The urban lifeline engineering system, serving as a key infrastructure that ensures the daily lives of residents, the functional operation of the city, the healthy development of the economy, and the long-term stability of society, is the cornerstone of resilient city construction. Research on seismic resilience assessment methods for urban lifeline engineering systems has achieved certain progress both domestically and internationally. However, the seismic resilience design methods for urban lifeline engineering systems remain underdeveloped. This paper expounds on the concept of seismic resilience design for urban lifeline engineering systems and delineates the differences between seismic resilience design for urban lifeline engineering systems and traditional seismic design for individual urban lifeline facilities. The basic framework of seismic resilience design, characterized by the “two dimensions”, is put forward, which ensures the structural seismic safety of individual facilities through the structural safety design of individual facilities, and guarantees the post-earthquake functionality and rapid recovery of the engineering system through the resilience coordinated design among individual facilities. The basic requirements for seismic resilience design, characterized by the “three objectives”, are established, ensuring structural seismic safety of individual facilities, meeting predetermined functionality of individual facilities and the engineering system, and enabling rapid recovery of the engineering system. The key steps of seismic resilience design, characterized by the “four components” are proposed, which include determining the seismic resilience goals for the engineering system, structural safety design for individual facilities, post-earthquake functionality verification for the engineering system, and identification of technologies and strategies for the rapid recovery of the engineering system. A unified seismic resilience design approach for urban lifeline engineering systems is established. This paper takes a road transportation system as an example to conduct seismic resilience design. The preliminary results validated the rationality and feasibility of the proposed seismic resilience design approach. The design approach enables the transition of seismic design for urban lifeline engineering systems from structural seismic design, which ensures the structural seismic safety of individual facilities, to seismic resilience design, which ensures post-earthquake functionality and rapid recovery of the engineering system. The proposed approach can also provide a practical solution to improve their seismic resilience.

This paper proposes a nonlinear spring restraint structure to overcome the limitations of the static thrust test method in evaluating underground structure systems. Considering the difficulties of soil-structure interaction, high costs, and limited observability of test phenomena, the proposed approach integrates basic principle of the reaction displacement method for underground structures. It recognizes that the traditional elastic spring fails to capture soil state changes during loading, thus prompting the introduction of a more dynamic spring-structure system. It suggests using nonlinear springs instead of soils for analyzing seismic performance. Through Pushover analysis on a single-span underground structure model, the influence of factors such as the axial compression ratio and spring-structure interaction on mechanical performance is investigated. Comparing bending moment capacity curves of key sections shows that the static thrust overlay model for spring-underground structures is suitable for seismic analysis of underground structures. Up to an inter-story displacement angle of 1/200, both the linear and nonlinear spring models are highly accurate, but beyond this threshold, the nonlinear spring model is significantly superior. The simplified analysis method for seismic performance of nonlinear spring-underground structure systems provides insights into the complex force behaviors of underground structures.

Earthquake magnitude estimation is one of the important tasks in earthquake early warning. Accurate earthquake magnitude estimation is critical to quick judgment of earthquake influence areas and timely release of earthquake warning information. Existing methods usually extract the characteristic information based on the acceleration time history of a single station to estimate the magnitude, and then obtain the result by the multi-station averaging method. In this paper, an end-to-end magnitude estimation model (GAT_M) is constructed using a multi-input graph attention network algorithm. The time history of multi-station seismic acceleration within 3 s after the first P-wave is triggered is input into the GAT_M model. The multi-station seismic acceleration waveforms within 3 s after the first P-wave are used as the input of the GAT_M model. In this study, the strong earthquake data from of the K-NET strong earthquake observation network of Japan Institute of Disaster Prevention Science and Technology were used for model training and test experiments. Within 3 s after the first P-wave triggers, the mean error and standard deviation of magnitude estimation are -0.077 and 0.40 respectively, and R² is 0.72. The effects of magnitude, time window and number of stations on the performance of GAT_M model are also analyzed. Simultaneously, within 3 s after the initial P-wave triggers, the GAT_M model demonstrates a reduced magnitude estimation error compared to the traditional Pd method. In the case of complex sample data, the GAT_M model has a greater advantage and can be better applied to magnitude estimation.

Reinforced concrete (RC) columns are exposed to serious seismic disaster risks due to corrosion damage of the internal rebar during the service period caused by environmental corrosion, causing the seismic performance of RC columns to deteriorate and thus be exposed to severe seismic hazard risks. This paper reviews the existing research on the seismic properties of corroded RC columns from four aspects: test methods, degradation law, failure mode prediction and bearing capacity calculation. The corrosion and loading methods used in seismic tests of corroded RC columns are elaborated. The effects of corrosion degree and main design parameters on the deterioration of seismic performance indexes such as ductility, stiffness and energy dissipation capacity of corroded RC columns are statistically analyzed. Based on the seismic test dataset of 290 corroded RC columns, the accuracy of three parametric delineation methods including shear span ratio, ductility coefficient, and shear demand ratio and the extreme gradient boosting (XGBoost) machine learning algorithm for failure mode recognition of corroded RC columns is compared. The influence of the degree of corroded and main design parameters on the failure modes of corroded RC columns is revealed by shapley additive explanations (SHAP) method. The calculation method of residual flexural and shear strength of corroded RC columns are summarized and the prediction effect are discussed. The results show that there are differences in corrosion shape, corrosion rate and corrosion accuracy under different corrosion methods. The bidirectional quasi-static loading mechanism can reflect the degradation law of seismic performance of corroded RC columns better than unidirectional loading. With the increase of the corrosion rate of the rebar, the ductility, stiffness and energy dissipation capacity of RC columns deteriorate significantly. The machine learning model combined with SHAP method can effectively balance the accuracy and interpretability of the failure mode prediction of corroded RC columns. This kind of data-driven prediction method provides a new way to solve the performance evaluation problem of corroded RC columns. Corrosion of rebar will degrade the flexural and shear capacity of RC columns, and the accuracy of the calculation model for the capacity of corroded RC columns proposed at this stage still requires further improvement so as to provide a reasonable basis for assessment of corroded components.

Previous seismic damage investigations have shown that the seismic damage of engineering structures is closely related to the site seismic response. Therefore, studying the site seismic response has significant theoretical and practical value for the earthquake fortification of engineering structures. The geotechnical vertical array is an important platform for conducting site seismic response studies. As one of the main methods of obtaining strong ground motion records of the surface and underlying strata, it provides data support for the study of site seismic response. Based on the distribution of most of the existing geotechnical vertical arrays in the world, this paper introduces the basic information of the Garner Valley downhole array and the Treasure Island geotechnical array in the United States, the Port Island downhole array in Japan and the seismic monitoring array of site and structure of the China Institute of Disaster Prevention in detail from four aspects: geographical location, soil layer lithology, instrument layout, and velocity structure. Combined with a large number of relevant literatures, this paper summarizes the research progress on soil nonlinear dynamic characteristics, site amplification effect, and seismic response analysis methods of soil layers utilizing geotechnical vertical array. It looks forward to the problems that urgently need to be improved in the follow-up research, which has a certain reference value for the in-depth study of the dynamic response mechanism of soil at different depths and the site seismic response with deep soil layers.

To study the mechanical behavior of panel zone of complex joints between concrete filled steel tubular (CFST) column and steel truss beam, this paper generates a three-dimensional model based on experimental results using ABAQUS and validates the validity of the model. Subsequently, several sets of models of “strong member and weak joint” models are designed on the basis of the test specimen through structural measures. The influence of the steel truss beam inclination angle, the axial pressure ratio of CFST column and the width-to-thickness ratio of steel tube is studied. The results indicate that the failure mode of panel zone in CFST column-steel truss complex joint is the failure of panel zone within the range of bottom chord, accompanied by the failure of truss girder end. The influence of steel truss beam inclination angle on mechanical behavior and failure mode of panel zone is small. When the axial compression ratio is large, the shear capacity and ductility coefficient of the panel zone decrease obviously. Therefore, it is suggested that axial compression ratio of CFST column should not exceed 0.3. Width-to-thickness ratio of steel tube is a sensitive parameter, and the shear capacity, initial stiffness, and ductility coefficient of panel zone change significantly with the decrease of width-to-thickness ratio of steel tube.

To introduce the quasi-isolation concept in the transverse earthquake-resisting system of small-to-medium-span girder bridges, first the basic connotation of the quasi-isolation concept was elaborated based on the typical seismic damage statistical characteristics, and the performance roles of the critical elements (i.e. bearing, retainer and pier) were defined in the bridge earthquake-resisting system. Then, nonlinear analytical models were established for the bearing-retainer-pier systems considering the parameters of pier height and retainer capacity. Finally, the fragility analysis method based on the Copula functions was applied to investigating the coupling characteristics of the damage states of bearing, retainer and pier under earthquake actions, and the reasonable design capacity of retainer was explored according to the system-level deterministic fragility curves to satisfy the requirements of the quasi-isolation concept. The results showed that significant coupling relationships exist among the bearing, retainer and pier under seismic actions. The capacity of retainer has a notable impact on the damage states of bearing and pier. When the retainer capacity increases from 0 to 30% of the superstructural dead load reaction force, the damage probability of bearing decreases continuously, and a maximum decrease of 27.2% can be achieved at the complete damage state, while the damage probability of pier increases steadily with the maximum increase of 61. 6% at the complete damage state. The damage sequence gradually changes from the retainer, bearing, pier to the pier, bearing and then the retainer. When the retainer capacity is designed as 15%~20% of the superstructural dead load reaction force, the bearing sliding isolation and the pier plastic energy dissipation can be fully mobilized, and the severe damage probability of the bearing-retainer-pier systems under the seismic actions is the lowest and reduced by 16.3% when compared to that of the case without retainers.

In this paper, a kind of embedded bolt connector was proposed. The utilization of embedded steel blocks and bolt taper sleeves can reduce the damage to concrete and steel beams under load, and enable the removal and replacement of the composite beam. Eight groups of specimens were designed and manufactured. After the push-out test, the specimens were removed and reassembled. Subsequently, a reloading test was conducted and the demountable ability were analyzed. The influence of bolt diameter, bolt strength, T-shaped steel block and external diameter of the embedded steel block were discussed. The results showed that when the specimen was damaged, the bolt was cut or the concrete was crushed. Eight groups of specimens could be quickly disassembled after loading. The dismantled steel beam and T-shaped steel block could be reused for many times. After loading, the concrete slab in undamaged and slightly damaged state could be reused for more than twice, and the shear performance of the specimen remained basically unchanged. The concrete slab in a damaged condition can be reused once, but its shear resistance will be reduced. The concrete slab in a severely damaged condition is not to be reused. In addition, the embedded bolt connector has good anti-lift performance. With an increase of bolt diameter or strength, the bearing capacity of specimen and the damage of concrete slab increased. With an increase in the outer diameter of the embedded rigid block, the bearing capacity of the specimen remained unchanged, while the damage to the concrete slab decreased. The presence or absence of T-shaped rigid block had little impact on the bearing capacity of the specimen, but could enhance the demountable performance. Finally, the local damage coefficient η of concrete slab was proposed as the control index for demountable performance, and when η is about 0.5, it is in a good demountable state.

Due to the influence of topography and traffic routes, small radius curved bridges with eccentrically support piers and variable pier heights are widely used. Due to the irregularity of the bridge caused by the difference in pier heights and the eccentric supports, a complex stress form of pressure-bending-shearing-torsion coupling in the eccentrically support pier will occur. Taking an interchange ramp bridge as the engineering background, a centralized hinge-fiber model based on nonlinear finite element software was constructed. The seismic vulnerability of eccentrically compressed piers in two models was compared by adopting the incremental dynamic analysis method. These two models include a model with the concave-type variable height piers (the CTVHP curved bridge) and a model with gradient variable height piers (the GVHP curved bridge). The results show that: in the small radius bridge with eccentrically support pier and variable pier heights, the probability of torsional damage of the intermediate pier is higher. When the pier torsional damage occurs, the exceeding probability of each pier damage level in the CTVHP curved bridge is greater than that in the GVHP curved bridge, which will lead to more serious torsional damage. Therefore the arrangement of the CTVHP curved bridge should be avoided in seismic design, at the same time, the seismic capacity of the intermediate pier should be enhanced. The research results of this paper can provide a basis for similar bridges.

