41 results on '"Bruno Dal Lago"'
Search Results
2. Multi-Stripe Seismic Assessment of Precast Industrial Buildings With Cladding Panels
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Krunal Gajera, Bruno Dal Lago, Luca Capacci, and Fabio Biondini
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seismic vulnerability ,precast structures ,industrial buildings ,probabilistic assessment ,panel connection systems ,multi-stripe analysis ,Engineering (General). Civil engineering (General) ,TA1-2040 ,City planning ,HT165.5-169.9 - Abstract
Following the empirical observation of widespread collapses of cladding panel connections of precast industrial buildings under recent seismic events, new design solutions have been developed in the framework of the European project SAFECLADDING, including isostatic systems effectively decoupling the seismic response of frame structure and cladding panels. The present paper is aimed at evaluating the seismic response and vulnerability of precast frame structures employing pendulum, cantilever, and rocking cladding connection systems. Within the framework of the research project RINTC–Implicit seismic risk of code-conforming structures funded by the Italian Civil Protection Department within the ReLUIS program, the seismic performance of a typical precast industrial building has been assessed with a probabilistic approach based on the results of static and multi-stripe dynamic non-linear analyses. The seismic vulnerability assessment of each structural system has been carried out with reference to life safety and damage limit states considering three sites of increasing seismic hazard in Italy. The effect of distributed panel mass modeling vs. more common lumped mass modeling has been analyzed and critically commented based on the results of demand over capacity (D/C) ratios. Moreover, biaxial seismic D/C ratios have been evaluated for realistic strong hinge connections for cladding panels.
- Published
- 2021
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3. Experimental and Numerical Assessment of the Service Behaviour of an Innovative Long-Span Precast Roof Element
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Bruno Dal Lago
- Subjects
precast concrete ,pre-stressing ,roof elements ,non-linear modelling ,visco-elasticity ,full-scale experimentation ,Systems of building construction. Including fireproof construction, concrete construction ,TH1000-1725 - Abstract
Abstract The control of the deformative behaviour of pre-stressed concrete roof elements for a satisfactory service performance is a main issue of their structural design. Slender light-weight wing-shaped roof elements, typical of the European heritage, are particularly sensitive to this problem. The paper presents the results of deformation measurements during storage and of both torsional–flexural and purely flexural load tests carried out on a full-scale 40.5 m long innovative wing-shaped roof element. An element-based simplified integral procedure that de-couples the evolution of the deflection profile with the progressive shortening of the beam is adopted to catch the experimental visco-elastic behaviour of the element and the predictions are compared with normative close-form solutions. A linear 3D fem model is developed to investigate the torsional–flexural behaviour of the member. A mechanical non-linear beam model is used to predict the purely flexural behaviour of the roof member in the pre- and post-cracking phases and to validate the loss prediction of the adopted procedure. Both experimental and numerical results highlight that the adopted analysis method is viable and sound for an accurate simulation of the service behaviour of precast roof elements.
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- 2017
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4. Soft omega joint for selective weakening of core walls in large precast commercial buildings
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Bruno Dal Lago, Marco Del Galdo, and Andrea Nino Consiglio
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Architecture ,Building and Construction ,Safety, Risk, Reliability and Quality ,Civil and Structural Engineering - Published
- 2023
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5. Structural assessment of modular precast 3D cell mid- to high-rise buildings with different connections
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Bruno Dal Lago, Luca Volpe, and Enrico Papa
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Earth-Surface Processes - Published
- 2023
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6. Seismic behavior of precast concrete coupled shear walls with yielding-based and friction-based coupling beams
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Qiang Fang, Jian Sun, Hongxing Qiu, Bruno Dal Lago, and Weihong Chen
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Mechanical Engineering ,Civil and Structural Engineering - Published
- 2023
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7. Slender precast voided slabs under <scp>walking‐induced</scp> vibration
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Bruno Dal Lago, Luca Martinelli, and Francesco Foti
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discomfort ,vibrations ,Mechanics of Materials ,numerical simulation ,smartphone-assisted testing ,design against vibrations ,prestressed slabs ,General Materials Science ,Building and Construction ,precast structures ,Civil and Structural Engineering - Published
- 2022
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8. Tension-only ideal dissipative bracing for the seismic retrofit of precast industrial buildings
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Marco Lamperti Tornaghi, Bruno Dal Lago, and Muhammad Naveed
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Computer science ,0211 other engineering and technologies ,020101 civil engineering ,02 engineering and technology ,Industrial buildings ,0201 civil engineering ,Seismic analysis ,Dissipative devices ,Bracing system ,Framing (construction) ,Precast concrete ,Capacity spectrum ,Precast structures ,Seismic retrofit ,Civil and Structural Engineering ,021110 strategic, defence & security studies ,business.industry ,Building and Construction ,Structural engineering ,Geotechnical Engineering and Engineering Geology ,Brace ,Bracing ,Geophysics ,Buckling ,Design process ,business - Abstract
New precast frame industrial structures are seismically designed according to reliable modern criteria. However, most of the existing built stock hosting many workers and both regular and strategic industrial activities was designed and detailed neglecting the earthquake load or according to outdated seismic design criteria and regulations. Its seismic retrofit is a main challenge for the Engineering Community and a critical objective for institutional and private bodies. Among the envisaged solutions, the introduction of dissipative braces appears to be promising, although mostly inapplicable for these buildings, due to the brace lengths required by their typical large dimensions and the related proportioning against buckling. In this paper, an innovative seismic retrofitting technique based on monolateral dissipative bracing is investigated. The device proposed in this paper, yet in phase of preliminary design and testing, dissipates energy through friction in tension only while freely deforming in compression, which makes the issue related to compressive buckling irrelevant. A numerical analysis is carried out to investigate the efficiency of the proposed device in seismic retrofitting of precast industrial frame buildings with the aim to explore its feasibility and to better orient the definition of the slip threshold load range and the future development of the physical device. The simplified Capacity Spectrum Method (CSM) is employed for the global framing of the structural behaviour of the highly nonlinear retrofitted structures under seismic actions. A numerical tool is set to automatically apply the CSM based on the definition of few main parameters governing the seismic response of precast frame structures. The efficacy of the CSM is critically analysed through the comparison with the results of a set of nonlinear dynamic analyses. A smart simplified design process aimed at framing the most efficient threshold slip/yield load of the device given an existing structural configuration is presented with the application of the CSM through the identification of the most efficient performance indicator related to either displacement, shear force, equivalent dissipation of energy or a combination of them.
