Horizontal Actions Research Articles

Perspectives of integrated climate change and water policies in Hungary

The paper aims to outline the climate impacts induced and transferred by water and the socio-economic factors that exacerbate them. It also seeks to provide a common and integrated policy framework for climate change adaptation and water management. The climatic and non-climate drivers, the risk chains and options for policy integration are assessed in four complex thematic areas: (i) ecosystem services, (ii) food supply chain: agriculture, food processing industry, food safety; (iii) industrial and service activities, energy and water supply, infrastructure, built environment, and (iv) human health and well-being, social justice. In these complex thematic areas, we examine the risk cascade chain, the current state of impacts and expected future challenges within a coherent framework and then make concrete proposals for possible specific areas of policy integration. Finally, in the conclusions, we present municipal-level good practices in water-resilient climate adaptation and formulate the horizontal actions needed to implement integrated climate-water policy.

A Novel Strategy for the Equivalent Frame Modelling of Masonry Arches in Historic Buildings: Application to a Case Study

ABSTRACT Equivalent frame (EF) methods are increasingly used to evaluate the global seismic response of historic masonry buildings. However, applying these methods to arched structures is challenging due to the lack of a standard EF strategy for masonry arches. This paper proposes a novel EF modelling solution for masonry arches in historic buildings subject to seismic actions. The proposed strategy, which consists in modelling arches as inclined hinged beams, is presented through the application to a case study, the Giuseppe Verdi Politeama Theatre in Carrara, Italy. Nonlinear static analyses were first performed on a finite element (FE) macro-model of a representative arch-pillar system found in the building. The numerical results in terms of damage mechanisms and capacity curves allowed the development of an EF modelling strategy for masonry arches. This strategy was then applied to a three-dimensional EF model of the Politeama Theatre to evaluate its global seismic response through nonlinear static analyses. The results demonstrated the effectiveness of the proposed strategy in accurately simulating the contribution of the arches in resisting horizontal actions.

Safety assessment of masonry undamaged and damaged arches subjected to gravitational loads and horizontal forces. A numeric procedure to identify the optimal thrust line

In 2019 the authors formulated a numerical procedure for assessing the safety of masonry arches based on their geometry and the shape of the thrust line. The thrust line is calculated to be nearest to the geometric axis of the arch, because it is that corresponding to the optimal inner stress state. The original procedure, which focused on the safety analysis of undamaged fixed arches subject to gravitational loads, is reformulated here to also consider arches on pinned supports as well as damaged arches, i.e. one- and two-hinged arches. The procedure is further extended to also assess safety against horizontal actions, such as those resulting from an earthquake. Finally, safety is evaluated by identifying the domain of admissible thrust lines within the thickness of the arch and by computing the degree of safety in terms of the capacity of the thrust line to be moved vertically within the domain. The reformulation and extension of the procedure exploits the technique of partitioned matrices to enable automation and easy implementation in structural calculation software.

Wavelet technique and FEA for modal identification in damaged URM shear walls

In existing masonry buildings, the structural capacity with respect to horizontal actions is due to the in-plane response of shear walls, usually evaluated in terms of effective stiffness and drift capacity. The objective of this work is to provide first results to the damage sensitivity in diagonal cracking of URM shear walls and a study methodology based on vibration tests to assess the structural health of existing masonry buildings. The state of pre-existing discontinuities caused by previous damage events or material degradation may play a role in the in-plane response of shear walls. For this, an experimental campaign was carried out on three typologies of UnReinforced Masonry (URM) walls, simulating different damage situations, subjected to Shear-Compression (SC) and vibration tests in order to correlate the structural behaviour with changes in modal parameters. From the vibrational response acquired during the SC test, the modal parameters related to the pre-damage and post-damage condition were identified using the Continuous Wavelet Transform identification technique. The experimental results are then used to implement a Finite Element Model (FEM) with a 2D homogenization approach to simulate the behaviour of URM walls. A parametric study through FEM analysis is carried out in order to investigate the change in modal parameters for different damage configurations and for triggering strut mechanisms.