Based on the database of the Pacific Earthquake Engineering Research Center, the collected seismic records were classified according to the fault distance of the seismic stations, and the amplitude, spectrum and time characteristics of the ground motions under different site conditions were studied and quantitatively analyzed. Taking the Huangdeng gravity dam as the research object, based on the three response quantities of downstream displacement at the upstream dam face, principal tensile stress at the upstream dam face and principal compressive stress at the downstream dam face, the influence of near-fault earthquake pulse characteristics on seismic response of gravity dams was investigated. The results show that the relative displacement of the toe of the top dam of Huangdeng gravity dam under pulse earthquake is 44% larger than that under non-pulse earthquake. The principal tensile stress at the dam heel is 30% larger than that of the non-pulse type. The principal compressive stress at the toe of the dam is 31% greater than the response value of non-pulsed earthquake. The impact of pulse earthquakes on the structure is not negligible compared with non-pulsed earthquakes, and the response values of the structure were significantly larger. Therefore, it is necessary to consider the impulsive action of near-fault earthquakes in seismic fortification.

The fixed connection between the piers and the superstructure of rigid-frame bridges with high piers exhibits limitations in seismic design. Cracking of the cross-section and prestressing tendon stress loss can be found in the main girder subjected to seismic loads. The inertialr system ( i. e. tuned mass-damper-inerter, TMDI) contains an inertial container and a traditional tuned mass damper (TMD). It is a new method for structural seismic control in recent years. This study focuses a high-pier, long-span continuous rigid-frame bridge, considering the construction process and combining Midas Civil and the OpenSees to establish a nonlinear seismic response numerical model. Using 10 near-fault pulse-like ground motion records as input, this study investigates the seismic control behavior of a distributed configuration of multiple TMDIs. The results show that when the ground motion excites the bridge along the longitudinal direction, TMDIs can effectively prevent the cracking of the top and bottom slabs of the main girder, although the internal forces of the web of the main girder increase slightly. When the ground motion excites the bridge along the transverse direction, TMDIs significantly reduce the internal forces on the web of the main span. When ground motions are input in both horizontal directions, TMDIs can effectively mitigate the stress on the top slab, bottom slab, and web of the main span. Regarding the pier response, the average seismic reduction proportions of the maximum displacement at the pier top are 52% in the longitudinal direction and 21% in the transverse direction, respectively. The seismic reduction proportions of the maximum bending moment in the longitudinal direction is 31%. Although TMDIs increase the bottom bending moment of the pier by approximately 10% in the transverse direction, they effectively control the residual displacement of the bridge pier.

Vertical ground motion is a serious threat to bridges and other structures in high intensity areas, and the relationship with horizontal ground motion is complicated. However, the current Code for seismic design of railway engineering(GB 50111—2006) (2009 edition) does not make special provisions for the vertical design response spectra. Some other specifications only stipulate that the vertical response spectra should be taken as a fixed ratio of the horizontal spectra, which may make the estimation of vertical ground motion unreliable. In view of the urgent need to revise the current seismic design code for railway engineering in China, 4 350 ground motion records at home and abroad were selected, and a quantitative study on the ratio of vertical to horizontal acceleration spectra according to the site category and magnitude classification was carried out. The results show that the ratio of vertical to horizontal response spectra generally exceeds the fixed value of 0.65 given by the current codes such as Code for seismic design of buildings (GB 50011—2010), and is significantly affected by the site category and seismic intensity. Therefore, it was proposed to introduce vertical site coefficient to characterize the vertical ground motion effect, and the method of calculating the vertical site coefficient, which is applicable to code for seismic design of railway engineering, was determined through the trial calculation and comparison with the relevant provisions of Specifications for seismic design of highway bridges (JTG/T 2231-01—2020). The peak ratios of vertical and horizontal acceleration response spectra under different site categories and seismic defense intensities were calculated, and the proposed values of vertical site coefficients were given. The research findings presented in this paper can serve as a reference for determining the value of vertical acceleration design spectra in seismic design codes for railway engineering.

In the seismic response analysis of locally irregular sites such as basins under plane wave incidence, it is usually assumed that the input seismic motion is of a single wave type, i.e., SV wave, SH wave, or P wave. However, the actual incident motion is generally a multi-dimensional coupled shaking case. Based on the spectral element method, the ground motion response of a three-dimensional semi-ellipsoidal sedimentary basin under the vertical incidence of plane waves is simulated. By analyzing the distributions of peak ground acceleration (PGA) and the corresponding amplification factor, the seismograms along the surface point profile, and the response spectrum ratio distribution at the characteristic frequencies, the ground motion amplification features of the sedimentary basin under multi-dimensional ground motion input are investigated through comparisons with the results of single wave type incidence. The results show that compared with the unidirectional horizontal seismic excitation, the bidirectional horizontal seismic input has a significant amplification effect on ground motion in the basin, and the maximum amplification factor can reach 1.87. Considering the influence of simultaneous input of bidirectional horizontal ground motion, the distribution characteristics of the peak ground acceleration will change significantly. The superposition and interference of waves propagating in different directions result in an asymmetrical PGA distributions. The bidirectional ground motion input makes the wave propagation characteristics more complex, and the location of the strongest ground shaking changes. In addition to the amplification of the response spectrum value, the bidirectional input also has a certain influence on the distribution of the predominant period.

