{"title":"OPTIMAL RETROFIT SELECTION FOR SEISMICALLY-DEFICIENT RC BUILDINGS BASED ON SIMPLIFIED PERFORMANCE ASSESSMENT","authors":"R. Gentile, C. Galasso","doi":"10.7712/120119.6986.19675","DOIUrl":"https://doi.org/10.7712/120119.6986.19675","url":null,"abstract":"This study deals with the selection of optimal retrofit solutions for seismically-deficient Reinforced Concrete (RC) buildings. To this aim, Multi-Criteria Decision-Making (MCDM) analysis is used. A discussion on the retrofit design strategy is first presented, recommending \u0000designing each retrofit solution for the same expected damage state under the design-level \u0000earthquake-induced ground-motion spectrum. Secondly, it is argued to explicitly consider seismic economic losses as a decision criterion. To this aim, seismic fragility/vulnerability relationships are derived for the structure of interest retrofitted with different techniques and \u0000considering a large suite of ground-motion records. Simplified-yet-accurate non-linear static \u0000procedures are used as an alternative to non-linear time-history analysis to reduce the challenges in building detailed numerical models, computational demand, and results interpretation. Specifically, three increasingly-refined structural analysis methods are adopted to derive \u0000fragility/vulnerability curves: the Simple Lateral Mechanism Analysis (SLaMA), which is an \u0000analytical approach; numerical pushover; and non-linear time-history analysis. A seismicallydeficient RC school index building, with construction details typical of developing countries, is \u0000used for illustrative purposes. The case-study structure is retrofitted through concrete jacketing, addition of concrete walls, and addition of steel braces, all designed through Direct Displacement-Based Design. The MCDM analysis is performed adopting, among other criteria, \u0000intensity-based losses derived with the three considered analysis methods, using state-of-theart, advanced ground-motion intensity measures. The results show that the ranking of the retrofit alternatives is rather insensitive to the adopted analysis method, even if the considered \u0000weight for the seismic loss criterion is relatively high (30% in this example). Findings from this \u0000study suggest that simplified analysis methods can be effectively employed in the preliminary/conceptual design of retrofit solutions for seismically-deficient buildings.","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123704188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"MACROSCALE MODEL CALIBRATION FOR SEISMIC ASSESSMENT OF BRICK/BLOCK MASONRY STRUCTURES","authors":"C. Chisari, L. Macorini, B. Izzuddin","doi":"10.7712/120119.7003.19161","DOIUrl":"https://doi.org/10.7712/120119.7003.19161","url":null,"abstract":"The accurate prediction of the response of masonry structures under seismic loading is one of the most challenging problems in structural engineering. Detailed heterogeneous models at the mesoor microscale, explicitly allow for the specific bond and, if equipped with accurate material models for the individual constituents, generally provide realistic response predictions even under extreme loading conditions, including earthquake loading. However, detailed mesoor microscale models are very computationally demanding and not suitable for practical design and assessment. In this respect, more general continuum representations utilising the finite element approach with continuum elements and specific macroscale constitutive relationships for masonry assumed as a homogeneous material represent more efficient but still accurate alternatives. In this research, the latter macroscale strategy is used to model brick/block masonry components structures, where a standard damage-plasticity formulation for concrete-like materials is employed to represent material nonlinearity in the masonry. The adopted material model describes the softening behaviour in tension and compression as well as the strength and stiffness degradation under cyclic loading. An effective procedure for the calibration of the macroscale model parameters is presented and then used in a numerical example. The results achieved using the calibrated macroscale model are compared against the results of simulations where masonry is modelled by a more detailed mesoscale strategy. This enables a critical appraisal of the ability of elasto-plastic macroscale nonlinear representations of masonry modelled as an isotropic homogenised continuum to represent the response of masonry components under in-plane and out-of-plane earthquake loading.","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"731 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115130400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"ANALYSIS OF METAL CONNECTOR’S EFFECT ON SEISMIC RESISTANCE OF DRY STONE-MASONRY STRUCTURES","authors":"Ž. Nikolić, H. Smoljanović, N. Živaljić","doi":"10.7712/120119.6997.18926","DOIUrl":"https://doi.org/10.7712/120119.6997.18926","url":null,"abstract":"In this work, numerical investigations of the behaviour of dry stone masonry structures, reinforced with metal connectors (clamps and dowels), were performed by the finite-discrete element model for strengthened dry-stone masonry structures. The geometrical and material model of the metal connectors were developed and implemented into the finite-discrete element model in order to analyse the influence of the connectors to strengthening capacity of the