Rock and Soil Mechanics ›› 2021, Vol. 42 ›› Issue (4): 1078-1087.doi: 10.16285/j.rsm.2020.6227

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Experimental study on the one-dimensional nonlinear consolidation and seepage of saturated clay considering stress history under ramp loading

ZHANG Le, DANG Fa-ning, GAO Jun, DING Jiu-long   

  1. State Key Laboratory of Eco-hydraulics in Northwest Arid Region, Xi’an University of Technology, Xi'an, Shaanxi 710048, China
  • Online:2021-04-12 Published:2021-08-25
  • Contact: DANG Fa-ning, male, born in 1962, PhD, Professor, PhD supervisor, mainly engaged in the teaching and research of numerical analysis and computational mechanics of geotechnical engineering. E-mail:
  • About author:ZHANG Le, female, born in 1993, PhD candidate, specializing in clay soil mechanics and retaining wall earth pressure and geotechnical test.
  • Supported by:
    the National Natural Science Foundation of China (51979225, 51679199), the Special Funds for Public Industry Research Projects of the Ministry of Water Resources (201501034-04) and the Key Laboratory for Science and Technology Coordination & Innovation Projects of Shaanxi Province (2014SZS15-Z01).

Abstract: To study the permeability of saturated clays with different stress histories under ramp loading, the one-dimensional consolidation and seepage tests are carried out using modified GDS triaxial apparatus, and the change of the permeability coefficient of remolded silty clay in Luochuan, Shaanxi Province is studied. The results show that permeability coefficients of normally and over-consolidated saturated clays decrease nonlinearly with the increase of the consolidation stress, and the void ratios of these two soils are consistent with the trend of change of the permeability coefficients with the consolidation stress. The compressibility and permeability of soil in the overconsolidated state are much smaller than that in the normally consolidated state. The permeability coefficient and void ratio decrease with the increase of the osmotic pressure difference under a constant consolidation stress. Finally, the measured values are compared with the permeability coefficients calculated by the modified Darcy permeability coefficient formula, modified Kozeny-Carman formula, Stokes porosity permeability coefficient formula and degree of consolidation and seepage formula in Ref. [12]. The results reveal that the permeability coefficients calculated using the modified Kozeny-Carman formula are in good agreement with the measured values. Therefore, the modified Kozeny-Carman formula is recommended to predict the permeability coefficient of Luochuan saturated clay.

Key words: ramp loading, normally consolidated saturated clay, overconsolidated saturated clay, permeability coefficient, void ratio, nonlinear consolidation and seepage