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The shell structures are commonly used in many civil and industrial and long-span logistic applications. In this research we simply start by applying a degenerated finite element continuum approach. Then we propose a new alternative formulation by splitting the shear energy into two main components, the first one exactly integrated, whereas the second reduced integrated in a proper way. In this numerical and analytical research we present this advanced new approach (herein named penalty partial reduced selective integration) by adding weight coefficients to the splitting energy terms. As a consequence of this formulation, the unwanted locking events are definitively eliminated. A wide range of real and analytical examples, from scientific literature and practical engineering shell design situations, are analyzed and deeply investigated to better understand the level of accuracy and effectiveness of the formulation proposed. Furthermore, comparisons withwell defined and established shell finite elements are made just to yield insight into the predictive capability of the penalty partial reduced selective integration, herein proposed and studied. Hence many examples are used to test this new formulation in order to analyze the numerical behavior of the approximate solution in dependence of the splitting parameters. A simple kind of methodological rules for choosing these numerical non-dimensional parameters are also given.

The current investigation delved into the seismic analysis, design intricacies, and assessment of the response of elevated steel containment tanks when supported by concentrically braced frames. The primary focus was placed on comprehending the behavior of the supporting structure, recognizing its heightened vulnerability to damage under horizontal excitation—insights gleaned from reconnaissance teams studying earthquake aftermaths worldwide. A specific case study unfolded featuring a steel concentrically braced frame as the supporting structure, aligning with prevalent industry norms. Throughout the entire process, spanning design phases, seismic vulnerability assessments, and response evaluations, special emphasis was placed on the internal fluid sloshing phenomena. This nuanced consideration plays a pivotal role in shaping the dynamic response of the system. The study introduces two distinct design methods: the first method aligns with relevant international codes, while the second method innovatively incorporates the compressive strength of the braces into its approach. To evaluate the dynamic response of the elevated tank, both linear and nonlinear advanced analyses were employed. The comparative analysis of various strategies underscores the impact of the chosen design methodology on the overall system response. This multifaceted exploration aims to contribute valuable insights to the seismic resilience and design optimization of elevated steel containment tanks, furthering the understanding of their performance under seismic forces. [ABSTRACT FROM AUTHOR]

Following recent earthquakes, precast buildings exhibited a strong seismic vulnerability related to the presence of closure external panels. The aim of this work is to simulate the seismic response of existing single-storey precast buildings in the case of explicit modelling of external panels. The considered case studies are precast buildings representative of the Italian building stock in the 1970s and 1990s, characterised by two different cladding systems, namely, masonry infills and reinforced concrete precast panels, respectively. The explicit modelling of infills and panels, typically introduced solely as participating masses, provided insights into their actual contribution on the global structural behavior. [ABSTRACT FROM AUTHOR]

This paper presents a general seismic classification procedure for acceleration‐sensitive non‐structural elements (NSEs) based on seismic qualification shake table testing and provides an application example for electrical cabinets in Italy. The proposed seismic classification procedure requires the definition of a set of required response spectra (RRS) for qualification shake table testing defined at different seismic hazard levels and the definition of a formal procedure to generate a test input motion. Each required response spectrum at a given seismic hazard level is then linked to different class levels and the requirements that an NSE should present to achieve each class level are defined. Using this framework, a seismic classification procedure for NSEs is developed for Italy, in which, the RRS are defined according to a peak floor spectral acceleration seismic hazard map of the territory so as to predefine regions in which an NSE belonging to a given class can be installed or not according to either a life safety performance objective or a continuous operation performance objective. Also, the limitations of the proposed seismic classification procedure are outlined. Finally, a nominal application example is presented in which four electrical cabinet specimens were tested on a shake table and their class levels were defined. The results of the application example are used to nominally show how the proposed classification procedure could be applied to discriminate between different types of the same NSE depending on the specific desired application. [ABSTRACT FROM AUTHOR]

