Antonio Gaspari, Roberto Modena, I. Giongo, M. Piazza
{"title":"Vulnerability analysis on a dataset of long-span timber structures in Italy","authors":"Antonio Gaspari, Roberto Modena, I. Giongo, M. Piazza","doi":"10.1680/jstbu.21.00200","DOIUrl":"https://doi.org/10.1680/jstbu.21.00200","url":null,"abstract":"Long-span structures, such as school gyms and sports centres, are often used by the Italian Department of Civil Protection (DPC) as post-catastrophe shelters or headquarters. The Emilia 2012 earthquake drew the attention of the DPC to this type of structure due to the damage that many of these buildings suffered. In this paper, a dataset of 101 timber structures was analysed based on a simplified methodology that detects the major vulnerabilities in long-span timber roofs to help planning further investigations and retrofit interventions. The methodology analyses the elements most vulnerable to the seismic action quantitatively and qualitatively, with fast and straightforward approaches. The quantitative evaluation of the vulnerabilities was achieved by applying the Italian Building Code. The aspects not considered in the quantitative evaluation were instead assessed through qualitative parameters inspired by damage identification forms, such as the AeDES form. The structures analysed are located near the epicentres of the last strong earthquakes that struck Italian territory: Abruzzo 2009, Emilia 2012, and central Italy 2016. Damage and retrofits, identified by interviewing owners, designers, and builders, showed a good correlation between the real behaviour shown by the surveyed structures and the vulnerabilities detected by the simplified methodology.","PeriodicalId":54570,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Structures and Buildings","volume":"1 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79789966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of loss of bond on flat-slab building collapses","authors":"G. Kotsovos, E. Vougioukas, M. Kotsovos","doi":"10.1680/jstbu.22.00224","DOIUrl":"https://doi.org/10.1680/jstbu.22.00224","url":null,"abstract":"Between 1997 and 2010, there has been a small, yet unexpected number of flat slab car-park buildings, which collapsed under service loading. In all cases, the collapse was preceded by loss of bond between concrete and flexural reinforcement. All investigations of the causes of these collapses have since been inconclusive, particularly as regards the effect of loss of bond. Yet, loss of bond due to yielding of the flexural reinforcement in tension had already been proposed as the main cause of punching and failure criteria derived on the basis of this proposal were found to produce predictions which correlated closely with experimentally-established values of the punching failure load. The present work is intended to extend the range of application of these criteria to the case of loss of bond due to steel corrosion and test their validity against the available information on the car-park building collapses.","PeriodicalId":54570,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Structures and Buildings","volume":"38 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72773958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"ANNA: Advanced neural network algorithm for optimization of structures","authors":"N. Khodadadi, S. Talatahari, A. Gandomi","doi":"10.1680/jstbu.22.00083","DOIUrl":"https://doi.org/10.1680/jstbu.22.00083","url":null,"abstract":"The purpose of this study is to develop an advanced neural network algorithm (ANNA) as a new optimization for the optimal design of truss structures. The central concept of the algorithm is based on biological nervous structures and artificial neural networks. The performance of the proposed method is explored in engineering design problems. Two efficient methods for improving the standard Neural Network Algorithm (NNA) are regarded here. The first one is an enhanced initialization mechanism based on opposite-based learning. The second one is on using a few tunable parameters to provide proper exploration and exploitation abilities for the algorithm that causes finding better solutions while the required structural analyses are reduced. The new algorithm's performance is investigated by using five well-known restricted benchmarks to assess its efficiency concerning the latest optimization techniques. The outcome of the examples demonstrates that the upgraded version of the algorithm has increased efficacy and robustness in comparison to the original version of the algorithm and to some other methods.","PeriodicalId":54570,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Structures and Buildings","volume":"40 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89615910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Energy based assessment of the reinforced concrete walls with two outriggers","authors":"H. Beiraghi, Ebrahim Momen Abadi","doi":"10.1680/jstbu.21.00046","DOIUrl":"https://doi.org/10.1680/jstbu.21.00046","url":null,"abstract":"In this paper, different kind of energy dissipation in reinforced concrete (RC) core-wall systems with two buckling-restrained braced outriggers subjected to forward directivity near-fault and ordinary far-fault earthquakes has been compared. The level of the first outrigger is fixed at the top and the second outrigger is placed at different levels. In the nonlinear model, two approaches for the RC core-wall were considered: extended plastic hinge (EPH) approach and 4 plastic hinges approach (4PH). In 4PH approach, only 4 plastic hinges are allowed in the RC core-wall, one at the base, one another adjacent beneath the top outrigger, and two others at the levels adjacent second outrigger. For EPH approach, the plasticity can extend anywhere in the core-wall. Principally for the EPH approach, at the base of core-wall and adjacent to top outrigger as well as above and below of second outrigger level, more inelastic energy demands are occurred due to large moment demand resulting from seismic load. On average for both EPH and 4PH approaches, the inelastic energy at the base from far-fault records is almost 1.5 times the corresponding value from NF records.","PeriodicalId":54570,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Structures and Buildings","volume":"35 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89728636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jung-Yoon Lee, Na-Yeong Kim, Dongik Shin, Hyung-woo Byun, Kil-Hee Kim
