Characterizing Permanent Deformation of Silty Sand Subgrades by Using a Model Based on Multistage Repeated-Load Triaxial Testing

Publisher's full text

A simple model for the prediction of permanent deformation of unbound pavement material was used to characterize the accumulation of permanent deformation of unsaturated silty subgrade soils from multistage repeated-load triaxial (RLT) tests. The model incorporated the time hardening concept; data obtained from RLT tests with cyclic loading of variable magnitudes, conducted on a single specimen, could be used to calibrate the material model parameters. This feature of the model allowed for characterizing the accumulation of permanent deformation of the material under a wide range of stress conditions.

The tests were carried out on two silty sand subgrades and at different moisture contents with pore suction measurements (matric suction) incorporated into the stress state calculations used in the modeling. The shakedown ranges for the permanent deformations for each stress path were calculated, and the material parameters of the predictive models were optimized with the RLT test data. In general, the models performed satisfactorily in capturing the permanent deformation behavior of the selected subgrade materials.

The model includes fewer parameters as compared with some existing permanent deformation models and requires reduced testing effort because it is based on results from a multistage RLT test with a single specimen. It can be concluded that the model and the approach have great potential for characterizing and modeling the permanent deformation of subgrade soils.



ERPUG 2017

The five year anniversary of  European Road Profile Users' Group (ERPUG) Forum will take place at Ramboll head quarter, Copenhagen, Denmark October 19-20, 2017. 

Shipping and the environment – research meets reality

Centre for Transport Studies (CTS) in co-operation with Ports of Stockholm invite you to the seminar Shipping and the environment – research meets reality.




The five-year anniversary of European Road Profile Users' Group (ERPUG) Forum will take place at Ramboll head quarter, Copenhagen, Denmark October 19-20, 2017.


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