The influence of undrained cyclic loading patterns and consolidation states on the deformation features of saturated fine sand over a wide strain range
| Autor: | Zhou Zheng-long, Sun Tian, Pan Hua, Li Xiaojun, Chen Guo-xing |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
021110 strategic
defence & security studies Damping ratio Materials science Consolidation (soil) Hollow cylinder 0211 other engineering and technologies Geology 02 engineering and technology Geotechnical Engineering and Engineering Geology Shear modulus Close relationship Shear stress Relative density Cyclic loading Geotechnical engineering Composite material 021101 geological & geomatics engineering |
| Zdroj: | Engineering Geology. 204:77-93 |
| ISSN: | 0013-7952 |
| DOI: | 10.1016/j.enggeo.2016.02.008 |
| Popis: | Undrained cyclic loading patterns and consolidation states can significantly affect the deformation features of medium-dense saturated fine-grained sand. A series of undrained cyclic loading tests with different consolidation states, i.e., various mean effective consolidation stresses ( p 0 ), principal stress direction angles ( α 0 ), ratios ( R 0 ) of major and minor principal stresses, and relative magnitudes of intermediate principal stress ( b 0 ), were performed on saturated micaceous fine sand specimens with a relative density of 50% corresponding to a wide strain range in the order of 10 − 5 to 10 − 2 . The patterns of cyclic axial, torsional, and axial–torsional combined loadings were applied in a hollow cylinder apparatus. The small-strain shear modulus G 0 , the reference shear strain γ r , curves for shear modulus reduction G / G 0 , the damping ratio λ and Poisson's ratio υ with increasing strain were determined. The results of the cyclic axial–torsional combined tests showed a close relationship between G 0 , γ r , and υ as well as the consolidation state parameters p 0 , R 0 , α 0 , and b 0 . The G 0 and γ r increased nearly linearly with increasing p 0 and with decreasing α 0 or b 0 . The υ is strain dependent and increases as the p 0 decreases. Tests indicated that the reduction of G with increasing shear strain γ became more pronounced as p 0 increased. The relationship for the G / G 0 versus γ / γ r was approximately independent of the cyclic loading patterns and the various values of parameters p 0 , R 0 , α 0 , and b 0 . A slight difference is noted between the damping ratios λ t and λ z , corresponding to vertical and torsional deformations. An empirical model was proposed for the dependence of the increase in damping ratio characteristics on the deviatoric strain. |
| Databáze: | OpenAIRE |
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