About the authors
| First name, Middle name, Last name, Scientific degree, Scientific rank, Current position. Full and brief name of the organization, The organization address. | Hani M. A. Sharaf, Candidate of Technical Sciences, Senior Lecturer, Kazan State University of Architecture and Engineering, Kazan, Russian Federation E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it , ORCID: 0000-0001-9755-965X |
| Title of the article | Drained and undrained soil loading conditions within the finite element method |
| Abstract. | Problem statement. A correct assessment of the bearing capacity and stability of geotechnical structures requires separate analysis of their behavior in the short-term and long-term perspectives. This distinction is fundamental due to the different responses of saturated soils under rapid and slow loading, which are related to the generation and dissipation of pore water pressure. The methodology involves sequential numerical modeling of drained and undrained loading of a clay soil specimen under triaxial compression conditions. The objective of the study is to demonstrate the finite element method for simulating soil behavior under both drained and undrained loading using effective stress principles. The tasks of this research are to parameterize and verify the Cam Clay model using hypothetical laboratory data and numerical coupled deformation-seepage analysis, demonstrating that differences between drained and undrained soil behavior are determined by drainage conditions and loading rate, rather than by changes in the material model; and to compare the modeling results obtained in Abaqus, Plaxis 2D, and Helwany data with hypothetical experimental results to assess the adequacy of the applied approach. Results: The finite element modeling results demonstrate excellent agreement with hypothetical experimental data, confirming the adequacy of the selected models and the effective stress–based approach. It is shown that the key factor governing soil behavior is the rate of load application relative to the rate of filtration. Under drained conditions, strength is defined by effective parameters – effective cohesion and internal friction angle – whereas under undrained conditions, it is governed by the undrained shear strength. Conclusions: Modern finite element complexes that use coupled analysis allow for uniform modeling of soil behavior by varying only boundary conditions and loading rates, making them a powerful tool in geotechnical engineering practice. The use of coupled deformation-seepage analysis and constitutive models based on effective stresses enables, within a single computational framework, the accurate prediction of both the manifestation of undrained shear strength under rapid loading and the realization of effective strength parameters – effective cohesion and internal friction angle – under slow loading |
| Keywords. | finite element method, drained conditions, undrained conditions, soil strength, constitutive model, effective stresses, pore pressure, triaxial test, Cam clay |
| For citations: | Sharaf H.M. Drained and undrained soil loading conditions within the finite element method // News of KSUAE, 2025, № 4 (74), p. 30-39, DOI: 10.48612/NewsKSUAE/74.3, EDN: BERGUW |