structure. The yielding and extracting of the connectors (clamps and dowels) from the holes were represented by experimental force-displacement curves, obtained by testing the samples composed of two stone blocks connected with clamps or dowels. An incremental dynamic analysis up to the structural failure was applied in order to determine failure mechanisms and collapse load. The results were compared to those obtained for unreinforced structures. The results show the performance of the applied model in simulation of the behaviour of historical monuments, composed of stone blocks with dry joints and connectors, in the dynamic regime. The model is complex and time consuming, but it can be useful for making decisions related to reconstruction and increasing the earthquake resistance of the historical buildings.","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"75 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120915036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"APPLIED ELEMENT MODELLING AND PUSHOVER ANALYSIS OF UNREINFORCED MASONRY BUILDINGS WITH FLEXIBLE ROOF DIAPHRAGM","authors":"R. Adhikari, D. D’Ayala","doi":"10.7712/120119.7189.19990","DOIUrl":"https://doi.org/10.7712/120119.7189.19990","url":null,"abstract":"Old and poorly constructed unreinforced masonry buildings are inherently vulnerable to earthquakes. Seismic analysis and assessment of these buildings with flexible diaphragmsi.e. without \u0000box behavior is challenging as the available assessment methods for reinforced concrete \u0000framed or masonry structures with rigid diaphragms are not directly applicable to these buildings. In such structures, the walls loaded in out-of-plane direction and those loaded in in-plane \u0000direction behave in significantly different ways during earthquakes, making a conventional \u0000global analysis ambiguous and unreliable. In this study, using the applied element method for \u0000numerical modelling and analysis, a simple and reliable methodology for seismic performance \u0000assessment of unreinforced masonry buildings with flexible roof diaphragm is presented which \u0000includes the out-of-plane behavior in the global analysis. The applicability of the methodology \u0000for subsequent steps in fragility and vulnerability assessment of such buildings using non-linear \u0000static procedures is also clarified.","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115668167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Sarno, J.R. Wu, M. D’Aniello, S. Costanzo, R. Landolfo, O. Kwon, F. Freddi
{"title":"ASSESSMENT OF EXISTING STEEL FRAMES WITH INFILLS UNDER MULTIPLE EARTHQUAKES","authors":"L. Sarno, J.R. Wu, M. D’Aniello, S. Costanzo, R. Landolfo, O. Kwon, F. Freddi","doi":"10.7712/120119.7347.19837","DOIUrl":"https://doi.org/10.7712/120119.7347.19837","url":null,"abstract":"Many existing steel multi-storey frames in Europe were designed prior to the provisions of \u0000modern seismic design codes; therefore, they often exhibit low resistance to earthquakes due \u0000to their insufficient energy dissipation capacity. However, the current framework for assessing existing structures in EC8-3 is inadequate and should be reviewed. Particular attention should be paid to the contribution from masonry infill walls as they significantly affect \u0000the modal properties and the lateral stiffness of structures. To this end, two 3D models of a \u0000two-storey steel moment-resisting frame were developed to assess the applicability of the current framework in EC8-3 to the infilled structures under multiple earthquakes through nonlinear analyses. The modelling of masonry infill walls was achieved through a macro-model \u0000using equivalent diagonal struts. The ground motions utilised during the analyses took the \u0000records of the recent 2016 Central Italy earthquake sequence. As part of the project \u0000HITFRAMES, this paper serves as a preparation for the experiment to be conducted in \u0000Greece.","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114211136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"MANAGING EMERGENCY INTO HISTORIC CENTRES IN ITALY: SEISMIC VULNERABILITY EVALUATION AT URBAN SCALE","authors":"A. Falco, F. Giuliani, V. Cutini, Sevieri Giacomo","doi":"10.7712/120119.7025.19088","DOIUrl":"https://doi.org/10.7712/120119.7025.19088","url":null,"abstract":"Italy is one of the most earthquake prone areas in Europe and one of the countries with the richest cultural legacy in the world. A series of seismic events occurred in the last decades caused considerable casualties and damage to historic centres, highlighting the need of undertaking protective measures to limit the impact of any potential earthquake. The complex morphology of historical city centres with their century-old built environment contribute to the high vulnerability and exposure in the areas. This research introduces an interdisciplinary approach to implement the seismic emergency management for historical centres in Italy and consequently to address their preventive planning. A procedure combining vulnerability analysis and urban spatial techniques allows defining a ranking of priority interventions to be included into a preventive plan in order to ensure free escape routes and clear access for the emergency services during the post-seismic phase. The first step of this work is the survey of the present-day configuration of historic centres, with their historical assets, aggregates, critical infrastructures, urban functions and strategic activities. Then, a key aspect regards the vulnerability assessment of the urban fabric in order to predict post-seismic damage scenarios. By considering the interference of the buildings' vulnerability with the street network, it is possible to develop mitigation strategies to improve the emergency management.","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115237089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Penava, Filip Anić, V. Sarhosis, L. Abrahamczyk
