This paper deals with the contribution of the soil-structure interaction (SSI) effects to the seismic analysis of cultural heritage buildings. This issue is addressed by considering, as a case study, the Mosque-Cathedral of Cordoba (Spain). This study is focussed on the Abd al-Rahman I sector, which is the most ancient part, that dates from the 8th century. The building is a UNESCO World Heritage Site and it is located in a moderate seismic hazard zone. It is built on soft alluvial strata, which amplifies the SSI. Since invasive tests are not allowed in heritage buildings, in this work a non-destructive test campaign has been performed for the characterisation of the structure and the soil. Ambient vibration tests have been used to calibrate a refined 3D macro-mechanical-based finite element model. The soil parameters have been obtained through an in situ geotechnical campaign, that has included geophysical tests. The SSI has been accounted for by following the direct method. Nonlinear static and dynamic time-history analyses have been carried out to assess the seismic behaviour. The results showed that the performance of the building, if the SSI is accounted for, is reduced by up to 20 % and 13 % in the direction of the arcades and in the perpendicular direction, respectively. Also, if the SSI is taken into account, the damage increased. This study showed that considering the SSI is important to properly assess the seismic behaviour of masonry buildings on soft strata. Finally, it should be highlighted that special attention should be paid to the SSI, which is normally omitted in this type of studies, to obtain a reliable dynamic identification of the built heritage.

Considering the occurrence of an earthquake, the bearing capacity of a strip footing placed on a saturated cohesive-frictional soil mass has been computed by performing a pseudo-static rigorous analysis incorporating the existence of (i) excess pore water pressures, and (ii) additional seismic-tractions and body forces. The analysis has been carried out by using lower and upper bounds finite elements limit analysis (FELA) in conjunction with the second order cone programming (SOCP) using the Mohr-Coulomb (MC) yield criterion. The generation of the excess pore water pressure in the event of an earthquake has been incorporated by defining a pore pressure coefficient ru-a ratio of the excess pore water pressure to the total vertical overburden stress at any point. The analysis has revealed that the bearing capacity reduces considerably with an increase in the magnitude of horizontal earthquake acceleration. For a given magnitude of earthquake acceleration, the bearing capacity reduces extensively further with an increase in the value of ru. All the computational results have been presented in a non-dimensional manner, and for the validation purpose, necessary comparisons have also been made. The study will be useful for designing foundations in a seismically active zone.

In Turkey sinkhole formations have been observed in recent years, the number of which has increased over time. These sinkholes have started to cause damage to infrastructure and superstructures, especially in rural areas. In this study, considering the rapidly increasing number of sinkholes, first of all, the sinkhole formation mechanism of the region and the characteristics of the sinkhole were examined. Then, an analysis was made on the superstructure inventory of the region. According to the investigations, a numerical study was carried out considering the general characteristics of the sinkholes and the building stock. With this study, three different heights of buildings representing the building stock of the rural area were selected and thus the pressure (S) exerted by the buildings on the ground became a main parameter. In addition to these, a total of 81 finite element models with three different sinkhole widths (D) and four different sinkhole depths (L) selected at four different distances (A) from these structures were created with the finite element program. The structure and sinkhole interaction parameters obtained from the quite comprehensive data set were evaluated in the context of settlements that may occur in the structure. While creating the model, the geotechnical properties of the soil of the region were taken within the scope of the sinkhole formation mechanism. As a result of the analyses, it was observed that the depth of the sinkhole (L), the diameter of the sinkhole (D) and the distance between the sinkhole and structure (A) had a direct effect on the sinkhole-structure interaction, and the structure load had a limited effect. The results also have indicated that the sinkholestructure interaction is limited in the sinkholes formed in diameter and high distance.

The metropolitan region of Belo Horizonte city is home to several high-risk areas with a significant number of mass movement occurrences. Additionally, there are cases of movements in areas that are not considered high-risk, where constructions exhibit a medium to high construction standard. This emphasizes that, in addition to disordered occupations, the terrains have a natural susceptibility to the process. Intervention in slopes through cuts and fills is an unquestionable necessity in geotechnical projects to reinforce unstable or damaged areas. This article explores the field of soil nailing and presents the necessary design practices for its utilization, including safety checks based on deterministic, probabilistic, and finite element analysis. The case study is based in Belo Horizonte, more specifically in the 'Buritis' neighborhood, Brazil. The reinforced slope has a height of 18.5 meters and covers a total area of 1425 square meters. Based on different methodologies, the solution was validated as the most technically feasible, executable, and financially viable.

