Automated inverse analysis of a deep excavation in Ankara clay using finite element analysis

Engin, Tugce Aktas
Çokça, Erdal
The objective of this study is to find out the constant that shows a linear relationship between the deformation modulus parameter of Ankara clay and SPT N-60 values by using Plaxis 2D software. During analyses, three constitutive models are used, those are Mohr-Coulomb (MC), hardening soil model (HS), and hardening soil model with small strain stiffness (HSsmall). For that purpose, reverse analysis of a 25.0-m deep excavation was done by comparing results with displacements taken from inclinometer measurements. Instead of using an idealized soil profile, soil layers are divided into 1.5-m thicknesses according to SPT N measurement depths; and for each interval, soil parameter correlation is performed. To minimize time loss, analyses were performed by writing a Python code. Finally, results were evaluated by comparing soil models with each other, and it is found out that displacement curves of the MC model could not converge to the actual displacements. Analyses results of the HSsmall model are the closest displacements to the measured values on the site. Also, displacement curves of the hardening models (HS and HSsmall) are almost similar, and the linear correlation constant is found as E-50(ref) similar to 780xN(60) kPa for this excavation of the case study in Ankara clay in HS and HSsmall models.


Optimization of the array geometry for direction finding
Özaydın, Seval; Koç, Seyit Sencer; Tanık, Yalçın; Department of Electrical and Electronics Engineering (2003)
In this thesis, optimization of the geometry of non-uniform arrays for direction finding yielding unambiguous results is studied. A measure of similarity between the array response vectors is defined. In this measure, the effects of antenna array geometry, source placements and antenna gains are included as variable parameters. Then, assuming that the antenna gains are known and constant, constraints on the similarity function are developed and described to result in unambiguous configurations and maximum r...
TANRIKULU, O; KURAN, B; Özgüven, Hasan Nevzat; IMREGUN, M (1993-07-01)
The dynamic response of multiple-degree-of-freedom nonlinear structures is usually determined by numerical integration of the equations of motion, an approach which is computationally very expensive for steady-state response analysis of large structures. In this paper, an alternative semianalytical quasilinear method based on the describing function formulation is proposed for the harmonic response analysis of structures with symmetrical nonlinearities. The equations of motion are converted to a set of nonl...
Direct numerical simulation of pipe flow using a solenoidal spectral method
Tugluk, Ozan; Tarman, Işık Hakan (2012-05-01)
In this study, a numerical method based on solenoidal basis functions, for the simulation of incompressible flow through a circular-cylindrical pipe, is presented. The solenoidal bases utilized in the study are formulated using the Legendre polynomials. Legendre polynomials are favorable, both for the form of the basis functions and for the inner product integrals arising from the Galerkin-type projection used. The projection is performed onto the dual solenoidal bases, eliminating the pressure variable, si...
Artificial-neural-network prediction of hexagonal lattice parameters for non-stoichiometric apatites
Kockan, Umit; Ozturk, Fahrettin; Evis, Zafer (2014-01-01)
In this study, hexagonal lattice parameters (a and c) and unit-cell volumes of non-stoichiometric apatites of M-10(TO4)(6)X-2 are predicted from their ionic radii with artificial neural networks. A multilayer-perceptron network is used for training. The results indicate that the Bayesian regularization method with four neurons in the hidden layer with a tansig activation function and one neuron in the output layer with a purelin function gives the best results. It is found that the errors for the predicted ...
Nonlinear flutter calculations using finite elements in a direct Eulerian-Lagrangian formulation
Seber, Guclu; Bendiksen, Oddvar O. (American Institute of Aeronautics and Astronautics (AIAA), 2008-06-01)
A fully nonlinear aeroelastic formulation of the direct Eulerian-Lagrangian computational scheme is presented in which both structural and aerodynamic nonlinearities are treated without approximations. The method is direct in the sense that the calculations are done at the finite element level, both in the fluid and structural domains, and the fluid-structure system is time-marched as a single dynamic system using a multistage Runge-Kutta scheme. The exact nonlinear boundary condition at the fluid-structure...
Citation Formats
T. A. Engin and E. Çokça, “Automated inverse analysis of a deep excavation in Ankara clay using finite element analysis,” ARABIAN JOURNAL OF GEOSCIENCES, vol. 14, no. 19, pp. 0–0, 2021, Accessed: 00, 2021. [Online]. Available: