The substation is the core link in the transmission and distribution of electricity. Post-electrical equipment holds an important position in substations. They are not only numerous but also diverse, and are very likely to be damage in earthquakes. This paper takes the 500 kV voltage transformer as the research object, installs a new type of steel wire rope seismic isolation bearing on it, and compares and analyzes the response characteristics of the prototype structure and the seismic isolation structure under seismic action through the seismic simulation shaker test. The test results show that the fundamental frequency of the isolation structure has been significantly reduced compared with the prototype structure, confirming the effectiveness of the new wire rope seismic isolation support in reducing the seismic response of post-electrical equipment. Meanwhile, the seismic isolation structure shows high isolation efficiency in reducing acceleration and stress response, but the isolation effect for displacement response is relatively limited. Under strong seismic effects, the seismic isolation structure can effectively reduce the acceleration and stress response of the equipment, which reduces the risk of breakage of porcelain insulators of transformers due to vibration. At the same time, the seismic isolation bearings will not have significantly reduced the top displacement response of the equipment. Therefore, in the subsequent improvement of the new wire rope seismic isolation support, it is necessary to comprehensively consider the various responses caused by seismic forces to ensure the overall safety of the equipment.

The isolation structure is equipped with isolation devices to extend the natural vibration period and reduce the seismic response. However, improper construction causes the infill wall to be built around the isolation device, which restricted the free movement of the superstructure, thus affecting the actual isolation performance of the structure. In order to quantify the impact of the above unfavorable factors on the seismic isolation performance of the structure, this paper takes a certain reinforced concrete(RC) frame as the research object, uses a method of combining in-situ testing and numerical simulation, and compares and analyzes in the OpenSees considering whether the constraint effect of the infill wall is taken into account. Seismic response of isolation structures under different types of earthquake motions. The research results show that compared with unconstrained seismic isolation structure, the maximum acceleration of the upper floors, the maximum inter-story drift and the maximum base shear force of structures with seismic isolation layers constrained by peripheral infill walls increase by 20.4%, 38.7%, 35.7% under frequent earthquakes. The displacement of the isolation layer is reduced by 79.4%. Under the action of seismic precautionary earthquakes, they increase by 21.6%, 59.8%, 86.5%, respectively, and the displacement of the isolation layer is reduced by 37.8%. Under the action of rare earthquakes they increased by 17.7%, 19.4%, and 14.9% respectively, and the displacement of the isolation layer decreased by 10.3%. As the peak acceleration of the input ground motion increases, the lead rubber bearing will play a greater role only after the infill wall is damaged. Under rarely occurred earthquake, the seismic isolation layer breaks through the constraints of the surrounding filling walls and can basically achieve the seismic isolation effect.

In view of the special performance requirements of the rocking wall, the rocking wall structure is often trapped in the dilemma of construction technology, rocking range and cost control in engineering application. Based on the concepts of economic benefits, convenient construction, and easy replacement after earthquake, an energy-consuming connection device between the frame and the rocking wall was developed. Additionally, a hinge support with controllable swing of the rocking wall was also designed for the test models. Thus, a new type of reinforced concrete (RC) frame-rocking wall damping structure is proposed by loveraging the structural advantages of the rocking wall structures and the principle of passive control technology. Then, 1/10 scale shaking table tests of six-story RC frame structure and RC frame-rocking damping wall were conducted to verify the effectiveness of the structure. The dynamic characteristics, acceleration response, and displacement response of the test models under different earthquakes were studied by shaking table tests. The failure mode and seismic performance of the test models were also described. The results show that the rocking wall damping system can effectively consume seismic input energy and attenuate structural dynamic response, reducing the maximum peak acceleration and the maximum peak displacement of the structure by 36% and 20.15%, respectively. Moreover, the rocking wall damping structure can also effectively suppress the vibration of the main structure by using the principle of passive damping, improving the lateral deformation mode of the frame structure. Additionally the damage process of the structure is delayed, enhanced the overall seismic capacity of the structure.