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- 2021
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9. Experimental tests on shallow foundations of onshore wind turbine towers
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Bruno Dal Lago, Luca Flessati, Pietro Marveggio, Paolo Martinelli, Giancarlo Fraraccio, Claudio di Prisco, and Marco di Prisco
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granular material ,soil-structure interaction ,experimental testing ,wind turbine towers ,Building and Construction ,reinforced concrete ,fiber-reinforced concrete ,Mechanics of Materials ,shallow foundations ,soil–structure interaction ,General Materials Science ,Civil and Structural Engineering - Published
- 2022
10. Role of numerical modelling choices on the structural response of onshore wind turbine shallow foundations
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Paolo Martinelli, Luca Flessati, Bruno Dal Lago, Giancarlo Fraraccio, Claudio di Prisco, and Marco di Prisco
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Reinforced concrete ,Onshore wind turbine ,Fibre-Reinforced Concrete ,Granular material ,Nonlinear FE analyses ,Shallow foundations ,Soil-structure interaction (SSI) ,Architecture ,Building and Construction ,Safety, Risk, Reliability and Quality ,Civil and Structural Engineering - Published
- 2022
11. Contributors
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R. Bento, Gabriele Bernardini, Ivo Caliò, J.M. Castro, César Chácara, Fernando Ramirez Cortes, R. Couto, You Dong, Andreea Dutu, Rafael Ramírez Eudave, Carina Fonseca Ferreira, Tiago Miguel Ferreira, Euiseok Jeong, Bruno Dal Lago, Daniel Mocanescu, Bartolomeo Pantò, Hugo Rodrigues, Junwon Seo, I. Sousa, Giovanni Sumerente, Nicola Tarque, Jing Qian, and Changhai Zhai
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- 2022
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12. Tests and Design of Welded-bar Angle Connections of Precast Floor Elements
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Bruno Dal Lago, Marco Del Galdo, and Davide Bisi
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General Materials Science ,Building and Construction - Published
- 2022
13. Modelling and Seismic Response Analysis of Non-residential Single-storey Existing Precast Buildings in Italy
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Marco Bosio, Chiara Di Salvatore, Davide Bellotti, Luca Capacci, Andrea Belleri, Valeria Piccolo, Francesco Cavalieri, Bruno Dal Lago, Paolo Riva, Gennaro Magliulo, Roberto Nascimbene, Fabio Biondini, Bosio, Marco, Di Salvatore, Chiara, Bellotti, Davide, Capacci, Luca, Belleri, Andrea, Piccolo, Valeria, Cavalieri, Francesco, Lago, Bruno Dal, Riva, Paolo, Magliulo, Gennaro, Nascimbene, Roberto, and Biondini, Fabio
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connections ,friction ,industrial buildings ,precast ,seismic assessment ,Building and Construction ,Geotechnical Engineering and Engineering Geology ,Settore ICAR/09 - Tecnica delle Costruzioni ,precast, industrial buildings, connections, friction, seismic assessment ,Civil and Structural Engineering - Abstract
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.
