The stone roof of the tholos of Athena Pronaia in Delphi: structural hypotheses starting from fragments of marble tiles

This contribution is the first step of a multi-disciplinary research project, aimed at studying the roof of the tholos of Athena Pronaia in Delphi, dating back to the first decades of the 4th century BC. The starting point of this research is the fascination exerted by the tectonic quality of the temple, comprising some complex fragments of marble tiles belonging to the roof of the tholos. Despite the number of studies on this sanctuary, the poor state of preservation and lack of original material did not allow archaeologists to perform concluding research on its original configuration, in particular with reference to the reconstruction of the roof. Aware of the complexity of this topic, this contribution aims at exploring two possibilities, namely, on the one hand, that the fragments of tiles constitute elements supported by a wooden structure, and on the other hand, that they are structural elements of a stone system subjected to compressive stresses. Our contribution intends to serve as food for thought on the need for archaeological studies to be accompanied not only by advanced surveys in the field, aimed at the precise definition of the geometry of the finds, but also by architectural and structural investigations which make it possible to verify the feasibility of the hypothetical reconstructions of the architectural elements aware of the construction techniques used in the past

Historic roof structures: life-cycle assessment and selective maintenance strategies

Many industrial and military constructions built between the end of the IXX century and the first years of the XX century show long span roof structures constructed using slender steel truss members. This characteristic makes the structures almost invisible and the interior space appears larger than it is. After 100 years or more, structures like these are still in good conditions although they may have fallen into disuse and neglect. Usually these buildings are protected by Cultural Heritage regulations. Therefore, it would be interesting to define suitable intervention strategies to maintain, conserve and possibly reuse them. This paper compares three dif-ferent steel roof trusses, covering some buildings of a military installation in Pavia (Northern Italy), built from the end of the IXX century. The residual capacity has been probabilistically evaluated in order to check the efficiency of the most vulnerable members of the structures and investigate systems’ robustness in case of sudden failure of the critical components. The method proposed can be considered as a reliable approach to recognise which structural element is most like to fail, and schedule proper selective maintenance interven-tions

Probabilistic life-cycle assessment and rehabilitation strategies for deteriorating structures: a case study

When it comes to existing buildings, the estimation of the structural residual bearing capacity is required to evaluate the potential for reuse/conversion. The level of detail and accuracy of surveys dramatically affect structural diagnostics. In order to optimise the experimental survey process, a simulation of the structural life-cycle may be useful. Based on a previously developed approach of Monte Carlo simulation implemented with a damage law for the life-cycle analysis of newly designed constructions, this paper presents the method application to a historic roof steel structure. It aims to identify critical situations, assess the residual life of the system, and plan possible retrofit strategies for the building conversion. The case study is a steel frame roof structure of the ex pig abattoir within the complex of the municipal slaughterhouse in Monza (close to Milan, Northern Italy) and protected from the Cultural Heritage Authority. The life-cycle of the structure is here investigated over different stages of the building lifespan along with the damages caused by aging and negligence. The construction was built in 1902, and abandoned in 1984. Therefore, the periods analysed are: from construction to disuse and from disuse to today. The second phase of life, still on going, has significantly sped up the degradation. The probabilistic evaluation of failure times is discussed and the possible interventions scenarios in terms of costs, and after-maintenance reliability and safety are investigated

The role of structures in architecture: the multidisciplinary experience of active learning in a master of science

Purpose: This paper aims to present the integrated teaching activity carried out in the Studios of the Master of Science “Architecture-Building Architecture” held at the School of Architecture Urban Planning Construction Engineering of the “Politecnico di Milano,” Milan, Italy. The integrated teaching activity related to the structural disciplines was in Sgambi et al., 2019; here the structure of the MSc training and its disciplinary synergies will be presented. Indeed, this type of activity characterizes all the Studios of this Master of Science and involves all the disciplines that contribute to the development of an architectural and cultural heritage preservation project. Design/methodology/approach: In the Studios of the aforementioned Master of Science, teachers of different subjects are involved, working together to guide the student in the development of an architectural project sustainable in all aspects. The fundamentals of each discipline are taught using the best suited teaching methodology and the application phase of each discipline is carried out directly on the students' projects in the form of “learning by making.” The students are thus stimulated to deepen their basic knowledge of each single discipline, making their design choices sustainable. Findings: This experience, born in 2003 and still active, has also achieved good results in employment. Students train using the “learning by making” method to acquire proficiencies in various disciplines of design, giving them the ability to communicate competently with experts belonging to different construction sectors. Originality/value: The approach illustrated in this paper does not represent the didactic experimentation of a single discipline, but it is typical of the study program of an entire Master of Science. Although this approach is entirely built on a “learning by making” and “active learning” philosophy, it maintains the teaching of the theoretical contents of disciplines at a significantly high level when compared with the contents of a frontal-taught theoretical course. The development of this structure required a strong commitment on the part of the teaching staff in their search for effective teaching methods in each individual discipline and aimed at the architectural project. The results obtained give an added value to the training of future architects