Natural disasters called landslides have the potential to seriously harm people's safety, the environment, and structures, in addition to causing considerable damage to infrastructure. It is therefore important to be able to model and predict these phenomena. This paper focus on modeling non-linear processes using a finite element model behavior and assess the stability of a slope by calculating the safety coefficient. The characterization work was carried out on a landslide at the site located in Tizi-Ouzou (Algeria). It is characterized by steepness greater than 20%. Verification of the stability of this area, while taking into account the morphology and local geological context of the site, was carried out by finite element modeling using the Mohr-Coulomb criterion and adopting the Cam-Clay model in a Castem step-by-step non-linear calculation code, making it possible to extract the stress field, displacements and deformations and also to find the sliding surface corresponding to a minimum FOS safety coefficient. The results obtained highlight the areas of the slope undergoing plastic deformation, indicative of a high state of stress. The results make it possible to identify the weak points that show that the studied profile is exposed to a risk of landslide, in particular a deep landslide affecting soil layers with a safety factor FOS <1. Preventive actions are recommended to secure the site where supporting measures could be considered.

The current study presents superposition-based concurrent multiscale approaches for porodynamics, capable of capturing related physical phenomena, such as soil liquefaction and dynamic hydraulic fracture branching, across different spatial length scales. Two scenarios are considered: superposition of finite element discretizations with varying mesh densities, and superposition of peridynamics (PD) and finite element method (FEM) to handle discontinuities like strain localization and cracks. The approach decomposes the acceleration and the rate of change in pore water pressure into subdomain solutions approximated by different models, allowing high-fidelity models to be used locally in regions of interest, such as crack tips or shear bands, without neglecting the far-field influence represented by low-fidelity models. The coupled stiffness, mass, compressibility, permeability, and damping matrices were derived based on the superposition-based current multiscale framework. The proposed FEM-FEM porodynamic coupling approach was validated against analytical or numerical solutions for one- and two-dimensional dynamic consolidation problems. The PD-FEM porodynamic coupling model was applied to scenarios like soil liquefaction-induced shear strain accumulation near a low-permeability interlayer in a layered deposit and dynamic hydraulic fracturing branching. It has been shown that the coupled porodynamic model offers modeling flexibility and efficiency by taking advantage of FEM in modeling complex domains and the PD ability to resolve discontinuities.

The seismic safety of heritage buildings may be affected by the interaction between the soil, the foundation and the structure, which is usually neglected in conventional seismic assessments. These factors are particularly important in the case of slender constructions, such as masonry towers, over soft strata. Hence, this work deals with the influence of the soil -foundation -structure interaction in the seismic behaviour of complex heritage masonry towers. The investigations have been carried out considering the case study of the Giralda tower in Seville, Spain. The region is an earthquake -prone area, characterised by far away very large earthquakes with long -return periods. The Giralda tower is a slender brick unreinforced masonry tower, 95 m high and about 13 m wide. It features a high artistic value and popularity as it has been the historical symbol of the city. It was declared a UNESCO Word Heritage Site of Outstanding Universal Value in 1987. Apart from its slenderness, the tower presents some other seismic vulnerabilities: openings irregularities, material heterogeneity and the position of a belfry on the top. Furthermore, the building is placed on soft alluvial strata and has a shallow foundation. Likewise, the tower has a considerable weight, which has caused large settlements. A thorough evaluation of the soil, the foundation and the structure has been carried out to develop a complex and detailed finite element model. Macro mechanical elements and the direct method have been used to develop the numerical model of the tower in the OpenSees framework. Free ambient vibration tests and non-destructive experiments have been used to calibrate the model. Its dynamic behaviour has been evaluated considering the seismic action suggested by the Spanish Code and those determined through a seismic response analysis, bearing in mind different return periods and considering real ground motions. Finally, the numerical results showed that the effect of the soil and the foundation have a significant impact on the seismic behaviour of the bell tower, amplifying the acceleration and its damage at the top.