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- 2022
14. Correction to: Wind Tower FRC Foundations: Research and Design
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Luca Flessati, Matteo Colombo, Bruno Dal Lago, Giulio Zani, Claudio di Prisco, Marco di Prisco, Paolo Martinelli, and Giancarlo Fraraccio
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Engineering ,business.industry ,Structural engineering ,business ,Tower - Published
- 2021
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15. Wind Tower FRC Foundations: Research and Design
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Marco di Prisco, Paolo Martinelli, Giancarlo Fraraccio, Matteo Colombo, Giulio Zani, Luca Flessati, Claudio di Prisco, and Bruno Dal Lago
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Reinforced concrete ,Engineering ,Fibre reinforced concrete ,Finite element modelling ,Reduced scale prototypes ,Wind tower foundations ,business.industry ,Structural engineering ,business ,Tower - Published
- 2021
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16. Experimental evaluation on the seismic behavior of precast concrete shear walls with slip-friction devices
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Qiang Fang, Jian Sun, Hongxing Qiu, Hongbo Jiang, Bruno Dal Lago, and Fabio Biondini
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Mechanics of Materials ,Architecture ,Building and Construction ,Safety, Risk, Reliability and Quality ,Civil and Structural Engineering - Published
- 2022
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17. Experimental Testing of a Bolted Connection System for Precast Concrete Load-bearing Panel Structures
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Consiglio, ANDREA NINO, Muciaccia, Giovanni, and BRUNO DAL LAGO
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Horizontal joints ,Precast structures ,Precast structures, Mechanical connections, Experimental testing, Vertical joints, Horizontal joints ,Experimental testing ,Mechanical connections ,Vertical joints - Published
- 2021
18. Testing walking-induced vibration of floors using smartphones recordings
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Bruno Dal Lago, Vitomir Racic, Francesco Foti, and Luca Martinelli
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mechatronics ,Accuracy and precision ,Control and Optimization ,accelerometers ,Computer science ,lcsh:Mechanical engineering and machinery ,Modal testing ,020101 civil engineering ,02 engineering and technology ,Pedestrian ,Accelerometer ,0201 civil engineering ,0203 mechanical engineering ,Artificial Intelligence ,lcsh:TJ1-1570 ,ground reaction forces ,Simulation ,Microelectromechanical systems ,Measure (data warehouse) ,human-induced loading ,Mechanical Engineering ,structural vibrations ,Mechatronics ,smart sensors ,MEMS ,Vibration ,020303 mechanical engineering & transports ,ComputerSystemsOrganization_MISCELLANEOUS - Abstract
Smartphone technology is rapidly evolving, adding sensors of growing accuracy and precision. Structural engineers are among customers who indirectly benefit from such technological advances. This paper tests whether accelerometers installed in new generations of smartphones can reach the accuracy of professional accelerometers created for vibration monitoring of civil engineering structures, and how they can be useful. The paper describes an experimental study designed to measure walking-induced vibrations of a slender prefabricated prestressed concrete slab. Both traditional, high-accuracy, accelerometers and those integrated into commercial smartphones were used for experimental data collection. Direct comparison of the recordings yielded two key findings: the accuracy of smartphone accelerometers largely depends on the specific smartphone model, and nevertheless is satisfactory for preliminary modal testing at the very least. Furthermore, the smartphone measured accelerations of the lower back were used successfully to indirectly measure pedestrian walking loads.
- Published
- 2020
19. Seismic actions induced by cladding panels on precast concrete frame structures
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Luca Martinelli, Francesco Foti, and Bruno Dal Lago
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Cladding (construction) ,Materials science ,business.industry ,Precast concrete ,Structural engineering ,business - Abstract
The strong earthquakes occurred in Southern Europe in the last decade pointed out a poor seismic performance of the connection system of the cladding of precast industrial structures. The cladding of these buildings usually consists of sandwich concrete panels of remarkable mass, connected to the frame structure with mechanical devices. The estimation of the out-of-plane seismic action on these connections is a key step for their correct proportioning. However, the formulation currently provided in the Eurocode 8 for the estimation of the seismic action on non-structural elements was calibrated with different objectives. Furthermore, given there is no in-plane structure-panel interaction, a quote of the panel mass is lumped in correspondence of their connection for a correct proportioning of the frame structure. The designers need to make assumptions on both aspects that often bring to remarkably different solutions. The paper presents a consistent dynamic formulation of the problem of the vibration of rigid bodies connected with cantilever columns. The solution brings to closed-form equations to evaluate the exact out-of-plane action on the connections and the correct amount of panel mass to be lumped.
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- 2018
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20. Seismic design and performance of dry-assembled precast structures with adaptable joints
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Alberto Dal Lago, Paolo Negro, and Bruno Dal Lago
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mechanical connections ,Cantilever ,seismic performance ,Computer science ,Structural system ,0211 other engineering and technologies ,Soil Science ,020101 civil engineering ,Precast structures ,joint adaptation ,dry joints ,non-linear analysis ,full scale testing ,02 engineering and technology ,Precast structures, joint adaptation, mechanical connections, dry joints, seismic performance, non-linear analysis, full scale testing ,0201 civil engineering ,Seismic analysis ,Prefabrication ,Precast concrete ,medicine ,Redundancy (engineering) ,Civil and Structural Engineering ,021110 strategic, defence & security studies ,business.industry ,Stiffness ,Structural engineering ,Geotechnical Engineering and Engineering Geology ,Bending moment ,medicine.symptom ,business - Abstract
Previous research projects and post-earthquake field observation showed that dry-assembled precast frame structures with hinged beams and cantilever columns restrained at their base, if correctly designed and detailed, can attain good seismic performance, mainly due to their flexibility and robustness. Their seismic design is often conditioned by the need of reducing their flexibility by increasing the cross-section of the columns, which, due to minimum reinforcement requirements, results in their over-strengthening. High flexibility may also induce displacement compatibility issues with non-structural elements. The paper concerns the proposal of an innovative enhanced structural frame system, based on the adaptation of hinged beam-column joints into rigid through the activation of special mechanical connection devices performed after the installation of the slab. While keeping all the benefits of the dry prefabrication, the resulting moment-resisting frame is provided with enhanced redundancy and stiffness. A design comparison among three precast frames with similar geometries and different static schemes shows how the joint adaptation can be exploited to optimise the structure by modifying the distribution of bending moment. The results of dynamic non-linear analyses on a three-storey precast structure with adaptable joints tested as a part of the SAFECAST research programme show the seismic performance of this system through different static schemes, and the comparison with the experimental results provides information about the validity of the models and the effectiveness of the technological solutions employed.