Experimental and Numerical Analysis of Concrete Columns under Axial Load Based on European Design Norms

This study presents a comparison between numerical and experimental results for reinforced concrete columns subjected to axial compression. Depending on the columns support and their organization within the structure, columns primarily work under either concentric or eccentric compression, respectively, bending in situations where horizontal actions such as wind or/and earthquakes are present in the structure. Different countries have specific design codes, and in this study, the calculation of columns is based on the European design codes, specifically EN 1992-1-1. As a common practice in most cases during research, tests are conducted using computational models, and based on the obtained results through the application of similarity theory, an attempt is made to transition to the actual behavior of structural elements. Therefore, this paper applies a logic of "almost real" testing, where two columns with square cross-sections were produced and tested. The columns had a rectangular base with cross-section dimensions of 20/20 cm and a height (L) of 300 cm, with a concrete strength of fcm,cube=61.80 MPa. They were reinforced with longitudinal reinforcement (4Ø12 mm) and had a tensile strength of ftm=588.10 MPa. Additionally, stirrups of Ø8 mm were placed at every sw=25 cm. Experimental results show a closer alignment with software calculations using SEISMOSOFT with an accuracy of 96%, while results according to EN 1992-1-1, based on simplified methods, show 64% for the Nominal Stiffness Method and 59% for the Curvature Method. Doi: 10.28991/CEJ-2024-010-02-05 Full Text: PDF

Dynamic-Based Limit Analysis for Seismic Assessment of Free-Standing Walls of San Giovanni Church in Castelseprio UNESCO World Heritage Site

Free-standing archaeological walls are significantly exposed to horizontal actions (e.g., earthquakes) as they lack connections provided by floors or roofs. In such cases, the dynamic response governs the activation of local mechanisms of collapse, determining the shape of the macroblocks and their position. Engineering models of archaeological walls are developed according to the results of extensive visual inspections and on-site testing, including modal identification for calibration purposes. A modal response spectrum analysis on the calibrated model identifies the zones where the tensile stress is exceeded, which are more likely to detach as rigid macroblocks and subsequently overturn due to the expected ground spectra. The macroblocks are then assessed according to limit analysis. The case studies are the north and the apse walls of the church of San Giovanni Evangelista in Castelseprio (Varese, Lombardy), a 5th century Longobard fortified settlement, a part of UNESCO World Heritage. The construction quality of the apse was poorer than the north wall, but the masonry of both is very compact thanks to the good mortar. The macroblocks are identified mostly in the upper crests of the walls, and their acceleration of activation is two to six times larger than the demand (considering the dynamic amplification that the structure applies to the ground motion); therefore, no particular intervention is needed. The proposed method will require additional calibration, e.g., through nonlinear dynamic analyses, and a more precise treatment of uncertainties in masonry mechanical properties to determine the shape of the macroblocks.

The Church of San Giovanni Evangelista in Castelseprio – multi-disciplinary strategies for the characterization of the masonry structures

The remains of the archaeological site of Castelseprio (Varese province, Italy) are listed under the UNESCO World Heritage as proof of one of the seven settlements of the Lombards in Italy. Freestanding elements belonging to the apse and the lateral walls of the church of San Giovanni Evangelista are still preserved nowadays, reaching heights around 5 and 10 m, respectively. The condition of these walls, both in terms of slenderness and incompleteness, constitutes a possible vulnerability under horizontal actions that would need to be assessed for conservation. In particular, the presence of multi-leaf and/or low-compact sections could limit the structural capacity of the walls and contribute to brittle collapses, even under low forces. According to the analyses of mortars carried out in the excavation site, the specific characteristics of the local geo-resources (clay-rich sediments traditionally called “Ferretto” deposits) directly influenced the incidence of pozzolanic binding processes, allowing the formation of two different aluminosilicate-based reaction products based on a standard calcic system (C-A-S-H) and on a magnesian one (M-A-S-H). This peculiar reuse of local lateritic soils, with a high concentration in the bedding mortars of the foundational structures, increased not only the general durability of the masonry but also the mechanical properties of the first architectural complex of San Giovanni. Based on the types of mortar identified, various configurations of wall sections were assumed (monolithic and multi-layered) and their mechanical behaviour through kinematic analyses was compared, to evaluate the relevant limits of the seismic capacity of the walls.

Diaphragm effect of unreinforced historical masonry vaults

In historical masonry structures, and particularly in churches, vaults have a fundamental role in bearing the vertical loads of floors and roofs. However, in past earthquakes they have proved vulnerable, representing a source of fragility under horizontal loading. In addition, the global seismic behavior of masonry structures is strongly affected by the stiffness of flooring elements (diaphragm effect), which, when sufficient, allows for transfer of horizontal actions to stiffer wall working in-plane.In this paper, the diaphragm effect of historical masonry vaults under horizontal loads is investigated numerically. A parametric nonlinear Finite Element model of a cross vault is subjected to in-plane shear actions on two supports to evaluate the response and damage during an earthquake. This work is preparatory for future physical testing activities on scaled prototypes to be performed within a broader research project, aimed at the enhancement and exploitation of artistic and cultural heritage.

