Evaluation method for shaking-induced volumetric strain for gravelly soils and validation by centrifuge model tests

Liquefactions of gravelly soils are widely distributed in the 2008 Wenchuan earthquake. Field investigations show that the existing settlement evaluation methods for sands are not applicable to the gravelly soils due to the gravel content effects. It is aimed to develop the evaluation method for shaking-induced volumetric strain for the gravelly soils with consideration of gravel content, which is based on the so-called "Zhang-Shamoto" model. The dynamic triaxial tests are conducted to parameterize the evaluation method, and three centrifuge model tests on the gravelly soil grounds with typical gravel contents are carried out to check the performance of the proposed evaluation method. The test results show that the higher the gravel content, the smaller the shaking-induced settlement. The proposed evaluation method can accurately predict the shaking-induced settlement for recently deposited gravelly soils, but shows a conservative prediction performance in cases with pre-shaking effects, which suggests the need to further improve the proposed evaluation method by considering the pre-shaking effects.