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- 2018
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21. Conceptual design and full-scale experimentation of cladding panel connection systems of precast buildings
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Giandomenico Toniolo and Bruno Dal Lago
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021110 strategic, defence & security studies ,Engineering ,business.industry ,European research ,0211 other engineering and technologies ,Full scale ,020101 civil engineering ,02 engineering and technology ,Structural engineering ,Geotechnical Engineering and Engineering Geology ,Civil engineering ,0201 civil engineering ,Seismic analysis ,Joint research ,Cladding (construction) ,Conceptual design ,Precast concrete ,Earth and Planetary Sciences (miscellaneous) ,business ,Civil and Structural Engineering - Abstract
Summary Despite the long series of European research projects that has led to the setting of fully reliable seismic design criteria for precast structures, recent earthquakes have shown that a weak point still exists in the proportioning of the connection systems of cladding wall panels. Following this finding, this paper outlines an organic setting of the design problem of precast concrete structures including cladding–structure interaction and describes three possible solutions, namely, the isostatic, integrated, and dissipative systems. The related fastening arrangements, with the use of existing and innovative connection devices, are also described. This paper comments on the results of the pseudo-dynamic and cyclic tests performed at ELSA Laboratory of the European Joint Research Centre of Ispra (Italy) on a full-scale prototype of precast structure. The conception and the experimental performance of the structure with nine different configurations of either vertical or horizontal wall panel claddings are presented. The analysis of the results highlights the effectiveness of the different solutions in a comparative way. Copyright © 2017 John Wiley & Sons, Ltd.
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- 2017
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22. Experimental Investigation on Steel W-Shaped Folded Plate Dissipative Connectors for Horizontal Precast Concrete Cladding Panels
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Giandomenico Toniolo, Fabio Biondini, and Bruno Dal Lago
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Engineering ,0211 other engineering and technologies ,Right angle ,020101 civil engineering ,02 engineering and technology ,0201 civil engineering ,Seismic analysis ,Cladding Panels ,Dissipative Connectors ,Precast Structures ,Seismic Design ,Seismic Retrofit ,Civil and Structural Engineering ,Building and Construction ,Geotechnical Engineering and Engineering Geology ,Cable gland ,Precast concrete ,021110 strategic, defence & security studies ,business.industry ,Structural engineering ,Cladding (fiber optics) ,Nonlinear system ,Dissipative system ,Seismic retrofit ,business - Abstract
A dissipative connector device, consisting of a steel plate folded at right angle along three lines to get a W-shaped profile, is proposed for the safe fastening of the horizontal cladding panels of new or existing precast structures under seismic action. Experimental tests are carried out to characterize the hysteretic behavior of the connector device. Different technological features, restraint conditions, and loading protocols are considered. Nonlinear hysteretic models are validated against the results of pseudo-dynamic tests on a full-scale prototype of precast building with cladding panels. Guidelines for the design of the dissipative connector device are provided.
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- 2017
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23. Diaphragm effectiveness of precast concrete structures with cladding panels under seismic action
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Bruno Dal Lago, Silvia Bianchi, and Fabio Biondini
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Computer science ,0211 other engineering and technologies ,02 engineering and technology ,Seismic analysis ,Deck ,Dissipative devices ,Precast concrete ,Roof ,Diaphragm action ,Mechanical connections ,Non-linear analysis ,Precast structures ,Seismic performance ,Civil and Structural Engineering ,Building and Construction ,Geotechnical Engineering and Engineering Geology ,Geophysics ,Parametric statistics ,021110 strategic, defence & security studies ,business.industry ,Structural engineering ,Stiffening ,Diaphragm (structural system) ,business ,Mechanical devices - Abstract
The seismic performance of precast frame structures strongly depends on the mechanical devices connecting both structural and non-structural elements. Following recent post-earthquake field observations of unintended seismic interaction of the cladding panels with the frame structure, the seismic design of the cladded system is currently being critically examined by the scientific community. Design solutions involving a controlled cladding–structure interaction have been proposed to address this problem. However, the frame–panel interaction may draw high stresses into the roof diaphragm, as a consequence of the stiffening of the external frames only. This paper presents a parametric study based on linear and non-linear dynamic analyses investigating different levels of interaction among frames, panels, and diaphragm system. The results show how the deck and cladding connections influence the seismic behaviour of the structure. Innovative fastening systems aimed at enhancing the seismic performance of the structure are proposed based on the use of dissipative connection devices inserted into both cladding and deck components.
