Modeling cyclic behavior of geosynthetics using mathematical functions combined with Masing rule and bounding surface plasticity

摘要

In the numerical analysis of geosynthetic-reinforced soil structures subjected tonearthquake loadings, the constitutive model for the geosynthetic reinforcement is important, becausenit affects the accuracy of numerical simulations. Two different approaches for modeling thenmonotonic and cyclic behavior of geosynthetic reinforcements are discussed in this paper: annonlinear mathematical function combined with the modified Masing rule, and bounding surfacenplasticity. The Masing rule was modified so that it can simulate the hysteretic behavior ofngeosynthetics under cyclic loading, including the decrease in the residual strain rate with thennumber of loading cycles (cyclic strain-hardening). For the bounding surface model, differentnbounding lines were defined for primary loading, unloading, and reloading. An exponential functionnwas used as the bounding line for primary loading in order to capture the stiffening behavior ofnsome geosynthetics. Constitutive models were proposed based on the two approaches for differentntypes of geosynthetic. Experimental results for six geogrids were used to verify the proposednmodels, and it was shown that they were able to capture the nonlinear and hysteretic behavior ofnthe corresponding geosynthetics. It was shown that the approach utilizing a mathematical functionncombined with the modified Masing rule is simple and straightforward. Bounding surface plasticitynprovides an approach that is more rational for simulating the cyclic behavior of geosynthetics,nespecially for the case of irregular earthquake loading.