{"title":"DISTRIBUTION OF SHEAR RESISTANCE AMONG COMPONENTS OF R. C. FRAMES WITH MASONRY INFILL WALLS CONTAINING CONFINED DOOR AND WINDOW OPENINGS","authors":"D. Penava, Filip Anić, V. Sarhosis, L. Abrahamczyk","doi":"10.7712/120119.7084.18488","DOIUrl":"https://doi.org/10.7712/120119.7084.18488","url":null,"abstract":"In earthquake resistant design of r. c. frame structures with unreinforced masonry infill walls, containing different in size and position window and door openings, confining elements (tie-columns) are crucial component of seismic detailing of the structure. Having construction of the masonry infill wall without confining elements along opening edges, seismic response prediction becomes unreliable, due to uncontrolled sequenced failure mode of masonry infill walls, its out-of-plane instability, unfavorable crack distribution and premature and total dis-integration. Confining elements are not subdued to design as moment-resisting r. c. frames and their construction details are based on simple recommendations. The aim of this study is, by usage of calibrated computational micromodel in computer program ATENA 2D Eng, to determine the shear resistance distribution among components of r. c. frames with masonry infill walls, containing confined door and window openings, at damage grades in compliance with EMS-98 scale.","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116646633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"SOIL-STRUCTURE INTERACTION MODELING FOR THE DYNAMIC ANALYSIS OF CONCRETE GRAVITY DAMS","authors":"A. Falco, M. Mori, G. Sevieri","doi":"10.7712/120119.7335.19130","DOIUrl":"https://doi.org/10.7712/120119.7335.19130","url":null,"abstract":"During earthquake shaking, the dam-reservoir-foundation system has to be considered a coupled system. In this paper Soil-Structure Interaction (SSI) effect is investigated on a 2D plane model of a concrete gravity dam under earthquake excitation. Firstly, different approaches to simulate the unboundedness of soil domain are explored: the Perfectly Matched Layer (PML) technique, the Low Reflecting Boundary (LRB) condition and the Infinite Elements (IEs). Different options are compared in the time domain in the case of linear elastic material. The importance of taking into account the SSI in the seismic assessment of concrete dams is also highlighted by the energy balance during time. Successively, the effects of SSI are analysed on a full interacting nonlinear plane model. The results which are obtained in terms of material damage and dissipated energy through a parametric SSI simulation in the time domain show the importance of the choice of the damage constitutive law of the material.","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131779178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"DRIVE-BY DAMAGE MONITORING OF TRANSPORT INFRASTRUCTURE USING DIRECT CALCULATION OF THE PROFILE","authors":"J. Keenahan, E. O'brien, Yifei Ren","doi":"10.7712/120119.7195.19433","DOIUrl":"https://doi.org/10.7712/120119.7195.19433","url":null,"abstract":"COMPDYN 2019: 7th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering, Crete, Greece, 24-26 June 2019","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125928577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Alotaibi, G. Thermou, I. Hajirasouliha, M. Guadagnini
{"title":"TENSILE BEHAVIOUR OF MULTI-PLY STEEL- REINFORCED GROUT (SRG) COMPOSITES","authors":"S. Alotaibi, G. Thermou, I. Hajirasouliha, M. Guadagnini","doi":"10.7712/120119.6985.19504","DOIUrl":"https://doi.org/10.7712/120119.6985.19504","url":null,"abstract":"Steel Reinforced Grout (SRG) composites consist of Ultra High Tensile Strength Steel (UHTSS) fabrics embedded in an inorganic mortar matrix. The use of SRG for the repair and retrofitting of deficient structures has emerged as a novel technique in the last few years. This paper discusses the results of a comprehensive experimental study on the tensile behaviour of multiply SRG composites. A total of 24 direct tensile tests were conducted on SRG coupons to assess the influence of the fabric’s layout and architecture on cracking and overall tensile behaviour. Two main parameters were investigated, including the number of fabric layers (1, 2, and 3 layers) and the density of the steel fabric (4 and 8 cords/in). It was found that, although the grout contribution is significant up until failure regardless of the number of layers, the ultimate strength of the composite is generally governed by the ultimate strength of the fabric. The large amount of densely distributed cracks that developed throughout the length of the coupons suggests that a good bond could develop between the fabric and the grout, possibly as a result of the geometry of the twisted cords and the development of good mechanical interlock.","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"169 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132789673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}