Energy dissipation devices are widely used to enhance the response of structures subjected to dynamic loads caused by wind and earthquake. Especially, viscous dampers are hydraulic devices widely used in structural engineering that dissipate mechanical energy by producing a damping force against the motion. The dampers can mitigate transversal and longitudinal or vertical displacement. It can be set up in different kinds of structures. This study is aimed at comparing the impact of various Fluid viscous damper parameters on the structures under the earthquake. To this aim, a seven-story steel frame structure retrofitted with fluid viscous dampers was considered for analyzing with a variety of parameters. The results showed that installing longitudinal nonlinear Fluid viscous damper can reduce the seismic response significantly, by selecting affordable damping parameters including stiffness, damping coefficient, and velocity exponent. The optimum damping parameters can be calculated accurately by analyzing structure with different damping parameters of nonlinear Fluid viscous damper.

Slope instability in mountainous regions poses serious challenges to infrastructure resilience, particularly under anthropogenic pressures and climatic variability. This study evaluates the mechanical reinforcement provided by Vetiver (Chrysopogon zizanioides) to stabilize slopes in seven representative soils of the Quillollaco Formation, southern Ecuador. Direct shear tests on soil–root composites were used to quantify root-induced improvements in cohesion (c′) and internal friction angle (ϕ′), and slope stability was analyzed with the Spencer limit equilibrium method for heights of 5, 10, and 15 m under dry conditions. Results demonstrated significant reinforcement effects, with Vetiver increasing shear strength parameters at all depths and maintaining safety factors above 1.10 in every scenario. The highest gains, up to 16%, were observed in high-plasticity soils (CH and MH). Sensitivity and inferential statistical analyses confirmed the robustness of these improvements, with over 95% of paired t-tests yielding p < 0.05. These findings highlight Vetiver as a reliable nature-based solution for slope stabilization in tropical mountain environments, offering a sustainable and transferable alternative to conventional geotechnical methods.