The accuracy of a constitutive model for confined concrete largely relies on its capability to capture concrete's dilatancy behavior. In this paper, a non -orthogonal flow rule (NFR) is used to reasonably characterize the concrete's volume change law in relation to the stress state without the necessity for a plastic potential function. Then, the non -orthogonal plastic model is implemented in the finite element (FE) software ABAQUS using the implicit stress update algorithm, which employs the line search method and the numerical consistent tangent stiffness matrix to ensure the robustness and computational efficiency of FE analysis. Finally, FE simulations are performed to evaluate the constitutive model's capabilities in actively and passively confined concrete. In the latter case, steel tubes restrict the concrete's lateral deformation. An analysis and discussion are conducted regarding the impact of dilatancy behavior on concrete -filled steel tube (CFST) columns. The consistency between experimental data and simulation results demonstrates that the FE modeling with a non -orthogonal constitutive model provides an effective tool to describe the behavior of confined concrete.

Kathmandu, located in a high seismic zone, predominantly features irregular structures among its building stock. These structures are particularly susceptible to severe damage during seismic events, primarily due to torsional effects. Traditional seismic designs rely particularly on fixed -base conditions that underestimate forces and displacement primarily on soft soil conditions leading to irrational design practices. This study aims to quantify the seismic performance of buildings on various base conditions through fully nonlinear Soil -structure Interaction (SSI). The soil nonlinear behaviour was modelled using the Pressure-Independ-Multi-Yield (PIMY) material with an octahedral shear stress -strain backbone curve. Three distinct soil types were considered, and structures with irregular plan configurations were modelled using finite elements in both Opensees and STKO platforms. Structural performance was analyzed through nonlinear dynamic analysis, and outputs were evaluated based on seismic parameters. Comparing nonlinear SSI with linear SSI and fixed -base conditions revealed a significant increase in structural response, expressed in terms of displacement, drift ratio, and base shear. The magnitude of diaphragm rotation was found to be influenced by a combination of building torsional irregularity and SSI effects. It is suggested that the conventional practice of using the torsional irregularity ratio as a measure of torsional irregularity be revised and enhanced to better account for these influences. It has been quantified that torsional irregularity has a relatively lesser impact on displacements, drifts, and base shear compared to SSI. In all cases, fixed -base conditions consistently exhibited the minimum response. The study explored that linear SSI and fixed -base conditions tend to underestimate structural responses, while nonlinear SSI coupled with dynamic analysis provides a more accurate representation of realistic structural behaviour for seismic design particularly in soft soil cases.

One of the fundamental unknowns in geotechnical engineering, particularly in the design and analysis of retaining walls, is creep. Traditional design approaches for anchored walls often specify a certain prestressing force in the anchors while allowing minimal wall displacement. Unfortunately, the long-term effects of creep are frequently overlooked. Over time, creep leads to increasing displacement in anchored walls, changing the loads acting on stabilizing elements and diminishing the factor of safety for excavation stability. While past research has predominantly focused on short-term behaviour in anchored and nailed walls, only limited attention has been devoted to their long-term behaviour. This study addresses the existing gap by collecting data related to the long-term behaviour of anchored walls in an excavation project. Utilizing two-dimensional finite element numerical modelling, using plane-strain analyses, the study predicts the behaviour of these walls both at the end of the excavation and five years after its completion. Long-term behaviour modelling employs a history matching approach to determine creep variables. Subsequently, the study investigates horizontal wall displacements and changes in loads within the anchors over a five-year period. Through a comparison of modelling results with field measurements, the study demonstrates the model validation in forecasting horizontal displacements at various locations and changes in loads on the anchors over time. Furthermore, the proposed method for long-term deformation calculations of excavation walls enables the anticipation of when horizontal wall displacements may surpass allowable limits. This research concludes with an examination of the evolving trends in anchor loads over time, substantiated by a combination of measurements and numerical modelling.