ABSTRACT This paper presents a probabilistic life-cycle cost analysis of pile-supported wharves under seismic and corrosion hazards influenced by climate change. A multi-hazard framework combines nonlinear time-history analysis with a chloride-induced pitting corrosion model to assess structural deterioration under future climate scenarios. Six scenarios capture uncertainty in climate and corrosion severity. Results show that climate-induced corrosion has a significant impact on seismic fragility and long-term performance, with scenarios involving climate change and severe corrosion increasing cumulative failure costs by 8.6%. The methodology facilitates the optimization of inspection, maintenance, and design strategies for coastal infrastructure.

ABSTRACT This study develops a Geographic Information Systems (GIS)-based framework for regional landslide susceptibility mapping, integrating seismological, hydrological, and remote sensing data with machine learning techniques. Focusing on the Mashair Mina area near Makkah, a region of critical importance due to the annual Hajj pilgrimage, the methodology combines the Mora-Vahrson (M-V) heuristic model with the Iterative Self-Organizing Data Analysis Technique (ISODATA) clustering algorithm to quantitatively assess and classify landslide hazards. The resulting hazard map delineates the region into five risk zones: very high (20.23%), high (11.22%), moderate (31.01%), low (26.41%), and very low (11.12%). The very high-risk zones are strongly associated with steep slopes, unconsolidated materials, and proximity to active faults, whereas the lowest hazard zones correspond to stable geology and gentle topography. Validation against recent landslide occurrences indicates that more than 85% of past events fall within high or very high hazard zones, confirming the predictive reliability of the model. The study concludes that integrating unsupervised machine learning with heuristic methods provides a robust, non-subjective, and scalable approach to landslide hazard assessment. Beyond advancing geospatial modeling, the framework offers a practical tool for land-use planning, infrastructure development, and disaster risk reduction in Mina and other geohazard-prone regions worldwide.

ABSTRACT Soil-structure interaction (SSI) plays a critical role in evaluating seismic performance and guiding damping design in earthquake-prone regions. This study investigates the influence of damping layers placed between the half-space and the foundation on dynamic SSI and the seismic response of the superstructure under plane SH waves. Therefore, an analytical solution is developed by coupling the wavefunction expansion method with the transfer matrix method, and it is verified by reducing the model to a published exact solution when the damping layers become sufficiently small. Parametric analysis reveals that seismic damping layers have a significant effect on the displacement response of both the foundation and superstructure, as well as the surface ground motions. Increasing the shear wave velocities and the number of damping layers, while decreasing the layer thickness, can attenuate the seismic response of the foundation and superstructure. In addition, the surface ground motions exhibit strong sensitivity to the incident angles. The results show that the structural response under earthquake excitation can be effectively mitigated by appropriately designing seismic damping layers. They also provide valuable insights for seismic design and earthquake resilience, extending and advancing previous analytical DSSI studies.

ABSTRACT The surface motion during earthquakes can undergo significant changes owing to the two-dimensional field effect. In addition to the terrain effect, the nonuniformity of the surrounding soil density can significantly affect the dynamic response of a site to earthquakes. In this study, the wave function expansion method and Graf’s addition formula are used to derive an analytical solution for the dynamic response of a cutting site under SH wave incidence with the soil density represented by an arbitrary function. The displacement amplitude results for the cutting site surface under a radial density distribution are subsequently presented. The seismic responses of isosceles-shaped road cuts are investigated under various incident angles, dimensionless frequencies, cutting slope, and density parameters. The results indicate that the nonuniformity of the soil density around road cuts can significantly alter the dynamic responses of local site surfaces under seismic action. One of the most important results is that, compared with the case of soil with a homogeneous density, the nonuniformity of the soil density around the soil cutting does not independently influence the various parameters of the seismic response results. The presence of density parameters exacerbates the seismic interaction between the soil and the structure. In addition, the results of simplifying the model to a flat ground model indicate that the nonlinear effect of the soil causes amplification of shear waves during propagation.

ABSTRACT This study evaluates the seismic performance and fragility characteristics of a reinforced concrete shear wall building that remained undamaged during the 2023 Kahramanmaraş Earthquake in Türkiye. Although designed for Life Safety, the building achieved Immediate Occupancy performance under strong shaking. Nonlinear response history analysis and fragility functions based on material strain and shear capacity were used to assess probabilistic performance limits. Results highlight the effectiveness of code-conforming, symmetrical shear wall systems in ensuring seismic resilience. This case study offers a benchmark for earthquake-resistant design and emphasizes the value of robust structural systems grounded in performance-based engineering principles.

