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Single-layer reticulated domes with high capacity and attractive shapes are widely used in many modern facilities, ranging from industrial architecture to large-scale public buildings, including railway stations, sports gymnasiums and exhibition halls. In order to understand the seismic performance of single-layer reticulated dome subjected to three-dimensional seismic motion, a shaking table test on this type of structure was conducted, and the experiment was also simulated using FEA software ABAQUS considering the material damage accumulation. And then, an innovative three-dimensional isolation bearing with the corresponding mechanical model was applied to reduce the dynamic responses of the structure. Furthermore, the seismic performance of single-layer reticulated dome with the isolated bearing was investigated through shaking table test and numerical simulation. The results show that FEA software ABAQUS with a user-defined subroutine (UMAT) to consider material damage accumulation can accurately simulates the structural dynamic behaviour before and after the application of the isolated bearing. Therefore, numerical analysis will be used in the different types of large-span space structure in the further study. At the same time, the design and engineering practice of the three-dimensional isolation bearing is mainly realized by numerical analysis, which is of great support significance for the quantitative research and engineering practice of the isolated large-span space structure. This can also make this new isolation technology quickly popularized, and also has an important role in promoting the subsequent revision of seismic isolation code for large-span space structure. [ABSTRACT FROM AUTHOR]

With the rapid development of the large-span space structure, it has been widely used in the public buildings such as gymnasiums, exhibition hall, airplane terminal, etc. in China recently. The large-span latticed shell buildings are usually the landmark buildings in a city, so its collapse will cause serious economic and personal loss, which will affect national security and social stability. The shaking table test was conducted on the single layered cylinder shell model in this paper, and the dynamic amplification effects of the lower support frame and the dynamic responses of the whole model were obtained under different seismic motion inputs. The seismic performance of the single layered cylinder shell was evaluated under different ground motion inputs and input principal directions, and the collapse mode was obtained. The results show that the input principal direction has great effect on the dynamic characteristics of the model, and the dynamic amplification effect of the lower support frame increases with the magnitude increase of the ground motion inputs. There is no obvious impact effect and the dynamic strain responses behave elastic during the collapse process, and the whole shell collapse because of local instability. It concludes that the single layered cylinder shell has the risk of progressive collapse under the seismic motions, so the collapse resistance of single layered cylinder shell should be enhanced or it should be optimum designed to prevent the progressive collapse. This experimental study will provide references to the seismic design and engineering practices. [ABSTRACT FROM AUTHOR]

Space double-layer cylindrical reticulated shells (SDLCRS) have undergone rapid development in the four three decades. Significantly different from conventional multistory high-rise structures, such structures are very sensitive to vertical actions. As a result, conventional seismic isolation techniques that aim to reduce horizontal seismic actions are notably insufficient for this kind of structure. In this study, a new three-dimensional seismic isolation bearing was developed that can simultaneously reduce the horizontal and vertical seismic responses of an SDLCRS. To examine the actual seismic isolation effectiveness of the three-dimensional seismic isolation bearing and provide important theoretical, technical and experimental support for practical engineering applications, comparative shaking table tests were performed on isolated and non-isolated SDLCRSs with lower supporting structures. The 2013 Lsf ground motion record during Lushan earthquake and the 1954 Taft ground motion record were selected as seismic inputs. The dynamic responses including acceleration, displacement and strain of the SDLCRS under the input ground motions with different amplitudes were obtained using the shaking table tests. In addition, the seismic damage of the isolated and non-isolated structures was examined to determine the acceleration amplification effect of the structures. The effectiveness in acceleration and strain responses demonstrated that the three-dimensional seismic isolation bearing was very useful for horizontal and vertical seismic isolation. Moreover, the maximum displacement responses of the bearing were less than half of the respective design displacements, suggesting that the bearing still had considerable reserve bearing capacity and could significantly improve the safety of an SDLCRS under seismic loads. The bearing developed in this study not only has excellent seismic isolation performance and post earthquake restoration capability but can also be easily installed and maintained. Thus, this bearing holds great promise for engineering applications and is suitable for SDLCRS that require both horizontal and vertical seismic isolation. • A new three-dimensional seismic isolation bearing was developed to reduce the seismic responses of Space double-layer cylindrical reticulated shell. • To examine the seismic isolation effectiveness of the isolation bearing, shaking table tests were performed on isolated and non-isolated model structures. • The seismic damage of the isolated and non-isolated structures was examined to determine the acceleration amplification effect of the structures. • The results demonstrated that the three-dimensional seismic isolation bearing was very useful for horizontal and vertical seismic isolation. • The bearing developed in this study not only has excellent seismic isolation performance but can also be easily installed and maintained. [ABSTRACT FROM AUTHOR]

