffects of Earthquake Motion and Overburden Thickness on Strain Behavior of Clay and Sandy Soil

000018391 24630 $$n16.$$pProceedings of the 16th World Conference on Earthquake Engineering
000018391 260__ $$b
000018391 506__ $$arestricted
000018391 520__ $$2eng$$aEffects of earthquakes (EQs) are not limited only to the epicentral region. Depending on the magnitude of the EQ and the frequency content of input motion, the damages can be widespread. The amplitude, duration and frequency content of input motion at a site further changes due to the presence of in-situ soil at the site. Thus, similar to the determination of regional seismic hazard, quantification of local site effect is equally important. Dynamic soil properties which determine the behavior of local soil under EQ loading are not readily available on regional level. Hence, standard dynamic soil properties curves developed for other regions are used for a large number of studies. In the present work, response of two soil columns consisting of clay and sand alone throughout the depth, are analyzed using equivalent linear method using 30 worldwide recorded ground motions. Based on the present analysis, two important conclusions are drawn. It is well established fact that in equivalent linear analysis, the response of soil is governed by one value of strain. First conclusion suggests that understanding equivalent linear response of same soil collectively during various recorded ground motions covering a wide range of ground motion parameters, complete nonlinear soil behavior can be understood. In such case each ground motion will provide dynamic soil properties corresponding to specific level of strain. As a second conclusion, it is found that this strain developed in the soil during each ground motion is a function of peak horizontal acceleration (PHA) of input motion as well as the thickness of overburden. Further, this strain governs the soil behavior during that particular ground motion. Thus, if this value of strain is known, the response of the soil can be determined based on one value of shear modulus and damping ratio avoiding iterative procedure. Based on the above analyses, two empirical correlations are proposed in this work, correlating above value of strain in a soil layer with the PHA of input ground motion as well as overburden thickness above the soil layer. Overburden thickness is used in place of overburden pressure since it is used in available ground response models while determining the value of strains. Knowing the PHA from seismic hazard study and overburden thickness from soil investigation, one value of strain can be estimated based on proposed correlation. The behavior of soil will be governed by this value of strain alone and thus considering complete nonlinear soil behavior may not be needed. It has to be highlighted here that the present work uses two hypothetical soil columns of sand and clay respectively to provide a general idea about the above two conclusions. For case specific correlations however, similar works can be attempted in the future.

000018391 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000018391 653__ $$aLocal site effects, dynamic soil properties, input motion, overburden thickness, strains.

000018391 7112_ $$a16th World Conference on Earthquake Engineering$$cSantiago (CL)$$d2017-01-09 / 2017-01-13$$gWCEE16
000018391 720__ $$aKumar, Abhishek$$iBaro, Olympa$$iHarinarayan, Nh
000018391 8560_ $$ffischerc@itam.cas.cz
000018391 8564_ $$s329534$$uhttps://invenio.itam.cas.cz/record/18391/files/1361.pdf$$yOriginal version of the author's contribution as presented on USB, paper 1361.
000018391 962__ $$r16048
000018391 980__ $$aPAPER