Soil dynamic parameters are crucial calculation parameters for the seismic response of soil. However, there is currently insufficient theoretical research on soil dynamic characteristics in Heilongjiang Province. To address this, we analyzed data on the dynamic shear modulus ratio and damping ratio of 286 groups of clay, clayey soil, and sandy soil at different burial depths in the region. We derived the characteristic parameters of each group of soil dynamic parameters and statistically obtained a fitting formula for the variation of these parameters with soil burial depth. Using this formula, we calculated the dynamic shear modulus ratio and damping ratio data of different soil types at different burial depths and verified the rationality of the fitting formula. We established six soil seismic response models using soil types with abundant data and input typical seismic motions in Heilongjiang Province. We calculated the fitting parameters a₁, a₂, E(λ_max), E(M), etc. of the fitting formula and studied the influence of the variability of characteristic parameters on peak ground acceleration, characteristic period, and plateau value of ground response spectrum by scaling the fitting parameters. Results show that with the increase of a₁ and E(λ_max) the damping ratio increases, resulting in a decrease in the site amplification factor F_PGA and an increase in the characteristic period T_g. The increase of a₂ and E(M) will lead to a decrease in the damping ratio, resulting in an increase in F_PGA and a decrease in T_g. The plateau value β has a large variability, fluctuating within a certain range without a definite increasing or decreasing trend. Variability has the greatest impact on F_PGA, followed by its impact on T_g, and then on β. The soil seismic response is the most sensitive to the variability of a₁. As the intensity of the input seismic motion increases, the error increases. Overall, this study provides necessary supplements to the research on soil dynamic parameters in Heilongjiang Province.

Based on the actual damage and the mechanical characteristics of the component, a dumbbell-shaped component is proposed by dividing the wall units along the midline of the span. To verify the phenomenon of internal force and deformation concentration during the loading process of dumbbell-shaped components, quasi-static tests of rectangular and dumbbell-shaped components with equal initial stiffness were designed. Wall shear strains and relative displacements at different positions were tested. The analysis results show that the dumbbell-shaped components undergo shear failure first, with damage concentrated between windows, causing the floor to collapse vertically along the side of the dumbbell-shaped component. Shear strains on the cross-section of dumbbell-shaped components are significantly higher than those of rectangular components, and the strain ratio gradually increases with displacement. Relative displacements on the upper and lower sides of the wall between windows indicate that as the loading displacement increases, the ratio of the upper wall to the wall between windows gradually decreases, while the displacement ratio between the wall between windows and the lower wall gradually increases. Both strain and displacement indicate that during the deformation process, internal forces and deformations gradually concentrate towards the wall between windows. Based on the analysis results, the collapse mechanisms of masonry structures and masonry-frame hybrid structures are discussed.

To characterize the mechanical properties of 7075 high-strength aluminum alloy, three specimens for the monotonic tensile test and five specimens for cyclic loading were designed and fabricated. Based on the Ramberg-Osgood model, numerical fitting was carried out separately for the monotonic tensile stress-strain curves and cyclic loading skeleton curves of aluminum alloy bars. A comparative analysis was conducted on the tensile mechanical properties and hysteresis mechanical properties of 7075 high-strength aluminum alloy. The combined hardening parameters for high-strength aluminum alloy were calibrated, and a combined hardening hysteresis constitutive model was established. Using the software ABAQUS, a numerical analysis model of high-strength aluminum alloy was created, and the simulation results were compared with and validated against experimental results. The results indicate that 7075 high-strength aluminum alloy exhibits excellent hysteresis performance, and the Ramberg-Osgood model shows good applicability to the monotonic mechanical properties of high-strength aluminum alloy. The finite element simulation results based on the combined hardening model are in good agreement with the test results. The calibrated combined hardening model can be used for the seismic behavior analysis of structures reinforced with high-strength aluminum alloy.

