Amirkabir University of TechnologyAmirkabir Journal of Civil Engineering2588-297X541120230121Effect of uncertainty of soil parameters on the dynamic response of soil using random field theoryEffect of uncertainty of soil parameters on the dynamic response of soil using random field theory41894204485010.22060/ceej.2022.20229.7372FAHasanNikpoorMSc student, Department of Civil Engineering, Shahrood University of Technology, Shahrood, IranAmirBazrafshan MoghaddamAssistant professor, Department of Civil Engineering, Shahrood University of TechnologyJournal Article20210703<span style="letter-spacing: .05pt;">Seismic waves caused by earthquakes undergo many changes when passing through different layers of soil. For this reason, the effects of soil parameters on the dynamic response of the ground should be considered. The parameters in a heterogeneous soil layer are affected by a set of uncertainties, which in this research is the inherent variability of the soil shear modulus parameter. In this research, using random field theory and finite difference method in the framework of Monte Carlo simulations, the effect of two-dimensional spatial variability of the soil shear modulus parameter on the magnification factor of the maximum ground acceleration and the surface acceleration response spectrum has been investigated. In the conventional deterministic analysis, only a constant value of the average shear modulus is considered in the dynamic model, but in the stochastic analysis, the parameter of the soil shear modulus is considered as a random variable. The results obtained from the analysis show that with the increase of heterogeneity and changes in the shear modulus of the soil, the values of the magnification factor of the maximum ground acceleration decrease. Also, with the increase in the coefficient of variation of the soil shear modulus and as a result of the increase in the heterogeneity of the soil profile, the acceleration response spectrum of the surface of the soil profile obtained from random analyzes decreases.</span><span style="letter-spacing: .05pt;">Seismic waves caused by earthquakes undergo many changes when passing through different layers of soil. For this reason, the effects of soil parameters on the dynamic response of the ground should be considered. The parameters in a heterogeneous soil layer are affected by a set of uncertainties, which in this research is the inherent variability of the soil shear modulus parameter. In this research, using random field theory and finite difference method in the framework of Monte Carlo simulations, the effect of two-dimensional spatial variability of the soil shear modulus parameter on the magnification factor of the maximum ground acceleration and the surface acceleration response spectrum has been investigated. In the conventional deterministic analysis, only a constant value of the average shear modulus is considered in the dynamic model, but in the stochastic analysis, the parameter of the soil shear modulus is considered as a random variable. The results obtained from the analysis show that with the increase of heterogeneity and changes in the shear modulus of the soil, the values of the magnification factor of the maximum ground acceleration decrease. Also, with the increase in the coefficient of variation of the soil shear modulus and as a result of the increase in the heterogeneity of the soil profile, the acceleration response spectrum of the surface of the soil profile obtained from random analyzes decreases.</span>https://ceej.aut.ac.ir/article_4850_60f3e3c2c36caa402283fe458c81cd1e.pdf