The objective of this paper focuses primarily on the numerical approach based on two-dimensional (2-D) finite element method for analysis of the seismic response of infinite soil-structure interaction (SSI) system. This study is performed by a series of different scenarios that involved comprehensive parametric analyses including the effects of realistic material properties of the underlying soil on the structural response quantities. Viscous artificial boundaries, simulating the process of wave transmission along the truncated interface of the semi-infinite space, are adopted in the non-linear finite element formulation in the time domain along with Newmark's integration. The slenderness ratio of the superstructure and the local soil conditions as well as the characteristics of input excitations are important parameters for the numerical simulation in this research. The mechanical behavior of the underlying soil medium considered in this prediction model is simulated by an undrained elasto-plastic Mohr-Coulomb model under plane-strain conditions. To emphasize the important findings of this type of problems to civil engineers, systematic calculations with different controlling parameters are accomplished to evaluate directly the structural response of the vibrating soil-structure system. When the underlying soil becomes stiffer, the frequency content of the seismic motion has a major role in altering the seismic response. The sudden increase of the dynamic response is more pronounced for resonance case, when the frequency content of the seismic ground motion is close to that of the SSI system. The SSI effects under different seismic inputs are different for all considered soil conditions and structural types.

This study investigates the seismic performance of reinforced concrete (RC) framed buildings with ribbed slab floors in the aftermath of the 06 February 2023 Kahramanmaraş earthquakes. The structural analysis of a 6-story RC building with ribbed slab floors that collapsed during the earthquake was conducted using the finite element analysis and compared with a similar structure built with traditional slab floors. For this purpose, a sample building was selected in the Islahiye district of Gaziantep province, one of the regions most affected by the earthquake. The analysis revealed that the vibration periods of ribbed slab systems were longer than those of conventional slab systems due to their lower in-plane stiffness. Additionally, the study found that ribbed slab orientation significantly amplifies P-delta effects caused by geometric non-linearity, especially in soft-story buildings. A key finding of the study is that the high vertical accelerations recorded during the earthquakes, comparable to horizontal accelerations, generated large inertial forces that were directly transferred to the columns in buildings with ribbed slabs. These forces doubled the second-order effects in the first story compared to traditional beam-slab systems, triggering soft-story collapse mechanisms. The study underscores the high seismic vulnerability of ribbed slab buildings, particularly those without shear walls, and emphasizes the urgent need for stricter seismic design regulations to prevent future catastrophic failures.

This research develops and evaluates a recyclable corrugated cardboard vibration isolation box reinforced with balsa wood as an alternative to traditional open trench methods for mitigating ground-borne environmental body waves. This study includes designing and testing scaled prototypes, laboratory analyses, prototype fabrication, and full-scale field experiments. In soft ground conditions, ensuring slope stability during deep excavations is a key engineering challenge for open trenches. For this purpose, scaled prototypes were subjected to laboratory tests to assess the resistance of the wave barrier’s wall surface. Numerical analyses were also conducted to evaluate the strength of the internal lattice structure under various loads. A prototype was fabricated for on-site experiments simulating real-world conditions. Field experiments evaluated the vibration isolation performance of the proposed barrier. Accelerometer sensors were strategically placed to gather data, analyzing ground surface vibrations for free field motions to assess the vibration shielding efficiency of both the open trench method and the corrugated vibration isolation box, with and without Styrofoam infill. This study concludes that the recyclable corrugated vibration isolation box is a viable alternative, offering comparable or improved vibration isolation efficiency in soft soil conditions while promoting environmental sustainability using recyclable materials.