In response to the current inability of the strong-motion observation network to provide seismic input records covering all areas of the epicenter vicinity, a technical framework for the rapid generation of kilometer-grid strong motion time histories has been established. Taking the M_S6.8 earthquake in Dingri, Xizang on January 7, 2025, as an example, the detailed processes of each technical procedure are described, and work on the inversion of the source rupture process, estimation of regional site conditions, and simulation of strong motion time histories has been carried out. The following results are obtained. The earthquake released a seismic moment of 4.7×10¹⁹ N•m, corresponding to a moment magnitude of 7.05. The fault slip is predominantly normal with a small amount of left-lateral strike-slip component, and the maximum slip displacement exceeded 3 meters. The rupture lasted for more than 20 seconds, mainly propagating in the northward direction, which may cause potential directivity effects. A V_S30 distribution map and engineering site classification map with a resolution of 30 arcseconds are provided, and the sites in the vicinity of epicenter area are mainly classified as ClassⅠand ClassⅡ, with V_S30 values ranging from 260 m/s to 510 m/s in the majority of the southeast area. Simulated three-component acceleration time histories for 14 996 virtual observation points in the near-field area (27°30′N~30°00′N、86°18′E~88°36′E) are provided, and the accuracy of the simulation results is verified by actual observation records. The maximum horizontal peak ground acceleration(PGA) can reach 1.0 g, and the 0.4 g and 0.2 g isolines approximately coincide with the IX and Ⅷ isoseismals, while the 0.10 g and 0.05 g isolines enclose areas slightly smaller than the Ⅶ and Ⅵ isoseismal zones. This research work and its results can provide reasonable seismic input for the damage identification, disaster evaluation, and resilience assessment of various disaster-bearing bodies in the epicentral area.

On January 7, 2025, an earthquake of magnitude M_S6.8 struck Dingri County, Xizang Autonomous Region. In this paper, the near-field seismic wave field and instrumental intensity field were simulated using the strong ground motion simulation and prediction cloud platform of the Institute of Engineering Mechanics, China Earthquake Administration (CEA), combined with the kinematic seismic source model, the regional public velocity model and the digital elevation model. The simulated and measured instrumental seismic intensities are comparable at the stations of the National Seismic Intensity Rapid Reporting and Early Warning Project. The simulated high intensity zones are mainly distributed around the place of the surface projection fault, and the simulated instrumental seismic intensity field is basically the same as the survey seismic intensity field. On the basis, the earthquake damage to typical buildings (mainly earth/stone and wood structures) and casualties was evaluated and the evaluation results were also comparable to the actual data.

Buildings are essential fundamental for maintaining the economic, cultural, social, and functional aspects of urban life and are the basis for ensuring urban seismic resilience. The seismic resilience of buildings not only depends on the seismic capacity of structural components but also on non-structural components and equipment. Currently, there are no established methods for enhancing the seismic resilience of existing buildings. This paper outlines the basic approach for enhancing the seismic resilience of existing buildings, proposing methods aimed at ensuring structural safety, meeting predefined functional requirements, and enabling rapid recovery. The paper establishes seismic resilience enhancement objectives for existing buildings, considering both the function and the remaining service life of the buildings, and a “five-step” approach to enhancing seismic resilience is also developed. Finally, a case study of a specific building’s seismic resilience enhancement is presented to preliminarily verify the rationality and feasibility of the proposed methods. This paper can provide practical insights for enhancing the seismic resilience of buildings, as well as individual infrastructure components such as bridges and tunnels.