A simplified micro-model based on discrete elements and elastic bodies for non-linear static analysis of in-plane loaded masonry panels

In this paper, a simplified micro-model based on a combination of continuum (2D) and discrete elements was developed to estimate non-linear behavior and failure prediction of masonry panels subjected to in-plane loads. Bricks were substituted by 2D elastic elements which connected via eight bi-component non-linear springs to each other. Each spring has axial and shear behavior which is represented by mortar axial stress–strain curve, including softening and brick–mortar cohesion-friction law, respectively. Substantial simplifications are accomplished due to employing elastic panels and concentration non-linearity at the discrete elements in terms of the possibility of implementation in commercial software. The validation process was conducted at two levels; first: a masonry cell under possible in-plane loading conditions and second: ten experimental panels having different geometrical and mechanical properties subjected to vertical and horizontal actions simultaneously. The obtained results including global behavior and crack pattern were compared with experimental ones as well as available numerical predictions from the literature. High accuracy was observed despite convergence ease and reduction in both pre-processing and analysis time.

Biaxial capacity envelopes for the capacity design of biaxially loaded shallow foundations

Earthquakes cause bi-directional horizontal actions on structures. While Eurocode 8 recognizes this fact and mandates that the horizontal components of the design seismic action shall be taken as acting simultaneously, neither Eurocode 8 nor the existing literature provide the interaction behaviour of biaxially loaded shallow foundations. Further, it is to be noted that, in a real structure, the horizontal force and moment acting on a foundation, are inter-related through the effective height of the supported column. The present study considers the inter-relation between horizontal force and moment to generate the normalised vertical load-biaxial horizontal load (V-Hx-Hy) capacity envelopes, which can also be used to directly obtain the V-H-M and V-Mx-My capacity envelopes, considering the effective height of the structure. To develop the V-Hx-Hy capacity envelopes, three-dimensional (3D) finite element limit analyses are performed on surface as well as embedded square and rectangular footings, resting on dry sand. The main factors affecting the capacity of a biaxially loaded shallow foundation are discussed. The effect of ground acceleration on the capacity envelope is highlighted. Limitations of the current design procedures for the design of biaxially loaded foundations are demonstrated, through a case study. Finally, a procedure for the capacity design of biaxially loaded shallow foundations, using capacity envelopes, is proposed.

Design procedure for failure mode control of linked column frames

This paper investigates the seismic behaviour linked column frames (LCFs). This structural system, traditionally, consists of moment frames for the gravity loads and dual columns interconnected with bolted links for the horizontal actions. An optimized design approach is herein developed for the LCFs according to the Theory of Plastic Mechanism Control (TPMC) through a closed form solution assuring the maximum energy dissipation, i.e., the development of a collapse mechanism of global type. Several structural schemes are designed according to the proposed design approach considering different geometry, link length and structural height. The accuracy of the TPMC is evaluated through nonlinear static and dynamic analyses. In particular, the dynamic analyses are developed for a selection of designed fames to highlight the difference in terms of performances among the structures with short, long and intermediate links.

Empirical fragility curves for masonry churches and their macro-elements using a large database: Proposal of a new likelihood function

Several earthquakes have highlighted over time the high vulnerability of masonry churches to horizontal actions, so that more and more research is being devoted to the assessment of their seismic response and to the design of strengthening interventions to guarantee their preservation.This paper analyses in detail the damage suffered by a large sample of 2870 masonry churches hit by the 2016–17 Central Italy seismic sequence, using the damage data extracted from the DaDO Web GIS. Fragility curves based on the empirical/observational approach are elaborated starting from the damage probability matrices (DPMs) in terms of global damage, both for the whole database and for some subsets of churches with homogeneous characteristics, in order to analyze the influence of some typological features. In particular, it is highlighted that the subset of small churches with rectangular plan and single nave show a generally lower vulnerability compared with those of the whole database.Moreover, the damage observed in the most common macro-elements detectable in masonry churches is examined by defining specific damage indices for macro-elements. The fragility curves for the macro-elements are, then, compared with those referring to the global damage, evidencing some interesting aspects useful both in the survey phase and for planning specific interventions. One of the main outcomes is that the seismic responses of the ‘Façade’ and ‘Principal nave’ macro-elements may closely approximate the global response of the church.Finally, the paper presents a new fitting procedure of the observational damage data aimed to build fragility curves for subsets of churches characterized by a reduced number of data falling in some PGA ranges. A ‘weighting’ procedure is, indeed, proposed in order to give less relevance to small groups of churches falling in the less populated PGA ranges.