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- 2019
24. EFFECTS OF MODELLING ASSUMPTION ON THE EVALUATION OF THE LOCAL SEISMIC RESPONSE FOR RC PRECAST INDUSTRIAL BUILDINGS
- Author
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Michele Egidio Bressanelli, Andrea Belleri, Gennaro Magliulo, Paolo Riva, Davide Bellotti, and Bruno Dal Lago
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Engineering ,business.industry ,Precast concrete ,Structural engineering ,business - Published
- 2019
- Full Text
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25. Correction to: Tension-only ideal dissipative bracing for the seismic retrofit of precast industrial buildings
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Muhammad Naveed, Marco Lamperti Tornaghi, and Bruno Dal Lago
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Engineering ,Hydrogeology ,Ideal (set theory) ,business.industry ,Tension (physics) ,Building and Construction ,Structural engineering ,Geotechnical Engineering and Engineering Geology ,Bracing ,Geophysics ,Precast concrete ,Dissipative system ,Seismic retrofit ,business ,Civil and Structural Engineering - Published
- 2021
- Full Text
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26. Experimental investigation on the influence of silicone sealant on the seismic behaviour of precast façades
- Author
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Giandomenico Toniolo, Fabio Biondini, Bruno Dal Lago, and Marco Lamperti Tornaghi
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Engineering ,Structural system ,Silicone sealant ,0211 other engineering and technologies ,Cladding panels ,Precast structures ,Seismic design ,Civil and Structural Engineering ,Building and Construction ,Geotechnical Engineering and Engineering Geology ,Geophysics ,020101 civil engineering ,02 engineering and technology ,STRIPS ,0201 civil engineering ,law.invention ,Seismic analysis ,chemistry.chemical_compound ,Silicone ,law ,Precast concrete ,European commission ,021110 strategic, defence & security studies ,business.industry ,Structural engineering ,Joint research ,chemistry ,business - Abstract
Silicone sealant is usually interposed between panels of precast facades. In ordinary cladding panel configurations, relative sliding between panels occurs under lateral actions. The shear drifts and consequent stresses arising in the silicone strips may lead to a significant increase of the load demand in the cladding panel connections and affect the seismic behaviour of the structural system. This paper presents the results of experimental tests and numerical analyses carried out to clarify the role of the silicone sealant on the seismic response of precast structures with cladding panels. An experimental campaign including monotonic and cyclic tests on both silicone strips applied to small concrete blocks and two panel sub-assembly sealed with silicone, has been developed at Politecnico di Milano. Furthermore, cyclic and seismic pseudo-dynamic tests on a full-scale prototype of precast building with cladding panels sealed with silicone, have been performed at the Joint Research Centre of the European Commission. The results of the experimental tests are presented and compared with the results of numerical simulations. Some recommendations for seismic design of precast frame structures with cladding panels, considering the effect of silicone sealant, are finally provided.
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- 2016
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27. Influence of different mechanical column-foundation connection devices on the seismic behaviour of precast structures
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Marco Lamperti Tornaghi, Bruno Dal Lago, and Giandomenico Toniolo
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021110 strategic, defence & security studies ,Engineering ,business.industry ,Precast concrete structures · Seismic performance · Mechanical connections · Column-to-foundation joint · Numerical analysis ,0211 other engineering and technologies ,Full scale ,020101 civil engineering ,02 engineering and technology ,Building and Construction ,Structural engineering ,Dowel ,Dissipation ,Geotechnical Engineering and Engineering Geology ,0201 civil engineering ,Geophysics ,Precast concrete ,Seismic risk ,business ,Ductility ,Joint (geology) ,Beam (structure) ,Civil and Structural Engineering - Abstract
Dry-assembled precast concrete frame structures are typically made with dowel beam-to-column connections, which allow relative rotation along the beam direction. In the orthogonal direction the rotation of the beam is prevented but again the connections of the superimposed floor elements allow for relative rotation. All the ductility and energy dissipation demand in case of seismic action is therefore concentrated at the base of cantilever columns. Hence, the column-to-foundation connection plays a key role on the seismic performance of such structures. Mechanical connection devices, even if correctly designed for what concerns resistance, may affect the behaviour of the whole joint modifying the ductility capacity of the columns and their energy dissipation properties. An experimental campaign on different mechanical connection devices has been performed at Politecnico di Milano within the Safecast project (European programme FP7-SME-2007-2, Grant agreement No. 218417, 2009). The results of cyclic tests on full scale structural sub-assembly specimens are presented. Design rules are suggested for each of the tested connections on the basis of the experimental observations, and numerical analyses have been performed with hysteretic parameters calibrated on the experimental loops. The seismic performance of structures provided with those connections is investigated through a case study on a multi-storey precast building prototype, which has also been subject to full-scale pseudo-dynamic testing within the same research project at the European Laboratory of Structural Assessment of the Joint Research Centre of the European Commission. The comparison of the results from the structure provided with the different studied connections clearly highlights how some solutions may lead to both reduction of ductility capacity and dissipation of energy, increasing the expected structural damage and the seismic risk.
