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Seismic performance of horizontal swivel system of asymmetric continuous girder bridge

Wang Jiawei, Gao Hongshuai, Zhang Kexin, Mo Zongyun, Wang Hongchung

Archives of Civil Engineering

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2023

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Vol. 69, nr 1

287--306

EN

The bridge horizontal swivel system generally adopts a symmetrical structure and uses a spherical hinge structure that can adjust the rotation to complete rotation construction. Because of the complexity of railway lines under bridges, some asymmetrical horizontal swivel systems have been increasingly applied in practical engineering in recent years. This system is more suitable for areas with complex railway lines, reduces the bridge span, and provides better economic benefits. However, it is also extremely unstable. In addition, instability can easily occur under dynamic loads, such as earthquake action and pulsating wind effects. Therefore, it is necessary to study their mechanical behavior. Based on the horizontal swivel system of an 11,000-ton asymmetric continuous girder bridge, the dynamic response of the horizontal swivel system to seismic action was studied using the finite element simulation analysis method. Furthermore, using the Peer database, seismic waves that meet the calculation requirements are screened for time-history analysis and compared to the response spectrum method. The mechanical properties of the structural system during and after rotation were obtained through calculations. During rotation, the seismic response of the structure is greater. To reduce the calculation time cost, an optimization algorithm based on the mode shape superposition method is proposed. The calculation result is 87% that of the time-history analysis, indicating a relatively high calculation accuracy.

2

Seismic performance of concrete columns confined by high‑strength stirrups

Hou Chongchi, Zheng Wenzhong, Liu Pengfei, Wang Qinghe, Qi ShaoBo

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 2

art. no. e69, 2023

EN

The concrete columns confined by high-strength stirrups exhibited higher bearing capacity and better deformation ability. Based on the test results of concrete columns confined by high-strength stirrups under lateral cyclic loading, it is found that stirrup yield strength could not be used directly in calculating bearing capacity, because the high-strength stirrup could not yield at the peak point. Moreover, according to the seismic performance of a total of 49 sets of confined concrete columns from this paper and other 5 research papers, an easy-to-use model of skeleton curve is proposed by using a set of empirical equations to calculate the characteristic points of skeleton curve. Furthermore, based on the proposed model of skeleton curve, hysteretic rules are developed for the unloading and reloading stages by providing calculating formula of unloading stiffness and ignoring the effect of strength degradation. Finally, the proposed model of skeleton curve and hysteretic rules are verified and evaluated by comparing the calculated curves and experimental curves.

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A review of the seismic performance behaviour of hybrid precast beam-to-column connections

Ghayeb Haider Hamad, Sulong N. H. Ramli, Razak Hashim Abdul, Mo Kim Hung, Ismail Zubaidah, Hashim Huzaifa, Gordan Meisam

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 1

art. no. e35, 2023

EN

In order to withstand challenges such as earthquakes, it is important to appropriately design the beam-to-column connection of precast structures. Numerous precast connections were designed to be used worldwide to attain satisfactory seismic performance. The failures observed for many beam-column connections were primarily due to the brittle behaviour of poor connection details between the precast concrete members. This review article examines past experimental studies which used hybrid precast connections comprised of three types: (1) dry and wet connections with steel sections (Type I), (2) composite concrete (Type II), and (3) composite concrete and steel sections (Type III). The seismic performance behaviour of these connection types was evaluated and compared with that of the monolithic connections. The analysis showed that both the dry semi-rigid and rigid connections Type I can be implemented in the seismic zones. In addition, most of the wet connections Type I, Type II, and Type III can simulate the behaviour of monolithic rigid connections. Therefore, the wet connections Type I, Type II, and Type III can withstand high seismic excitations. Overall, the performance of hybrid dry connection Type I can be improved by using strengthening technique methods in the connection to maintain the continuity of the PC beam. Moreover, the use of composite materials with and without the steel sections as connector elements in the connection (Type II and Type III) can be a feasible method to simulate the seismic performance of monolithic connections.

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Preliminary evaluation of seismic performance of engineering structures with perform 3D

Li Dongmei

Archives of Civil Engineering

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2019

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Vol. 65, nr 4

189--201

EN

This study analyzed the role of PERFORM 3D in the preliminary evaluation of seismic performance of engineering structures. Firstly, PERFORM 3D was briefly introduced, and its material constitutive model and basic model were analyzed. Then, taking a high-rise building project in Yulin, Shaanxi, China, as an example, PERFORM 3D was used to evaluate its seismic performance. After establishing the engineering model, five seismic waves were selected for simulation. The results showed that the maximum values of X-axis inter-story displacement angle and Y-axis displacement angle were 1/500 and 1/360 respectively, which were far less than the standard limit; the overall energy dissipation was good, the damping was small, the overall deformation was good, and the seismic performance was also good. In conclusion, PERFORM 3D has a good performance in the preliminary evaluation of seismic performance of engineering, and it is worth further promotion and application.