• This paper investigates the characteristics and rules of the seismic damage of large span spatial structure during the Lushan earthquake and discusses the possible causes of such damage. • A shaking table test was conducted with a down-scaled model of a double-layer cylindrical shell structure to obtain the dynamic response of a structure by reasonably arranging the acceleration, velocity and displacement measuring points. The failure pattern and progressive collapse process of the structure under a severe earthquake were investigated. The buckling of members increased with the increment of ground motion, although this effect was not considered in the present code for seismic design for double-layer shell spatial structures. • The seismic damage in the test was mainly represented by overall buckling of the upper chord, web member and lower chord, which is the direct reason for the structural collapse during a severe earthquake. • The test results indicated that the change in surface curvature of the structure resulting from deformation during a severe earthquake transformed gravitational potential energy into kinetic energy and caused chord members to impact and fracture, thereby inducing progressive collapse of the structure. Large span spatial steel structures, such as gymnasiums, exhibition halls, airport terminals, or railway hubs, have developed rapidly over the last four decades. However, the mechanical properties of these structures under complex loads, particularly their seismic performance under severe earthquakes, are not sufficiently understood. During the 2013 M7.0 Lushan earthquake in China, some of the large span spatial structures suffered damage of varying degrees, which necessitates a review of previous seismic designs and theories. This paper investigates the characteristics and rules of the seismic damage of large span spatial structure during the Lushan earthquake and discusses the possible causes of such damage. A shaking table test was conducted with a down-scaled model of a double-layer cylindrical shell structure to obtain the dynamic response of a structure by reasonably arranging the acceleration, velocity and displacement measuring points. The failure pattern and progressive collapse process of the structure under a severe earthquake were investigated. The buckling of members increased with the increment of ground motion, although this effect was not considered in the present code for seismic design for double-layer shell spatial structures. The seismic damage in the test was mainly represented by overall buckling of the upper chord, web member and lower chord, which is the direct reason for the structural collapse during a severe earthquake. The test results indicated that the change in surface curvature of the structure resulting from deformation during a severe earthquake transformed gravitational potential energy into kinetic energy and caused chord members to impact and fracture, thereby inducing progressive collapse of the structure. The findings of this paper provide a basis for the seismic theory and design of large span spatial steel structures. The buckling effect of double-layer cylindrical shell structures, the dynamic amplification effect of the support structures, and the transformation of gravitational potential energy to kinetic energy in particular would be of interest to researchers and designers. [ABSTRACT FROM AUTHOR]

This study investigated the dynamic characteristics and seismic isolation performance of a single-layer cylindrical grid shell structure with lower support structures and different seismic isolation schemes, which encompass the installation of layered rubber bearings and new three-dimensional isolation bearings. Seven reduced-scale models of the structure were tested on a shaking table, with acceleration, strain, and displacement sensors positioned in typical locations. The results showed that the seismic response of the upper cylindrical grid shell structure was amplified by the lower support structure, which indicates that separate seismic designs for both the upper structure and lower support structure are unsafe. The use of layered rubber bearings at the foundation effectively reduced horizontal seismic response but amplified vertical seismic response. To address this issue, the new three-dimensional isolation bearing was proposed, which showed better overall seismic isolation performance compared to the rubber bearings. Additionally, a new seismic isolation scheme was proposed, using a combination of three-dimensional isolation bearings at both the foundation and column tops. This scheme showed superior seismic isolation efficiency compared to other schemes and can reduce the volume and installation difficulty of the three-dimensional isolation bearing. Considering the functional requirements, cost, and technical difficulty is crucial when selecting suitable seismic isolation measures since different schemes have their advantages and disadvantages and perform differently under various seismic conditions. • Studied seismic behavior of cylindrical grid shells with varied isolation methods. • Confirmed lower support enhances the upper structure's seismic response. • Rubber bearings mitigate horizontal, and amplify vertical seismic response. • Optimal isolation was achieved using new 3D bearings at the foundation and column tops. [ABSTRACT FROM AUTHOR]