The effect of the gravity column in the seismic design of steel CBFs

In this work, the effect of the gravity column in the seismic design of X-braced CBFs is analysed through a simplified design procedure. The analysis is performed by dividing the structural typology as a sum of two substructures: the Gravity Column (GC) substructure, with the primary aim of bearing vertical actions; and the Bracing substructure, mainly reacting to the horizontal actions. The analysis of the influence of the GC in the seismic design has been deepened by exploiting the Controlled Collapse Design Theory for CBFs. By imposing the collapse configuration, the storey displacement vector is obtained and, through the deformability matrix for the GC substructure, the horizontal actions acting on this substructure are defined. An analysis of the effects of seismic design is carried out considering the percentage of total shear force due to the GC substructure, for two case studies. In addition, a cost-(seismic) benefit analysis between the Controlled Collapse Design Theory and EC8 Design, is carried out.

Pre- and Post-Diction Simulation of the Seismic Response of a Masonry Cross Vault Tested on a Shaking Table

ABSTRACT Masonry vaults are widely employed in ancient constructions and play a crucial role in their static and dynamic behaviour. In the last decades, the scientific community has carried out, on the one hand, several experimental campaigns aimed at characterising the response of masonry vaults to horizontal actions; on the other, it has developed sophisticated numerical models able to capture the crucial features of their structural response. Within the framework of the SERA.TA project (Seismology and Earthquake Engineering Research Infrastructure Alliance for Europe), pre- and post-diction contests have been organised to assess the capability of numerical methods to predict the seismic response of a 1:1 scale model of a masonry cross vault, realised and tested at LNEC laboratory (Portugal). This paper outlines the numerical analyses performed on two vault models within the pre- and post-diction phases of the project. The numerical models have been created and analysed with NOSA-ITACA, a finite element software developed by ISTI−CNR and devoted to the structural analysis of ancient masonry constructions. Pros and cons of the numerical simulations have been analysed, comparing the prediction and post-diction results with the experimental data in terms of accelerations, displacements, and crack patterns. Numerical results fit the experimental outcomes, and betterment is evident in the post-diction phase.

О работе сборных водопропускных труб в теле насыпи двухпутного земляного полотна

Purpose: To find out features of operation of precast reinforced concrete culverts in the embedding soil bulk of the two-track embankment with account of interaction of precast culvert structures and soil for the case of oppositely directed towards the first and second tracks combination of horizontal components of train loads at opposite transit of trains in the ulvert area; to propose on selection of methods of reinforcement of culvert structures with account of conditions of their operation in the two-track subgrade. Methods: The analysis and use of analytical and expemental research methods for evaluating operation of culverts in the body of the subgrade including two-track setions of railway. Analytical comparison of research results and data of instrumental observations. Results: There have beendentified the features of interaction of the body of the precast culvert with the body of the two-track embankment at oppositely directed horizontal components of the train load, there has been analyzed the nature of distribution of stress-strain state of the embedding soil bulk of the two-track subgrade along the culvert body. There has been demostrated a negative influence of the combination of oppositely directed towards the first and second tracks combination of horizontal components of train loads at opposite transit of trains on the body of the precast culvert in the embankment of two-track sections. Practical significance: The obtained results concerning the stress-strain behavior of the embedding soil bulk and distribution of forces along the culvert body at combination of oppositely directed horizontal actions at the two-track subgrade allowed identifying the nature of their joint operation and, based on it, proposing on selection of methods of reinforcement of culvert structures with account of conditions of their operation in the subgrade of two-track parts of railways.

The formation of sensory life discourse in the conditions of “Other” sociocultural experience

The article discusses the study of discourse related to sensual life within the context of a different sociocultural experience. The formation of this discourse is said to be influenced by legitimizing the horizontal principle in social relations, which is mainly constituted by research and developmental epistemic and discur-sive influences on the social, political, and cultural situation in society. The author employs a methodological procedure to differentiate between sensory perception and sensory understanding at the level of emotional intellect, highlighting the indi-vidual contributions of each in shaping the discourse on sensual life. It is conclud-ed що the request for the constitution of the existential meanings of the organization of life is growing under the influence of the growth of the degree of individual freedom of human beings and the formation of an open communicative space of life. They are formed in the field of voluntary horizontal actions, prompting the person to self-activation and sense finding. Sense is associated with human sensation, sensitivity and perception “at the level of the senses” and physicality "at the level of intelligence”. Meaning at the “sense level” is manifested by “common sense” and the right direction in life, and “at the intellectual level,” meaning is determined by reflective thinking, relevant discursive ethical practices and worldviews as well as cognitive orientations.

