Geotechnical seismic isolation (GSI) has emerged as a potential technique to mitigate the effects of earthquakes, with many applications to structural configurations, such as bridges and buildings. ...It consists of absorbing the seismic energy from the soil to the superstructure by interposing a superficial soil layer in order to reduce the accelerations that filter from the soil to the structure. This mitigation technique is particularly suitable in developing countries since GSIs are low-cost seismic isolation systems that through relatively simple manufacturing processes allow to safe costs and stimulate many applications. The presented study aimed to perform 3D numerical finite element models that overcome the previous contributions by performing several structural configurations. Several historical earthquakes are considered in this paper, and the results may be applied to drive general assessments of the technique in case of future seismic hazards.
The assessment of bridge functionality during earthquakes is fundamental in the evaluation of emergency response and socio-economic recovery procedures. In this regard, resilience may be considered a ...key parameter for decision-making procedures such as post-hazard event mitigations and recovery investments on bridges. The paper proposes a case study of a bridge configuration subjected to seismic hazard and aims to consider the effects of the soil–structure interaction on the recovery to various levels of pre-earthquake functionality. The principal outcome of the paper consists of calculating resilience as a readable finding that may have many applications for a wide range of stakeholders, such as bridge owners, transportation authorities and public administrators who can apply the outcomes in the assessment of the best recovery techniques and solutions.
Resilience has become an interesting parameter to assess the seismic risk connected with functionality of structures. In this regard, losses due to earthquakes may be significantly reduced by ...applying isolation at the base of the structures. However, design of isolation needs to consider the effects of soil deformability and all the connected effects of Soil Structure Interaction (SSI). In particular, soil deformability may reduce significantly the benefit of base isolation and thus the computation of resilience needs to consider such conditions. This paper aims to consider the issue by considering several isolated configurations on different soil conditions and for each of them, the seismic resilience has been computed. Numerical simulations have been performed in order to calculate the resilience of the various configurations and then this parameter was chosen a reference for comparing the isolation models on different soil conditions.
Pile foundations is a well-studied technique with many applications and its benefits on structures have been widely studied in the literature. In particular, the mutual effects of pile flexibility ...and soil deformability may significantly modify the seismic behaviour of superstructures. In order to consider the uncertainties that are connected with these issues, the paper applies the probabilistic-based approach of fragility curves by proposing three limit states based on ductility factor. Non-linear dynamic analyses were performed with OpenSees PL to assess the potentialities of three pile configurations founded on three cohesionless soil with different deformability.
Geotechnical seismic isolation (GSI) consists of an innovative technique to mitigate the effects of earthquakes based on interposing a superficial soil layer to filter the seismic energy from the ...soil to the structure. This approach is particularly applied in developing countries due to low-cost applications. In order to account the uncertainties, the presented paper aimed to develop fragility curves of 3D configurations performed by numerical finite element models. The mail goal is to assess and discuss the potentialities of GSI as a mitigation technique for several configurations. Opensees PL has been applied to perform the numerical analyses and to realistically reproduce the behaviour of GSI.
The seismic vulnerability of structures is closely related to changes in the degree of soil saturation that may cause significant changes in volume and shear strength, and consequently, bearing ...capacity. This paper aims to consider this issue during the strong earthquake that struck Southern Italy on 23 November 1980 (Ms = 6.9) and affected the Campania and Basilicata regions. Several 3D numerical finite element models were performed in order to consider the effects of soil–structure interaction (SSI) on a representative benchmark structure. In particular, the role of the water level depth is herein considered as one of the most significant parameters to control the shear deformations inside the soil, and thus the performance of the superstructure. Results show the importance of considering the water level for buildings on shallow foundations in terms of settlements, base shear forces and floor displacements.
Soil structure interaction (SSI) effects have been extensively studied with advanced numerical simulations even if these approaches are time consuming and require much effort to perform. In ...particular, when SSI models are compared with fixed based ones, two main effects need to be considered: period elongation and damping increase. The paper proposes numerical models to build fixed based models calibrated on these two parameters and perform complex SSI analyses. A new framework that may be used to assess SSI with equivalent fixed-based models is herein presented and validated with non-linear dynamic numerical simulations. Opensees was performed to reproduce non-linear numerical simulations by considering hysteretic materials and advanced soil models.
Modern and smart cities are significantly vulnerable to natural hazard, and their functionality is based on resilient infrastructure systems. In particular, seismic resilience may be considered the ...ability to deliver services during and after hazard events. Therefore, it is fundamental to identify the most critical components within a system, especially when multiple infrastructure systems are interdependent. The paper aims to propose a novel methodology that consider interconnected infrastructures to assess seismic resilience that may be defined as a function that depends on time, and the different components are considered the functional dimensions. The proposed methodology may be applied for several typologies of infrastructures, specifically looking at the seismic resilience analyses related to transportation systems. A case study has been considered in order to apply the proposed formulation and to demonstrate the importance of considering interdependency in the assessment of the seismic resilience. Many stakeholders (infrastructure owners, public administrations, decision makers) may be interested in applying the methodology that could be used to study several applications.
The concept of seismic resilience has been introduced in the design of buildings in the last decade. In this regard, the delay time may be defined as the time that occurs between the event and the ...moment the repair process begins. In the literature, only a few contributions have considered delay time, and even its definition is still under discussion. However, it is a key parameter in the assessment of resilience after earthquakes since it may significantly increase the total time after which a structure may be considered recovered. The principle at the base of the paper is that seismic structural health monitoring (S2HM) may play a significant role in reducing the delay time. Therefore, delay time needs to be considered since it may significantly reduce the seismic resilience of structural systems. The paper aims to consider this important issue demonstrating the relationship between S2HM and the assessment of the seismic resilience of buildings. In particular, the assumption herein is that the accuracy of the S2HM may be described with different levels, and in correspondence with these levels, certain values of the delay time may be considered. In addition, the delay time is considered as a percentage of the total repair time. A multidimensional definition that includes the accuracy of S2HM in the description of the delay time is herein proposed to be included in methodologies that aim to assess seismic resilience.
The assessment of resilience of health infrastructures during an epidemic crisis is a fundamental issue in civil engineering, as shown by the recent COVID-19 crisis. During epidemic crises, health ...services and infrastructures need to maintain a level of functionality and avoid failures. In addition, it is important to evaluate post-hazard procedures, such as emergency and recovery actions. In this regard, the paper applied resilience as a parameter to assess investments, countermeasures and mitigations. The Resilience-Based (RB) methodology herein proposed was then applied to quantify the resilience of health infrastructure systems by considering the recovery of four European Countries (Germany, France, United Kingdom and Italy) after the first wave of COVID-19. The results demonstrated that the resilience of health system infrastructures (HSI) depends significantly on the policies that every government management applied—these being ultimately responsible for the differences in respective COVID impacts. In particular, the principal advantage of using resilience lies in its readability by many stakeholders, such as health infrastructure managers, government owners and public authorities.
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