The type and the properties of the soil can potentially intensify the internal forces on buildings during seismic loads. To predict the effects of the soil parameters on the soil–structure interaction of buildings, it is necessary to consider the soil–structure interaction (SSI) in the modeling process. Therefore, this document aims to evaluate the seismic effect on the maximal displacement and inter-story drift, and evaluate the behavior of buildings under the second-order effect known in the literature as the P-delta effect. For this purpose, three cases of buildings with 5, 10 and 15 stories were modelled using a FLAC 2D finite-difference element calculation software with infinite soil conditions, including five types of base with four types of soil (one cohesive soil and three non-cohesive soils) considering the soil–structure interaction and a fixed base (without soil–structure interaction). According to the results for the above-mentioned boundary, as the height of the building increases and due to the weak properties of the soil, we notice that the maximal displacements and inter-story drift increase considerably. To that purpose, we recommend considering the second-order effect in seismic design, especially for non-cohesive soil.

The last seismic events showed that tunnel lining may suffer extensive damage. Employing numerical modeling has a great importance in predicting the seismic performance of tunnels. This paper tests the tunnel lining of the Zaouit Ait Mellal (ZAM) twin tunnels located between the cities of Marrakesh and Agadir in Morocco. Dynamic analysis was adopted by FLAC 2D software using the finite-difference elements. Four soil cross-sections were chosen, with different support devices installed along the twin tunnels, such as rock bolts and steel ribs. The seismic signals introduced as input were obtained from three different earthquakes: Al Hoceima 2004 in Morocco, EL Centro 1940 in the USA, and Kobe 1995 in Japan. The numerical results show that the deformation of the tunnel lining is more noteworthy in the sections using steel ribs compared to those using rock bolts, which is observed by the large values of relative displacement, reaching 1020 (mm) and 2.29 × 105 (N.m/m) of maximum bending moment. The analysis indicates that these sections present higher vulnerability during an earthquake, which should be considered when looking at the overall safety of the tunnel.

This study is concerned to the investigation of the stability of bridges by taking into account the soil structure interaction and their impact on the dynamic behavior of the structures. The bridge studied is localized at PK 318 + 750 at the national level, between the city of Al Hoceima and Kasseta (Morocco). The analyses are carried out with the ANSYS code demonstrated that for conditions of support, the distribution of displacements and the fundamental frequency for each type of soil change according to its mechanical properties. This work also indicates that the proximity of the fundamental frequencies of the soil structure and strongly influences the soil-structure interaction.

The precise characterization of mechanical properties is essential to ensure the durability and safety of civil engineering infrastructures, particularly pavements. However, indirect tensile tests (IT-CY) on cylindrical specimens are sensitive to uncertainties related to non-uniform load distributions at the specimen–platen interface, which strongly influence the stress fields and the measurement of the stiffness modulus. This study employs finite element modeling (FEM) using the Abaqus software under the assumption of linear elastic behavior to analyze the impact of three load distribution profiles—uniform, sinusoidal, and parabolic—on the radial, tangential, and shear stress components in cylindrical specimens subjected to diametral compression, with a fixed contact angle of 15°. The simulations reveal significant variations: the uniform distribution generates high stress concentrations (up to 40 MPa in radial stress near the contact zones) and pronounced heterogeneity, thereby influencing the determination of the material’s stiffness modulus. In contrast, the sinusoidal and parabolic profiles promote a smoother stress transition, reducing peak stresses by up to 60% and concentrating the stresses along the vertical diameter. A comparative analysis with experimental results from previous studies supports these observations. Overall, the findings emphasize the critical role of contact conditions in minimizing experimental artifacts and reducing uncertainty in stiffness modulus evaluation. While based on a linear elastic framework, the results provide general mechanical insights that may contribute to the optimization of indirect tensile test protocols and the improvement of pavement design methodologies.