The assessment of seismic risk for critical and strategic structures like schools and hospitals remains crucial, even in regions with low seismic activity. Presently, operational school buildings in Sri Lanka are primarily designed to handle gravitational loads without considering capacity-based design principles. Consequently, these structures may lack the necessary lateral resistance to mitigate potential damage or collapse during future earthquakes in Sri Lanka. Hence, conducting seismic risk assessments for such school buildings is imperative to ensure the safety of their occupants. In this research paper, we utilize a recently developed probabilistic seismic hazard map for Sri Lanka to evaluate seismic risk. We employ two nonlinear 3-D finite element models of school buildings created in OpenSees. Incremental Dynamic Analysis is conducted using a well-established set of ground motions, continuing until the structure approaches the point of collapse, to determine the probability of collapse prevention. Subsequently, we develop fragility functions for two limit states, immediate occupancy, and collapse prevention. These fragility curves are then used to compute the probability of exceeding these limit states, aiding in the assessment of the structural safety of the school buildings. A key outcome of this analysis reveals a general trend of increased damage probabilities as the number of stories in the buildings increases despite the distinct structural characteristics of each building. It is also important to note that the disparities between the immediate occupancy and more severe damage cases, such as collapse prevention, are notably pronounced in both two- and three-story school buildings. [ABSTRACT FROM AUTHOR]

Monitoring of non-structural elements is not usually implemented, despite the seismic vulnerability of these components and the significant cost associated with their replacement in case of damage. By exploiting the limited cost of commercial sensors, accelerometers were installed in an existing building to compare accelerations applied to non-structural elements in case of an earthquake with critical acceleration thresholds. The exceedance of these thresholds would indicate a possible danger for the occupants and the need for a more detailed inspection of the element, guiding prioritisation strategies in the aftermath of the earthquake. Furthermore, the real-time probabilistic assessment of potential damage to non-structural elements can serve to identify escape routes and facilitate rescue operations. Critical acceleration thresholds were defined from probabilistic considerations on the expected seismic performance of each typology of non-structural element, described by appropriately selected fragility curves. The feasibility of the proposed procedure was tested by comparing the identified acceleration thresholds with the design values of floor acceleration provided by the Italian Building Code. As a further application, critical acceleration values of the different non-structural elements were compared with a set of real floor acceleration values recorded at the top level of reinforced concrete buildings, highlighting critical non-structural element typologies. [ABSTRACT FROM AUTHOR]

Building Information Modelling is receiving increasing attention as an emerging technology for enhancing the life‐cycle performance of facilities. The cooperation between all professionals involved in the construction chain allows to reproduce digital twins of the structures including information related to different disciplines, such as structural and architectural aspects. In this context, the use of Building Information Modelling, combined with an automatic tool to predict risk indices, could be particularly useful when dealing with existing bridges due to the significant structural deficiencies recently demonstrated by numerous bridge collapses worldwide. This paper explores the development of a BIM‐based procedure to bring greater value in the design, construction, maintenance, and inspection stages. The procedure is applied to existing bridges and it allows to estimate a structural risk prioritization class of bridges according to maintained activities, periodical inspections, structural detailing and modelling uncertainties. The automatic BIM‐based tool uses a workflow developed in Dynamo, and is able to automatically update the structural risk class and to provide warning if the structural safety index exceed defined thresholds. [ABSTRACT FROM AUTHOR]

Old precast buildings are often characterized by poor detailing that may hamper the structural performance, particularly in the case of earthquakes. This is essentially related to: (i) a limited past knowledge of seismic design and behaviour, also reflected in past building codes; (ii) the evolution of seismic zonation of the Italian territory. The aim of this work is to assess the probabilistic seismic vulnerability with respect to the usability preventing damage and global collapse performance levels of four existing single-story precast buildings designed in accordance with past Italian building codes from 1960s to 1990s in three sites with increasing seismic hazard. [ABSTRACT FROM AUTHOR]