The beam-column joint with replaceable energy dissipators has the advantages of convenient and economical repair after an earthquake. For a bending shear replaceable component with simple structure, easy construction, stable energy consumption capacity, and consistent tensile and compressive mechanical properties, a refined finite element model of flexural-shear replaceable energy dissipators was established. Then, the failure mode, hysteresis curve, skeleton curve and stress distribution state of the component were analyzed. The influence of parameters such as height-width ratio, width-thickness ratio of limb columns for replaceable energy dissipators, and overall slenderness ratio of energy dissipation zone was considered, and the effects on skeleton curves, stiffness and equivalent viscous damping coefficient of energy dissipators were systematically discussed. The analysis results showed that when the height-width ratio of limb columns in energy dissipators was greater than 4.0, the limb columns were prone to buckling behavior, and the recommended threshold value of the height-width ratio is 1.3~4.0. Increasing the width-thickness ratio of the energy dissipators decreases the initial stiffness and bearing capacity of the specimen, and it was recommended that the width-thickness ratio of limb columns should be no more than 2.5. When the slenderness ratio of the energy dissipation zone was large, its out-of-plane stability and energy dissipation capacity would be weakened, it is suggested the slenderness ratio of the energy dissipation zone not exceed 48. When height-width ratio of limb columns were less than 1.0 and greater than 2.5, the error between the theoretical prediction and the finite element calculation of the yield strength for flexural-shear replaceable energy dissipators was large, the latter was about 35% and 32% higher than the former respectively, so further research on the theoretical strength prediction model is needed to improve its prediction accuracy. The research results can provide reference for the seismic design of the flexural-shear energy dissipators.

To investigate the seismic performance of partially encased composite columns-reinforced concrete shear walls (referred to as PEC column-RC shear walls), two different connection types were designed and subjected to low-cycle reversed loading tests. The study focused on their failure processes, hysteretic behavior, energy dissipation capacity, stiffness degradation, and strength degradation. Additionally, finite element models were developed to simulate their behavior, which were validated against the experimental results. The models were also used to analyze the seismic performance of PEC column-RC shear walls under different concrete strength grades and axial compression ratios. The results indicate that PEC column-RC shear walls ultimately experience shear failure, yet they exhibit high ductility and energy dissipation capacity, demonstrating excellent seismic performance. In practical engineering applications, the weak-axis connection method for PEC columns can effectively meet seismic performance requirements. As the concrete strength increases, the load-bearing capacity of PEC column-RC shear walls improves, although the ductility decreases. With an increase in the axial compression ratio, the rate of increase in load-bearing capacity diminishes. It is recommended to keep the axial compression ratio below 0.4 in practical engineering designs.

Hybrid simulation with model updating utilizes the test data to identify the parameters of the experimental substructure and updates the model of the numerical substructure, effectively avoiding the errors induced by the inaccurate parameters of the numerical substructure in traditional hybrid simulation. To ensure the accuracy of parameter identification, the selected constitutive parameters must be observable and highly sensitive. The existing local parameter sensitivity analysis method belongs to qualitative analysis and cannot specifically and quantitatively evaluate the sensitivity of the parameters. Therefore a parameter sensitivity analysis method based on correlation analysis is put forward. This method quantitatively evaluates the parameter sensitivity of constitutive parameters by calculating the correlation coefficient between constitutive parameters and restoring force, and the calculation is simple. The parameter sensitivity analysis of concrete employing the Kent-Scott-Park constitutive model and the composite damper using the trilinear constitutive model is conducted respectively, and the results are compared with those obtained by the local parameter sensitivity analysis method. The results show that the higher sensitivity parameters selected by the two methods for the constitutive parameters of concrete are consistent, while the local parameter sensitivity analysis method is not suitable for the composite damper. The proposed method can determine the parameter sensitivity of the constitutive parameters of the composite damper. A six-story steel frame structure equipped with a composite damper was subjected to a hybrid simulation with model updating numerical simulation using different model update methods. The effects of parameter identification were compared and it was found that the constitutive parameters selected by the proposed method were easier to identify, and the hybrid simulation with model updating numerical simulation had higher accuracy and efficiency, which verified the correctness and effectiveness of the method.

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.