Limit analysis and design-oriented approach for out-of-plane loaded masonry walls strengthened by grouted anchors

Masonry structures without box-like behaviour are often prone to the complete or partial out-of-plane failure of their walls under horizontal actions, i.e. mainly the seismic ones. Steel grouted anchors or tie-rods have been widely used in the past to improve connections between orthogonal walls and avoid out-of-plane mechanisms. However, reliable analytical approaches to design such strengthening systems are lacking, whereas the evaluation of their effectiveness is still a matter of ongoing research. The paper presents a force-based design approach to assess the performance of three-wall masonry systems strengthened by grouted anchors, using a frictional macro-block model and a non-standard limit analysis, previously developed for unreinforced masonry structures. The extension of this model to strengthened masonry systems, with specific reference to the use of grouted anchors, allows assessing their horizontal capacity in terms of minimum load multiplier and expected failure. The novel aspects introduced in the updated model are: (1) a simplified closed-form formulation for the calculation of the stabilising moments provided by the grouted anchors at the onset of the failure mechanism, (2) the possibility of placing the grouted anchors with variable inclinations, which may improve their stabilising contribution and optimise the intervention. The effectiveness of the simplified formulation is firstly proved by the comparison with literature results; then, several parametric analyses are carried out to highlight the influence of some variables on the capacity of both the unreinforced and the strengthened three-wall system. Finally, a literature example related to a traditional intervention with steel tie-rods is used to apply the proposed procedure and investigate the performance of different design solutions with innovative grouted anchors.

Calibration of concrete damaged plasticity materials parameters for tuff masonry types of the Campania area

The masonry buildings represent the largest portion of the Italian building heritage considering that about eighty percent of buildings is made of different kind of masonry. Italian cities are characterized by the presence of numerous masonry buildings of historical and architectural value. It is possible to find a large variety of building techniques and constructional material leading to different masonry structures that need to be precisely characterized as regards the mechanical behaviour. In this paper, the calibration of the materials parameter for an adequate modelling of typical tuff masonry constructive systems spread in Campania region is given. The calibration has been developed reproducing, by FEM analysis, real compression tests performed in displacement control available in literature. In particular, reference is made to masonry with regular ashlars, listed tuff masonry and chaotic tuff masonry. The FEM analyses have been carried out considering the “Concrete Damaged Plasticity” failure criteria. Moreover, the modelling of a wall subjected to horizontal actions has been investigated with reference to solid brick elements and shell to analyse if there is any shape factor affecting the different response. It can be pointed out that the analytical model used for the calibration of uniaxial tension and compression curves shows great adaptability and versatility for each type of masonry.

Infuence of inverted-v-braced system on the stability and strength of multi-story steel frames

Population growth in urban centers, together with the lack of physical space, has led to the construction of increasingly tall and slender buildings. Multiple-story structures present substantial challenges to civil engineering because they have specific requirements for their design, construction, and use. The increased number of foors leads to more lateral displacements resulting from horizontal actions. Under these conditions, to ensure system stability, structural bracing components are commonly adopted. In addition, along with the use of more resistant materials and new construction techniques, it is necessary to improve the methodologies adopted in the structural analysis to offer professionals in the area the conditions to undertake safer and more economical projects with better speed and efficiency. Thus, in this study, numerical analyses were applied to steel planar reticulated structures to evaluate their stability and strength when inserting bracing systems. The study compared the arrangement of the bars and analyzed the influence of the parameters of the bracing systems, such as the properties of the cross-section and the position of the inverted-V-braced system. The MASTAN2 program was used to perform nonlinear static assessments using reticulated finite elements that considered both geometrical and physical nonlinearities. It was observed that the inverted-V-braced system had a substantial impact on all of the structures that were analyzed, providing increased stiffiness and, as a result, significantly reducing the frame’s lateral displacement.

Fibre reinforced mortars for the out-of-plane strengthening of masonry walls

Unreinforced masonry buildings (URM) often suffer of local out-of-plane failure mechanisms of the walls during a seismic excitation. This study investigates the effectiveness of a relatively novel class of inorganic composite materials, namely Fibre Reinforced Mortars (FRM), for the out-of-plane strengthening of masonry walls. Three experimental tests by using a novel setup to perform out-of-plane tests on masonry panels, part of an enlarged ongoing testing campaign, are presented herein. The specimens are solid clay brick masonry walls subjected to compressive axial load and out-of-plane horizontal actions according to a “four-point bending test” scheme. Two specimens are reinforced before testing with FRM, one in single-side and another one in double-side configurations, while the third specimen is tested in the bare configuration. Experimental results are reported and discussed. The preliminary results attest that FRMs are effective in increasing the out-of-plane capacity of masonry walls and in postponing the activation of the out-of-plane failure mechanism.