{"title":"Torsional strength limitation of reinforced concrete beams","authors":"Jung-Yoon Lee, Na-Yeong Kim, Dongik Shin, Hyung-woo Byun, Kil-Hee Kim","doi":"10.1680/jstbu.22.00099","DOIUrl":"https://doi.org/10.1680/jstbu.22.00099","url":null,"abstract":"In order to promote yielding of stirrups prior to concrete crushing and avoid the over-reinforced failure modes in reinforced concrete (RC) members, the current design codes stipulate limits on the maximum amount of shear and torsional reinforcement. Studies show that the shear strength limits introduced based on the plane-truss approach estimate the maximum shear strength and shear failure mode with reasonable accuracy. However, the torsional strength limits which are derived based on the space truss analogy and thin-walled tube theory, generally overestimate the maximum torsional strength. In this study, the difference between the limiting values introducing the current design codes on the maximum shear and torsional strengths was evaluated by analyzing the test results of 406 shear and 153 torsional members. Additionally, experimental tests were conducted on 22 RC beams subjected to torsional moments to directly measure the strain rate of the web concrete and investigate the torsional strength limit values. The results indicate that f the torsional strength limit values derived based on the space truss model overestimate the actual maximum torsional strength. Based on these observations, a lower limiting value for the maximum torsional strength is proposed to avoid over-reinforced torsional failure","PeriodicalId":54570,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Structures and Buildings","volume":"44 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78736099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Modelling bond in concrete with steel and carbon-fibre-reinforced-polymer composite bars","authors":"Lei Wang, Junwen Chen, N. Shen, F. Fu","doi":"10.1680/jstbu.22.00090","DOIUrl":"https://doi.org/10.1680/jstbu.22.00090","url":null,"abstract":"Understanding the bonding stress distribution and reinforcement strain distribution between steel and carbon-fibre-reinforced-polymer composite bars and concrete is essential to the design of concrete reinforced with such bars. Currently, the bond stress and reinforcement strain distribution patterns are not clear. Therefore, a series of pull-out tests was undertaken on concrete reinforced with steel and carbon-fibre-reinforced-polymer composite bars, carbon-fibre-reinforced-polymer bars and steel bars. With the help of a fibre Bragg grating sensing technology, the reinforcement strain and bonding stress distribution was studied. The results showed that for all specimens, the bond stress between the reinforcement and concrete was neither uniformly distributed nor reduced linearly along the bond length. For the steel and fibre-reinforced-polymer composite reinforcement, the steel core strain value was less than the carbon fibre strain value at the same position. Based on the test results, a bonding stress model and bond stress distribution model were established. The two models agreed well with the test data and can be used to predict bond stress and bond stress distribution.","PeriodicalId":54570,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Structures and Buildings","volume":"18 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86727304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mechanical properties of axially and eccentrically loaded CFRP-coral concrete columns","authors":"Shuang Chen, Jiwen Guan, Shujia Liang","doi":"10.1680/jstbu.22.00134","DOIUrl":"https://doi.org/10.1680/jstbu.22.00134","url":null,"abstract":"The eccentrically loaded bearing capacity tests on 6 CFRP reinforced coral concrete short columns were carried out. Parameters such as the ultimate bearing capacities, the stress of CFRP bars and surface concrete were measured and analyzed. The results showed that all the columns failed due to the crushing of concrete in the compression zone. Meanwhile, the increase of eccentricity not only decreased the ultimate bearing capacity, but also resulted in the shear fracture of CFRP longitudinal bars in compression zone. In general, the stress of longitudinal CFRP reinforcements in all specimens were always in quite low level. The maximum stress of CFRP bars in columns was just 105.78 MPa, only 23.5% of the ultimate compressive strength of CFRP reinforcement. The superior bonding performance between the CFRP bars and coral concrete conformed to the deformation coordination. Subsequently, the calculation method for bearing capacity of CFRP-coral concrete short columns was put forward, and the calculated results agreed well with the tested results.","PeriodicalId":54570,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Structures and Buildings","volume":"2 