Location

San Diego, California

Session Start Date

5-24-2010

Session End Date

5-29-2010

Abstract

Small strain shear modulus, Gmax, is a key parameter representing the small strain response of soils under seismic load. It is also an important parameter in design of foundations where only small deformation takes place. It is recognised that Gmax is significantly influenced by void ratio. The influence of void ratio on Gmax of a soil has been taken into account by using an empirical void ratio function, F(e), and various forms of F(e) have been proposed. However, each F(e) can only be applied for a given soil within a limited void ratio range. There was no available F(e) that can be applied for all soils over a wide range of void ratios. In this paper, the shear wave velocity propagating in a dry granular medium is considered as a combination of the shear wave velocity through solid particles, and the shear wave velocity through the contact network. To quantify the effect of void ratio, a dry soil element is simplified as a soil model having two phases namely the porous phase and the discontinuous-solid phase. The model suggests that the travel length of shear wave is proportional to the void ratio of the soil. Based on this, a theoretical void ratio function for small strain shear modulus, F(e) = (1+e)-3, is obtained. The theoretical function is fit well to the experimental data for both clays and sands over a wide void ratio range, and therefore can be considered as the universal void ratio function.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Meeting Name

Fifth Conference

Publisher

Missouri University of Science and Technology

Publication Date

5-24-2010

Document Version

Final Version

Rights

© 2010 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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May 24th, 12:00 AM May 29th, 12:00 AM

The Universal Void Ratio Function for Small Strain Shear Modulus

San Diego, California

Small strain shear modulus, Gmax, is a key parameter representing the small strain response of soils under seismic load. It is also an important parameter in design of foundations where only small deformation takes place. It is recognised that Gmax is significantly influenced by void ratio. The influence of void ratio on Gmax of a soil has been taken into account by using an empirical void ratio function, F(e), and various forms of F(e) have been proposed. However, each F(e) can only be applied for a given soil within a limited void ratio range. There was no available F(e) that can be applied for all soils over a wide range of void ratios. In this paper, the shear wave velocity propagating in a dry granular medium is considered as a combination of the shear wave velocity through solid particles, and the shear wave velocity through the contact network. To quantify the effect of void ratio, a dry soil element is simplified as a soil model having two phases namely the porous phase and the discontinuous-solid phase. The model suggests that the travel length of shear wave is proportional to the void ratio of the soil. Based on this, a theoretical void ratio function for small strain shear modulus, F(e) = (1+e)-3, is obtained. The theoretical function is fit well to the experimental data for both clays and sands over a wide void ratio range, and therefore can be considered as the universal void ratio function.