FULL AND PERFORATED METAL PLATE SHEAR WALLS AS BRACING SYSTEMS FOR SEISMIC UPGRADING OF EXISTING RC BUILDINGS

Metal Plate Shear Walls (MPSWs) represent an effective, practical and economical system for the seismic protection of existing RC framed buildings. They consist of one or more metallic thin plates, bolted or welded to a stiff steel frame, which are installed in the bays of RC framed structures. A case study of an existing RC residential 5-storey building, designed between the ‘60s and ‘70s of the last century and retrofitted with MPSWs, has been examined in this paper. The retrofitting design of the existing structure has been carried out by using four different MPSWs, namely three common full panels made of steel, low yield steel and aluminium and one innovative perforated steel plates. Finally, the used retrofitting solutions have been compared each to other in terms of performance and economic parameters, allowing to select the best intervention

Robustness of the Vesuvian roofs under the combined overload and high temperatures due to air falls

During an explosive eruption, a construction is hit by several actions, always associated to elevated temperatures, causing fires, possible explosions and reduction of the mechanical properties of the structural materials. In this paper, the attention is focused on the analysis of a specific volcanic event, the so-called air fall deposits, generally falling from the eruptive column due to gravity. In particular the robustness against the air fall deposit of the most common roofing structures, typically made of timber, steel and reinforced concrete, in the Vesuvian areais evaluated. Consequently, some protection systems for mitigating the effects of the combination of overloading and high temperaturesare identified

ISAB-2010 Foreword

AbstractArchimedes Bridge (AB) i.e. submerged floating tunnel (SFT), is a kind of floating transportation passage which is submerged underwater to bridge water banks. As an innovative transportation technology, AB will become attractive in competing with traditional bridges and tunnels due to its economical and environmental advantages. However at the present time, there is still not an actual AB being built in the world.The concept of AB was proposed for more than a century, and the researches and conceptual designs of AB with respect to several strait and lake areas were sporadically reported in the second half of past century. Due to scientific, technological and/or administrative uncertainties, such design projects were ceased or postponed.In the promotion towards the realization of AB in the world, scientifically and technically, there are two essential aspects should be implemented. One is the performance of numerical simulations and experimental investigations in laboratory, which will provide useful premise for the design and the preparation of construction. Another is to build a full-scale AB prototype to show its feasibility for the world.The progresses in such two aspects are deserved to be exchanged and disseminated world wide, such that the First International Symposium on Archimedes Bridge (ISAB-2010) was initiated to be held in Qiandao Lake, China during October 17-20, 2010. The location selection for the Symposium is due to the fact that the first Archimedes Bridge Prototype has been designed to be built in Qiandao Lake area. The initiation process of ISAB-2010 may be described somehow in detail.On December 6, 2004, an agreement was signed between Institute of Mechanics, Chinese Academy of Sciences (IMECH) and Ponte di Archimede International S.p.A, Italy (PDA) to establish a Sino — Italian Joint Laboratory of Archimedes Bridge (SIJLAB) with the research teams from IMECH in Beijing and from "Federico II" University in Naples and Polytechnic of Milan. The symbolic output of this cooperation was the completion of the structure design of Archimedes Bridge Prototype (ABP) in Qiandao Lake, which was presented in the two reports by the Chinese team [1] and by the Italian team [2].During the design cooperation and seminar exchanges between the two teams of SIJLAB, it was discussed and considered, from time to time, that to initiate and organize an international symposium on AB issues would be very helpful to promote the advances for the research and design of AB. This idea was reaffirmed by the representatives of the two teams in June last year in Trondheim at the 5th Symposium on Strait Crossings. We tentatively released this initiative at the SFT Workshop of the Symposium and received very positive response.After further consideration and relevant arrangement, the information of ISAB-2010 was formally announced on the website (www.ISAB2010.com), clearly expressing that the aim of ISAB-2010 is to provide a global forum for scientists, engineers and technicians around the world, who are involved or interested in researches and developments on the innovative technologies of AB, to share their research progresses and conceptual design advances, so that to discuss and improve the challenging issues of AB.We notice that, when people are talking about AB, the following questions are frequently asked. What is the history of AB concept and related researches? Why there is still not a real AB being built in the world? Whether an AB solution is competitive? What are the new scientific and/or technologic problems involved in AB research and design? What are the essential factors dominating the stability and reliability of AB?....We are confident that the above questions will be answered, to some extent, from the presentations of ISAB-2010 and from the proceedings of ISAB-2010 as this issue of Procedia Engineering.Finally, we would like to express our sincere appreciation to President Yongxiang Lu (Chinese Academy of Sciences) for his insightful idea of selecting Qiandao Lake as the location of AB and his great promotion towards the ABP project. We are also very grateful to President Elio Matacena (Ponte di Archimede International S.p.A, Italy) for his persistent stimulation towards the ABP project

