Current Issue : January - March Volume : 2019 Issue Number : 1 Articles : 5 Articles
Curved surface sliders are being used more and more in the seismic isolation of buildings. *ey are preferred not only because of\ntheir lower cost with respect to elastomeric isolators but also of their technical characteristics, such as the fact that the value of the\nperiod of vibration is independent of the mass and the automatic coincidence between the gravity mass center of the superstructure\nand the stiffness center of the isolation system. In this paper, these features are analysed with reference to simple\nstructures, pointing out the possibility of rotations of the superstructure and the loss of contact in some devices. Finally, the\nimportance of the static friction is also emphasized showing the experimental seismic response of an isolation system under a lowenergy\nearthquake. For all these reasons, the use of nonlinear analysis, revised and detailed in this paper, is advisable for the\nisolation system made of curved surface sliders....
Structural efficiency of tapered tall buildings has been well recognized, and many tall\nbuildings of tapered forms have been built throughout the world. Tall buildings are built with\nan enormous amount of building materials. As one of the most efficient structural forms for tall\nbuildings, the contribution of tapered forms to saving structural materials coming from our limited\nnatural resources could be significant. Structural design of tall buildings is generally governed by\nlateral stiffness rather than strength. This paper systematically studies the structural efficiency of\ntapered tall buildings in terms of lateral stiffness. Tall buildings of various heights and angles of taper\nare designed with different structural systems prevalently used for todayâ??s tall buildings, such as\ndiagrids, braced tubes, and core-outrigger systems. The heights of the studied buildings range from\n60 to 100 stories, and the corresponding height-to-width aspect ratios in their non-tapered prismatic\nforms range from 6.5 to 10.8. The angles of taper studied are 1, 2, and 3 degrees. Gross floor area\nof each building of the same story height is maintained to be the same regardless of the different\nangles of taper. Based on design studies, comparative evaluation of the various structural systems for\ntapered tall buildings is presented....
*is paper presents a study to simulate the performance of steel-plate composite bridge under various blasting loads. *e multi-\nEuler domain method based on the fully coupled Lagrange and Euler models is adopted for the structural analysis of explosion\nprocess with the commercial software Autodyn. Due to the difference of material characteristics and space distribution between\nthe concrete and steel part, the most adverse position is estimated to be above and below detonation. A remarkable difference\nbetween these two explosive denotations for steel-concrete composite bridge is noted, and the failure mode above denotation is the\ndamage of local concrete deck, with the compression mode near the denotation point showing a standard trigonometric curve.*e\nfailure mode below denotation includes damage of steel girders and concrete failure near junction....
To develop the cold-formed steel (CFS) building from low-rise to mid-rise, this paper\nproposes a new type of CFS composite shear wall building system. The continuous placed CFS\nconcrete-filled tube (CFRST) column is used as the end stud, and the CFS-ALC wall casing concrete\ncomposite floor is used as the floor system. In order to predict the seismic behavior of this new\nstructural system, a simplified analytical model is proposed in this paper, which includes the\nfollowing. (1) A build-up section with â??new materialâ? is used to model the CFS tube and infilled\nconcrete of CFRST columns; the section parameters are determined by the equivalent stiffness\nprinciple, and the â??new materialâ? is modeled by an elastic-perfect plastic model. (2) Two crossed\nnonlinear springs with hysteretic parameters are used to model a composite CFS shear wall;\nthe Pinching04 material is used to input the hysteretic parameters for these springs, and two crossed\nrigid trusses are used to model the CFS beams. (3) A linear spring is used to model the uplift\nbehavior of a hold-down connection, and the contribution of these connections for CFRST columns\nare considered and individually modeled. (4) The rigid diaphragm is used to model the composite\nfloor system, and it is demonstrated by example analyses. Finally, a shaking table test is conducted on\na five-story 1:2-scaled CFS composite shear wall building to valid the simplified model. The results\nare as follows. The errors on peak drift of the first story, the energy dissipation of the first story,\nthe peak drift of the roof story, and the energy dissipation of the whole structureâ??s displacement\ntimeâ??history curves between the test and simplified models are about 10%, and the largest one of\nthese errors is 20.8%. Both the timeâ??history drift curves and cumulative energy curves obtained\nfrom the simplified model accurately track the deformation and energy dissipation processes of the\ntest model. Such comparisons demonstrate the accuracy and applicability of the simplified model,\nand the proposed simplified model would provide the basis for the theoretical analysis and seismic\ndesign of CFS composite shear wall systems....
China is a country with many earthquakes. Seismic safety monitoring and building\nearthquake-proofing technique are important means to protect the safety of\npeopleâ??s property in China. However, up to now, Chinaâ??s seismic reinforcement\nand identification technology is still not mature enough. In particular, the 2008\nWenchuan earthquake caused great loss of life and safety to the Chinese people.\nThis paper, takes seismic identification and reinforcement technology of building\nstructures as the research object and summarizes the main methods of building\nstructure seismic resistance in China. This paper is based on an in-depth analysis\nof the main seismic reinforcement and identification techniques in China, deeply\nanalyzes the crux of anti-seismic and reinforcement of building structure combining\nwith the current building seismic reinforcement typical cases, and puts\nforward some reasonable suggestions and improvement methods for the future\ndevelopment of building seismic identification and reinforcement design....
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