The main task of the building structure array is to record the failure process of civil engineering structures in detail, and to provide structural response information for many related studies such as seismic design, seismic damage assessment, and earthquake safety alarm. However, due to the constraints of economic cost, field testing technology and data processing level, it is unrealistic to deploy sensor monitoring equipment on all floors of the entire structure, so how to obtain the most complete structural information with the least number of sensors is the purpose of optimizing the layout of structural array sensors. Considering the advantages and disadvantages of the effective independent method and the modal kinetic energy method, a unit stiffness energy-driving point retention method was proposed, considering the advantages and disadvantages of the effective independent method and the modal kinetic energy method. In this method, the unit stiffness modal energy is used as the information matrix, and the principle of effective independence method is used to screen the measurement points, so as to ensure that the high-energy measurement points maintain linear independence to the greatest extent. Finally, taking a steel frame as an example, the proposed method, the effective independence method, the modal kinetic energy method and the unit stiffness method are used to lay the sensors on the model respectively, and the modal assurance criterion and the Fisher information matrix criterion are used to evaluate the layout results of the four methods. The results show that, compared with the other three methods, the proposed method has the least number of sensors when the mode vectors are linearly independent, and the proposed method can obtain the most modal information with the same number of sensors.

Clutching inerter damper (CID) has been extensively studied in structural vibration control recently. Because the passive CID device does not take into account flywheel speed reset and cannot achieve an ideal piecewise model, its control performance is limited. Therefore, this study explores the semi-active implementation of the ideal CID model. This paper begins with a comparative study of the ideal and passive analytical models of CID, providing insight into the performance differences and limitations of the two models. Subsequently, an electromechanical clutching inerter damper (ECID) scheme is proposed, which includes energy harvesting and variable inertance. The implementation of the electrical inertance, flywheel speed reset, and energy recovery functions are also discussed, and an electromechanical hybrid simulation model of the ECID is established. This paper thoroughly examines the control and energy recovery performance of the ECID through theoretical and simulation analyses. It explores the effects of resistance and capacitance in the ECID circuit on system performance and demonstrates that the ECID has significant vibration control and energy recovery capabilities. This study presents a comprehensive scheme for the implementation of CID, variable inertance, and energy recovery, which has theoretical reference significance for the development of self-powered semi-active variable inertance devices.

Reducing the seismic acceleration response of nuclear containment and ensuring the safety of nuclear power equipment under strong earthquakes is of practical significance for improving the seismic toughness of nuclear containment. Tuned mass damper (TMD) can effectively reduce the wind vibration response, but it has the disadvantages of narrow frequency band and low damping efficiency for seismic response control. By combining TMD with inertial volume, a tuned mass damper inerter (TMDI) is proposed to reduce the seismic acceleration of nuclear containment. Based on the performance requirement design idea and H_∞ optimization criterion, an optimal parameter design method for TMDI was established. On this basis, a numerical simulation method is developed by using the substructure idea combined with ABAQUS and Matlab, and the finite element simulation of the seismic response of nuclear containment under TMDI control is realized. The validity of the theoretical analysis is verified by the TMDI seismic control example of a finite element model of a nuclear containment. The results show that the peak acceleration absorption rate of the top of the nuclear containment is 46.1% when TMDI is used, and the tuning mass required when TMDI reaches the same damping index is reduced by 28.2%.

In order to limit the excessive relative displacement between pier and beam, a latticed long-stroke restrainer(LLSR) based on shape memory alloy (SMA) bar is proposed on the basis of single long-stroke shape memory alloy restrainer (LSR). The device consists of SMA alloy bar with excellent superelasticity and re-centering performance, MC nylon, steel pipes and strips or plates. SMA bars can consume ground motion energy and provide re-centering capability. The MC nylon and steel pipe form an anti-buckling system to prevent the SMA bar from buckling under pressure. Firstly, the structure and working mechanism of single long-stroke shape memory alloy damper and lattice long-stroke shape memory alloy damper are described. Secondly, the tensile test of SMA bars under different heat treatment temperature was carried out to determine the SMA bar with the best superelasticity, which was then used as the inner core of the LSR. Then, the axial tension and compression experiment of a single LSR was conducted to further study its mechanical properties. Finally, based on the experimental data of the LSR and the finite element software of ABAQUS, the numerical analysis and parameter analysis of the LLSR were carried out, and the corresponding design method was proposed according to the results of numerical analysis and parameter analysis. The research shows that LLSR not only has stable energy dissipation capacity but also has good re-centering ability.