Analysis of Fluid-structure Interaction for a Submerged Floating Tunnel

Abstract The behavior of a submerged floating tunnel (SFT) exposed to a water current of variable velocity is investigated through complex numerical analyses based on the Computational Fluid Dynamics (CFD) and the Finite Element Method (FEM) implemented in the ABAQUS code. An accurate modelling of turbulent phenomena is made, based on both Implicit Large Eddy Simulation and the RANS-based Spalart-Allmaras model, followed by a co-simulation procedure in which the fluid dynamics and the structural analysis are carried out separately and interfaced with each other. Circular and elliptical cross sections are considered, each of them fitted for combined railway and motorway services. The analysis is carried out in both static and dynamic way, by varying the current velocity with a given value of the residual buoyancy of the tunnel. The results emphasize the effect of the main parameters investigated, evidencing the great potentials of the adopted calculation tool for carrying out further investigations aimed at achieving useful elements for the design and optimization of the SFT

Analysis of rectangular‐shaped collar connectors for composite timber‐steel‐concrete floors: Push‐out tests

The paper deals with the experimental analysis of an innovative connection system for composite timber‐steel‐concrete floors. The connection device consists of a collar composed by two or more parts, astride the timber beam, bolted together at adjacent wings. A rubber layer is interposed at the collar‐beam interface. The slipping action transmission is guaranteed by the superior wings of the collar or by a steel stud, purposely welded to the collar in the upper part, which are immersed in the concrete cast. In this paper push‐out monotonic tests on several rectangular‐shaped configurations of the connection system are presented, being part of a more comprehensive experimental campaign, aimed at the system performance evaluation and optimization. First, the preliminary numerical analyses, meant to define both the best geometrical characteristics of the specimens and the configuration of the testing apparatus, are illustrated. Then the push‐out tests, considering subsequent improvements of the connection system are detailed. The connection behaviour is discussed in terms of force‐slip relationship. Santrauka Pateikiami inovatyvios jungčių sistemos, taikomos medžio, plieno ir betono perdangose, eksperimentiniai tyrimai. Jungtį sudaro apkaba, sudaryta iš dviejų ar daugiau dalių. Ši jungtis apjuosia medinę siją, o atskiros jos dalys tarpusavyje sujungiamos varžtais. Tarp apkabos ir medžio paviršių dedamas gumos intarpas. Šlyties įtempius, atsirandančius medinės sijos ir gelžbetoninės perdangos sąlyčio zonoje, perima sparninės jungės arba prie apkabos viršutinės dalies privirintas plieno strypas. Straipsnyje pateikiami naujos jungčių sistemos kai kurių stačiakampio formos apkabų eksperimentinių išstūmimo bandymų rezultatai. Pateikti tyrimai yra dalis plačios eksperimentinių tyrimų programos, kuria siekiama atlikti naujos sistemos elgsenos analizę ir optimizavimą. Pirmiausia pateikiami preliminarūs skaitinės analizės rezultatai. Ši analizė skirta optimaliausioms geometrinėms charakteristikoms bei formoms parinkti. Paskui, priėmus atitinkamus geometrinių matmenų ir formų patikslinimus, atlikti išstūmimo eksperimentiniai tyrimai. Jungčių elgsena nagrinėta analizuojant jėgos ir praslydimo priklausomybes. First Published Online: 14 Oct 2010 Reikšminiai žodžiai: kompozitinė medžio ir betono perdanga, apkabinė jungtis, išstūmimo eksperimentiniai tyrimai