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- 2016
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28. Seismic performance of precast concrete structures with energy dissipating cladding panel connection systems
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Giandomenico Toniolo, Bruno Dal Lago, and Fabio Biondini
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021110 strategic, defence & security studies ,Cladding panels ,business.industry ,0211 other engineering and technologies ,Precast structures ,Experimental testing ,020101 civil engineering ,02 engineering and technology ,Structural engineering ,Building and Construction ,Strength of materials ,Dissipative connections ,Seismic design ,Civil and Structural Engineering ,Materials Science (all) ,Mechanics of Materials ,0201 civil engineering ,Seismic analysis ,Cladding (construction) ,Precast concrete ,General Materials Science ,business ,Geology - Published
- 2018
29. Sliding channel cladding connections for precast structures subjected to earthquake action
- Author
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Bruno Dal Lago and Marco Lamperti Tornaghi
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seismic performance ,Computer science ,0211 other engineering and technologies ,020101 civil engineering ,02 engineering and technology ,Kinematics ,0201 civil engineering ,Seismic analysis ,cladding panels ,Precast concrete ,medicine ,precast concrete ,sliding connections ,isostatic system ,experimental testing ,Civil and Structural Engineering ,021110 strategic, defence & security studies ,Normal force ,business.industry ,Seismic loading ,Stiffness ,Building and Construction ,Structural engineering ,Decoupling (cosmology) ,Geotechnical Engineering and Engineering Geology ,Cladding (fiber optics) ,Geophysics ,precast concrete, cladding panels, sliding connections, isostatic system, seismic performance, experimental testing ,medicine.symptom ,business - Abstract
The traditional seismic design of precast frame buildings concerns the calculation of the frame, considering the cladding panels as non-structural added masses without stiffness, assuming they are connected so to not interact with the frame. Under seismic excitation, the cladding connections are subjected to complex multi-directional actions, depending on the panel static scheme, all of which involve relative motion between cladding and structure. The correct kinematics of these connections in decoupling the panels from the structure has rarely been demonstrated, and accidental coupling may result in dangerous sudden increase of forces and subsequent failure of the connections. This is also confirmed by post-earthquake field observations on precast structures, which are characterised by pronounced deformation under seismic loading due to their flexibility. An innovative panel-to-structure sliding connection conceived to allow for an effective cladding-structure decoupling has been tested to check its correct kinematics within a uniaxial test apparatus, imposing displacement histories with application of constant normal force. The experimental results of cyclic tests with a tailored test protocol are presented, and static and dynamic friction coefficients are experimentally evaluated. A cyclic test on a full-scale precast prototype equipped with sliding panel connections has been carried out, checking the global behaviour of such systems and their installation peculiarities. Design rules for the evaluation of seismic actions arising within the proposed panel arrangements are finally provided, accounting for the experimentally evaluated friction coefficients.
- Published
- 2018
30. Experimental tests on multiple-slit devices for precast concrete panels
- Author
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Fabio Biondini, Bruno Dal Lago, and Giandomenico Toniolo
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021110 strategic, defence & security studies ,Materials science ,Concrete panels ,Friction ,Plasticity ,business.industry ,Energy dissipation ,0211 other engineering and technologies ,Precast structures ,Experimental testing ,020101 civil engineering ,02 engineering and technology ,Structural engineering ,Dissipation ,Slit ,Displacement (vector) ,0201 civil engineering ,Cable gland ,Civil and Structural Engineering ,Precast concrete ,Dissipative system ,Steel plates ,business - Abstract
Multiple Slit Devices (MSDs) are plasticity-based dissipative connectors consisting of steel plates provided with slits which lead to a set of elementary beams. In this way, the shear-type behavior of the plate is turned into the flexural-type behavior of the elementary beams, which ensures better energy dissipation. The proposed MSDs are bolted to support steel profiles inserted into appropriate recesses in between precast concrete panels to improve the seismic performance of the earthquake-resisting system. The paper presents the results of monotonic and cyclic experimental tests performed on both connectors and structural sub-assemblies consisting of two full-scale precast concrete panels connected by a MSD. Steel plates with slits of various shape and size are considered. An improved version of the connector capable to dissipate energy through both plasticity and friction and to provide enhanced displacement capacity is also proposed and tested.