ABSTRACT Based on traditional viscoelastic dampers and incorporating the structural advantages of corrugated steel plates, a novel viscoelastic damping wall (i.e. Corrugated Steel Plate Viscoelastic Damper, CSPVD) was proposed. By considering design parameters such as the corrugation directions (horizontal or vertical), the thickness ratio of the corrugated steel plates, and the thickness ratio of the viscoelastic material, the hysteretic energy dissipation behavior of CSPVD under low-frequency cyclic loading was analyzed using ABAQUS. The results indicate that the vertical layout of corrugated steel plate in CSPVD (VCSPVD) exhibits superior energy dissipation performance compared to the horizontal layout (HCSPVD). Furthermore, with a decrease in the aspect ratio of the corrugated steel plate and the overall height-to-width ratio, as well as an increase in the yield strength of the corrugated steel plate, the energy dissipation performance of CSPVD improves. However, variations in the width-to-thickness ratio and hardness of the viscoelastic material have relatively minor effects on the energy dissipation capacity of CSPVD. Finally, the resilience model of CSPVD provides a valuable reference for analyzing the elastic-plastic seismic response in structural systems equipped with CSPVD.

ABSTRACT This study proposes a region-specific Newmark displacement prediction model for earthquake-induced landslides in New Zealand, leveraging deep transfer learning. Analyzing 681 New Zealand ground-motion records from 20 earthquake events, the model integrates nine variables (earthquake source/site parameters, critical accelerations, and ground-motion intensity measures) and slope aspect effects. The residual analysis, performance evaluation, and comparative validation demonstrate that the proposed model meets the criteria for precise predictions and offers improved accuracy compared to existing models. The framework advances seismic landslide hazard assessment by enabling reliable displacement predictions in areas with insufficient data or those not covered by the earlier models.

ABSTRACT Elevated reinforced concrete (RC) water tanks are a critical component of urban infrastructure. However, past earthquakes have exposed their vulnerability – particularly due to poor material quality and inadequate detailing. Although the benefits of concrete confinement are well recognized in structural engineering, their specific impact on the seismic performance of elevated tanks has not been adequately quantified. This study addresses that gap by evaluating the effect of confinement on the collapse fragility of a typical 100 m3 RC water tank under varying conditions. A comprehensive parametric study was conducted using 48 nonlinear finite element models incorporating two material grades (low-strength C10/S220 and moderate-strength C20/S420), four support conditions (fixed base and soil types C, D, D1), and three reservoir fill levels (empty, half full and full). Each scenario was modelled with and without confinement and subjected to non-linear time-history analysis using 30 ground motions scaled through Multiple Stripe Analysis. This resulted in 7200 simulations. Collapse fragility curves were developed based on three limit states: local (single-hinge), combined (double-hinge), and global (drift-based) collapse criteria. The results demonstrate that confinement significantly improves seismic capacity – raising median collapse accelerations by up to 40–60%, particularly in low-quality, fully filled tanks. The absence of confinement was found to increase collapse risk more than poor soil conditions or low material strength. These findings offer new insights by isolating the role of confinement and its interaction with the foundation/soil and fluid systems in tank fragility – an aspect that was overlooked in previous studies – and underscore the need to include it in seismic vulnerability assessments.

ABSTRACT The use of urban underground space is increasing due to the rapid urbanization of cities worldwide, and piggyback twin tunnels are inevitable in such cases. The present study uses the modified pseudo-dynamic approach to analyze the interaction effect between piggyback twin circular tunnels in a granular medium under vertically propagating shear and primary waves. Emphasis is given to determining support pressure and stress distribution in the finite element lower bound limit analysis framework and second-order cone programming. The support pressure has been evaluated using the Unequal Normal Stress Approach (UNSA). From the distribution of normal stresses obtained using UNSA, the support pressure for each tunnel must be greater than the maximum normal stress exerted by the soil on the tunnel periphery. The normal stress on the top tunnel’s invert and bottom tunnel’s crown was significant for closely spaced tunnels. Due to body wave propagation, the normal stress distribution is skewed toward the predominant direction of the horizontal acceleration. The variation of support pressures of both the tunnels with soil friction angle, cover depth, separation distance, peak base amplitude of seismic acceleration, dimensionless frequency, and time of seismic waves is presented. Tunnels placed at a close center-to-center spacing and a relatively shallow depth are highly vulnerable to seismic body wave propagation. The practical application of the current study has been demonstrated considering the 1995 Kobe earthquake in Japan.