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73027900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Flexural behavior of high-strength stainless steel wire rope reinforced ECC slabs","authors":"Xin-Ling Wang, Yaokang Zhao, Wenwen Qian, Yongjie Chen, Ke Li, Juntao Zhu","doi":"10.1680/jstbu.22.00097","DOIUrl":"https://doi.org/10.1680/jstbu.22.00097","url":null,"abstract":"Engineered cementitious composites (ECC) features ultra-high ductility and multiple-cracking properties. High-strength stainless steel wire rope (HSSSWR) exhibits high tensile strength and good corrosion resistance. Taking advantage of these two materials, HSSSWR reinforced ECC (HSSSWR-ECC) promises to be attractive materials when used in flexible and ductile link slabs in the bridge deck system, permanent formwork of concrete members and strengthening of existing members. To investigate the flexural behavior of HSSSWR-ECC slabs, bending tests were performed on HSSSWR-ECC slabs with different reinforcement ratios of HSSSWRs and ECC formulas. Test results show that HSSSWR-ECC slabs exhibit excellent crack-width control and deformation capacities under bending moment. Increasing the HSSSWRs reinforcement ratio can enhance the flexural capacity of HSSSWR-ECC slabs, but would reduce the ductility. Adding thickeners in ECC could enhance the crack-width control ability and ductility of HSSSWR-ECC slabs by improving the Polyvinyl Alcohol (PVA) fiber dispersion in ECC, but would reduce the flexural capacity by reducing ECC strength. Calculation formulas for predicting flexural capacity of HSSSWR-ECC slabs were proposed based on related mechanics theories. The accuracy of the proposed calculation formulas was verified by comparing with test results and predicted results using the finite numerical model for HSSSWR-ECC slabs developed in this paper.","PeriodicalId":54570,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Structures and Buildings","volume":"34 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91337186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Corrosion depth of steel bars in recycled aggregate concrete beams under static load","authors":"Jian Wang, Han Su, Jinsheng Du","doi":"10.1680/jstbu.21.00035","DOIUrl":"https://doi.org/10.1680/jstbu.21.00035","url":null,"abstract":"To study the distribution of corrosion depth along the longitudinal direction of tensile steel bars embedded in recycled aggregate concrete (RAC) beams under static loads, a total of twelve RAC beams were designed for accelerated corrosion test by considering three types of recycled coarse aggregate (RCA) replacement ratios (i.e., 0%, 50%, and 100%) and four kinds of static load levels (i.e., 0, 0.2, 0.4, and 0.6). The results demonstrated that the corrosion depth of tensile reinforcement showed an increasing trend with the increase of static load level. The maximum corrosion depth had a good quadratic polynomial relationship with the average corrosion depth of tensile reinforcement and increased with the average corrosion depth. For the beams with same RCA replacement ratio, there was a good linear relationship between the overall uneven corrosion coefficient and average mass loss of tensile reinforcement. The probability distribution type of corrosion depth along the longitudinal direction of tensile reinforcement was mainly lognormal distribution. An increase in both RCA replacement ratio and static load level could make the probability distribution curve of corrosion depth moving to the right and also increase the dispersion of corrosion depth around its mean value.","PeriodicalId":54570,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Structures and Buildings","volume":"61 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90096065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Multi-hazard performance evaluation of hillside buildings under earthquake and landslide","authors":"Mahipal Kulariya, S. Saha","doi":"10.1680/jstbu.22.00132","DOIUrl":"https://doi.org/10.1680/jstbu.22.00132","url":null,"abstract":"Earthquake-induced landslide, a cascading hazard in the hilly region, can substantially increase the damaging effects of an earthquake. This necessitates the performance evaluation of the buildings situated in the hilly region under landslide-only and landslide following earthquake. The present study assesses the performance of two commonly observed hillside building configurations, i.e., step-back and split foundation, subjected to the above-mentioned multi-hazard scenarios using an uncoupled approach. The uncertainty in the soil properties, which influence the landslide-induced forces, is considered based on laboratory tests of the soil samples collected from active-landslide sites and the existing database of landslide events. Three-dimensional hillside buildings are analysed for uphill-side landslide scenarios by performing force-controlled nonlinear static analyses. Further, a suite of earthquake ground motions is scaled to a predefined intensity level and nonlinear time history analyses are then performed to obtain the damaged state of the buildings prior to assessing the landslide response. It is observed that the earthquake loading history and its direction of excitation significantly affect the response of hillside buildings under landslide following earthquake. Further, it is also observed that the step-back building is more vulnerable to landslide damage as compared to its split foundation counterpart for a given uphill-side landslide scenario.","PeriodicalId":54570,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Structures and Buildings","volume":"13 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89773844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}