- Published
- 2018
31. Assessment of a capacity spectrum seismic design approach against cyclic and seismic experiments on full-scale precast RC structures
- Author
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Bruno Dal Lago and Francisco Javier Molina
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021110 strategic, defence & security studies ,Full-scale experimentation ,business.industry ,0211 other engineering and technologies ,Full scale ,Precast structures ,Seismic design ,Performance-based approach ,Energy approach ,Capacity spectrum ,020101 civil engineering ,02 engineering and technology ,Structural engineering ,Geotechnical Engineering and Engineering Geology ,0201 civil engineering ,Seismic analysis ,Precast concrete ,Earth and Planetary Sciences (miscellaneous) ,business ,Geology ,Civil and Structural Engineering ,Seismic design, Performance-based approach, Energy approach, Capacity spectrum, Precast structures, Full-scale experimentation - Published
- 2018
32. Verso elementi in calcestruzzo armato precompresso senza acciaio: uno studio sperimentale
- Author
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Bruno Dal Lago, Liberato Ferrara, Deegan, Peter, Taylor, Susan, Sonebi, Mohammed, and Pattarini, Andrea
- Published
- 2017
33. Full-scale testing and numerical analysis of a precast fibre reinforced self-compacting concrete slab pre-stressed with basalt fibre reinforced polymer bars
- Author
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Su E. Taylor, Bruno Dal Lago, Liberato Ferrara, Philip Crosset, Andrea Pattarini, Mohammed Sonebi, and Peter Deegan
- Subjects
Materials science ,0211 other engineering and technologies ,02 engineering and technology ,computer.software_genre ,Industrial and Manufacturing Engineering ,Load testing ,Flexural strength ,Precast concrete ,021105 building & construction ,Limit state design ,Composite material ,Basalt Fibre Reinforced Polymer (BFRP) bars ,Creep losses ,Fibre Reinforced Self-Compacting Concrete (FRSCC) ,Non-linear analysis ,Steel-free beams ,Visco-elastic analysis ,Ceramics and Composites ,Mechanics of Materials ,Mechanical Engineering ,business.industry ,Structural engineering ,021001 nanoscience & nanotechnology ,Strength of materials ,Durability ,Reinforced solid ,Slab ,0210 nano-technology ,business ,computer - Abstract
Steel-free pre-stressed reinforced concrete may be used in aggressive environments to increase the durability of structural elements and to limit the carbon footprint by replacing steel with high-strength fibre composites. The design of a 10-m long steel-free precast fibre-reinforced concrete slab, pre-stressed with basalt-fibre reinforced polymer (BFRP) bars and shear-reinforced with glass-fibre reinforced polymer bars, is presented in this paper. Non-linear viscoelastic and elastic-plastic models have been employed for the prediction of the service and ultimate limit state flexural behaviour, respectively. Preliminary tests on the employed materials and a 3-point load test on the slab element are presented, together with indications on its manufacturing process. The proposed numerical analysis is validated against the experimental results.
- Published
- 2017
- Full Text
- View/download PDF
34. Structural behavior of longitudinally posttensioned timber beams under serviceability gravity loading
- Author
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Andrew H. Buchanan, Claudio Dibenedetto, Stefano Pampanin, David Carradine, Alessandro Palermo, Bruno Dal Lago, and Simona Giorgini
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timber construction ,Engineering ,Serviceability (structure) ,Long-span beams ,numerical analysis ,business.industry ,020209 energy ,Mechanical Engineering ,wood structures ,posttensioning ,serviceability ,02 engineering and technology ,Building and Construction ,Structural engineering ,Post-tensioning, Timber construction, Long-span beams, Serviceability, Numerical analysis ,Mechanics of Materials ,0202 electrical engineering, electronic engineering, information engineering ,General Materials Science ,Post-tensioning ,Timber construction ,Serviceability ,Numerical analysis ,business ,Civil and Structural Engineering - Abstract
The scope of this paper is to quantify the advantages of using unbonded longitudinal posttensioning for long-span timber beams. This sustainable system can be a suitable alternative to more...
- Published
- 2017
35. An experimental study towards steel-free precast concrete elements
- Author
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Deegan, Peter, Taylor, Susan E., Sonebi, Mohammed, Liberato Ferrara, Bruno Dal Lago, and Pattarini, Andrea
- Published
- 2017
36. End support connection of precast roof elements by bolted steel angles
- Author
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Giandomenico Toniolo, Marco Lamperti Tornaghi, Roberto Felicetti, and Bruno Dal Lago
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Engineering ,mechanical connections ,seismic performance ,0211 other engineering and technologies ,020101 civil engineering ,02 engineering and technology ,Welding ,0201 civil engineering ,law.invention ,law ,Precast concrete ,11. Sustainability ,medicine ,General Materials Science ,floor-to-beam joint ,Roof ,Civil and Structural Engineering ,021110 strategic, defence & security studies ,Precast structures ,steel angles ,experimental testing ,business.industry ,Precast structures, mechanical connections, floor-to-beam joint, steel angles, seismic performance, experimental testing ,Stiffness ,Vertical plane ,Building and Construction ,Structural engineering ,Structural load ,Mechanics of Materials ,Seismic retrofit ,medicine.symptom ,business ,Relative displacement - Abstract
Steel angles are extensively used to connect concrete floor/roof elements to the supporting beam in typical dry-assembled precast frame structures widely diffused in Europe and other parts of the world. These connections allow for relative rotations of the floor element in its vertical plane and restrain their relative displacement, avoiding possible loss of support and consequent fall of the floor element when the structure is subjected to lateral load. The diaphragm behavior of the precast decks relies on these floor-to-beam connections. Their postaddition to unconnected floor-to-beam joints of existing buildings is a typical seismic retrofit intervention. All these applications are often made without any adequate information about the main structural parameters of the connections due to lack of experimental or theoretical knowledge. An experimental campaign has been performed at Politecnico di Milano within the framework of the Safecast and ReLUIS research projects with the scope of characterizing the mechanical behavior of postinserted floor-to-beam connections made with hot-rolled angles, cold-formed angles, and welded sockets in the direction parallel to the floor element. The results of monotonic local tests on connectors and on the bolted connection with the floor rib and of cyclic and monotonic subassembly tests allowed the determination of the main structural parameters of the joints, including elastic stiffness, strength, displacement capacity, and hysteretic shape.
