Development and evaluation of a practical nonlinear elastic constitutive model for rockfill dam deformation simulation based on monitoring results

To appropriately connect good simulation of rockfill material stress-strain behavior at element level with good simulation of dam deformation, a practical nonlinear elastic EBD constitutive model is developed by introducing dilatancy into the traditional Duncan-Chang EB model. Based on the dam deformation monitoring data of the 164.8 m high Aertashi concrete face rockfill dam and particle swarm optimization, five inversion cases are designed to obtain the optimal EB and EBD model parameters that achieve the best fit with monitoring data. The traditional EB model is shown to have difficulties in achieving good simulation for both settlement and horizontal displacement of rockfill dams, especially in terms of their distribution, whereas the EBD model can simulate both settlement and horizontal displacement well. More importantly, the EB model parameters that allow for acceptable simulation of dam deformation result in poor simulation of element level stress-strain behavior of the gravelly sand, rockfill, and overburden materials. In contrast, the EBD model can achieve good simulation of dam deformation and element level stress-strain behavior simultaneously, paving the way for accurate dam deformation prediction based on model parameters calibrated via triaxial tests.

Automated summary

A practical nonlinear elastic EBD constitutive model is developed to connect the stress-strain behavior of rockfill material with dam deformation. The traditional EB model has difficulties in simulating settlement and horizontal displacement of rockfill dams, whereas the EBD model can simulate both well. Moreover, the EB model parameters that achieve acceptable simulation of dam deformation result in poor simulation of element level stress-strain behavior, whereas the EBD model can achieve good simulation of both dam deformation and element level stress-strain behavior simultaneously.