Fuzzy-random approach to debris model for riverbed scour depth investigation at bridge piers

The removal of sediment around bridge abutments and piers due to the erosive action of flowing water (i.e. scouring) is of the greatest concern to society. Currently it has been estimated that scour produced by rivers and streams causes about 60% of the total amount of bridge failures. Underestimating this natural process can seriously threaten the overall safety of the infrastructure. Several factors may affect the scour depth at bridge piers: flow intensity and sediment grading, flow depth, nature and occurrence of floods, side wall effects, sediment size, geometry and inclination of piers, etc. The depth of the scour hole in the sand adjacent to the bridge foundations can be estimated using theoretical models with hydraulic parameters. However, the uncer-tainty associated with the parameters involved in the evaluation (e.g. flow characteristics, debris, structural and geotechnical factors, etc.) makes it almost impossible to adopt a deterministic approach for the reliability analysis. Therefore, in order to properly assess the structural safety, both aleatory variability (i.e. due to ran-domness) and epistemic uncertainty (i.e. due to limited data and knowledge) must be considered. A fuzzy-probabilistic approach can take some of those uncertainties into account. This paper proposes an original method for modelling the debris action in river bridges. Based on fuzzy-random theory, both the alea-tory variability related to the particle accumulation size and the epistemic uncertainty characterising fluvial hydraulics equations can be successfully modelled

Artificial Intelligence: Hystorical Development and Applications in Civil Engineering Field

Since its first development, the Artificial intelligence has found great applicability to the field of engineering. In particular, the so-called soft-computing methods, are have been shown very effective in the analysis and solution of mal conditioning problems. This paper examines the historical development of this discipline, with particular reference to the long span bridges analisys

Artificial intelligence for the analysis and design of complex bridge structures

A structure can be defined complex if its behavior is influenced from nonlinearities, uncertainties and/or interactions. These aspects increase the complexity of the numerical model that one has to consider to reproduce the actual behavior of the structure. Therefore, many analyses must be developed to investigate particular aspects of the structural behavior of these kinds of structures and the time of analysis may be very expensive. The artificial intelligence theory provide a series of techniques (evolutive procedures, fuzzy theory, neural networks…) that can be used conveniently in order to improve the robustness of the analyses

Fuzzy approach in the three-dimensional non linear analysis of reinforced concrete two-blade slender bridge piers

A modern conceptual design of a bridge structure should be open to wider criteria, which assure that the structure is endowed with static, dynamic and ductile characteristics sufficient to tackle the seismic events. For the satisfaction of these requirements and for the exploration and the verification of innovative structural schemes, one must consider refined and subtle analysis formulations and tools. Such a kind of structural scheme is based on the two-blade slender bridge piers. These are elements subdivided into two parts with different geometric and mechanical properties. The first part has a box section, highly stiff; two flexible blades connected to the top compose the second part. Due to the uncertainties involved in the problem, the geometrical and mechanical properties that define the structural problem cannot be considered as deterministic quantities. In this work such uncertainties are modeled by using a fuzzy criterion

Analisi tridimensionale delle tensioni generate dalla precompressione nei solai alveolari

In this work the spalling cracks of the precast slab floor has been analysed by a three-dimensional finite element analysis. A parametric study and a comparison by a normative rules are also presented

Structural time-dependent damage analysis relying on efficient simulation models and deterioration laws.

Structural time-dependent damage analysis relays on efficient simulation models and deterioration laws. When a probabilistic experiential methodology is applied to existing constructions, the simulation is going to describe the damage state already achieved as well as the further damage evolution. In order to process a reliable damage law, it is necessary to define the deterioration condition in the present and predict it in the future. The parameter law characterisation needs to be identified according to experiential data. This paper presents the parameter characterisation process in a damage law according to non-invasive experiential data collection. The case here discussed is applied to the timber rooftop of a rural structure. Since the structural system is assembled in different periods, which means the life span is multifarious, and the damage degree is different, the calibration procedure reliability and the law versatility can be proved