- Published
- 2017
37. Numerical and experimental analysis of an innovative lightweight precast concrete wall
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Liberato Ferrara, M. Muhaxheri, and Bruno Dal Lago
- Subjects
021110 strategic, defence & security studies ,Engineering ,Full-scale experimentation ,Bearing panels ,business.industry ,Precast concrete ,Wall connections ,Non-linear modelling ,Seismic performance ,Damage-sensitive elements ,Pseudo-dynamic testing ,0211 other engineering and technologies ,Full scale ,020101 civil engineering ,02 engineering and technology ,Structural engineering ,0201 civil engineering ,Flexural strength ,Precast concrete, Bearing panels, Wall connections, Non-linear modelling, Seismic performance, Damage-sensitive elements, Pseudo-dynamic testing, Full-scale experimentation ,business ,Ductility ,Beam (structure) ,Civil and Structural Engineering - Abstract
A series of non-linear structural analyses is presented in this paper, aimed at investigating the structural behaviour of an innovative light-weight precast concrete wall system made with discretely connected moduli. A model with 2D damage-sensitive elements has been used to investigate the axial and flexural behaviour of a case study wall element. The numerical analyses allow to estimate the crack pattern and to define monotonic capacity curves. The effect of different reinforcement schemes on the structural behaviour of the wall has been also investigated and an innovative solution has been also proposed on the basis of the results, to increase the ductility of a heavily shear-reinforced wall when subjected to seismic action. The numerical results obtained with the 2D damage model have been compared with those of a simplified non-linear beam model. Furthermore, the effectiveness of the simplified model in catching the dynamic non-linear behaviour of the element has been validated with respect to the results from pseudo-dynamic tests performed at the ELSA/JRC laboratory of Ispra (Italy) in the framework of the Safecast project on a full scale prototype of a multi-storey precast building braced by the walls under investigation.
- Published
- 2017
38. Experimental and numerical investigation on an innovative wing-shaped precast floor element of exceptional span / Studio sperimentale e numerico di un tegolo alare prefabbricato innovativo di luce eccezionale
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Bruno Dal Lago Alberto Dal Lago Uberto Marchetti Angelo, Basso.
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modellazione semi-analitica ,precast concrete ,grande luce ,experimental testing ,prove sperimentali ,long span ,semi-analytical modelling - Published
- 2016
39. Role of Wall Panel Connections on the Seismic Performance of Precast Structures
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Giandomenico Toniolo, Fabio Biondini, and Bruno Dal Lago
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Engineering ,business.industry ,Structural system ,Hinge ,Stiffness ,Building and Construction ,Structural engineering ,Geotechnical Engineering and Engineering Geology ,Seismic analysis ,Cladding (construction) ,Nonlinear system ,Geophysics ,Precast concrete ,Dissipative system ,medicine ,medicine.symptom ,business ,Civil and Structural Engineering - Abstract
Past seismic events, including the 2009 L’Aquila earthquake and the 2012 Emilia earthquake, clearly demonstrated the inadequacy of the current design approach for the connection system of the cladding wall panels of precast buildings. To clarify this problem the present paper investigates the seismic behaviour of a traditional precast structural frame for industrial buildings with a new type of connection system of cladding panels. This system consists of a statically determined pendulum arrangement of panels, each supported with two hinges to the structure, one at the top and one at the bottom, so to have under seismic action a pure frame behaviour where the wall panels are masses without stiffness. Adding mutual connections between the panels, the wall cladding panels become part of the resisting structure, leading to a dual frame/wall system or to a wall system depending on the stiffness of the connections. The seismic behaviour of this structural assembly is investigated for different degrees of interaction between frame and panels, as well as for an enhanced solution with dissipative connections. The results of nonlinear static (pushover) analyses and nonlinear dynamic analyses under recorded and artificial earthquakes highlight the role of the wall panel connections on the seismic behaviour of the structural assembly and show the effectiveness of the dual frame/wall system with dissipative connections between panels.
- Published
- 2013
40. Experimental identification of the shear failure modes of a voided precast wall element subjected to lateral loading
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P Bamonte, L. Coppola, Bruno Dal Lago, Del Galdo, M., Dal Lago, A., and Liberato Ferrara
41. Structural vulnerability of old precast building stock: case studies from the period 1940s-1970s
- Author
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P Bamonte, L. Coppola, Bruno Dal Lago, Berretta, E., and Liberato Ferrara
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