The implementation of dissipative dampers between adjacent buildings can effectively mitigate structural vibration responses, with inerter dampers offering distinct advantages for controlling coupled structures. However, the performance of different types of inerter dampers in adjacent buildings requires further investigation. This study aims to determine the optimal parameters of various control devices for multi-story adjacent structures. A global optimization solver is employed, with displacement and acceleration of the flexible structure as the primary control objectives, while constraining the response of the rigid structure. Three damper types, namely, viscoelastic dampers (VED), tuned inerter dampers (TID), and tuned viscous mass dampers (TVMD), are individually applied to adjacent structures to evaluate the influence of structural period ratio and damper placement on seismic response. The control efficacy of VED, TID, and TVMD is systematically compared, and a novel hybrid control scheme combining TID and TVMD is proposed. Time-history analysis confirms the effectiveness of the optimized design. Numerical results indicate that inerter dampers (TID and TVMD) significantly reduce the seismic response of adjacent structures while requiring considerably smaller damping parameters than VED. Although the hybrid TID-TVMD system demands higher parametric requirements than single-damper configurations, it achieves superior balance in controlling both displacement and acceleration of the flexible structure.

To investigate the seismic response of single-hole with two-track shield tunnels and inside prefabricated internal structures, this paper adopts stratum-structure method and viscous-spring artificial boundaries, utilizing the concrete damage plasticity (CDP) model to structures and establish the finite element models based on the Shanghai airport link line. After simulating, analyzing, and comparing, the seismic response of single-hole with two-track shield tunnels under five earthquakes has obtained. The results reveal that: internal structures, which can effectively increase the lateral stiffness of tunnel and reduce the diameter deformation rate, are beneficial to the seismic performance of tunnel. However, due to the internal structures, the most severely damaged part of the tunnel will change. Although the under-track structure increases the transverse stiffness of tunnel, the side walls on both sides of middle box culvert will be the first damaged parts under seismic wave. The seismic performance of partition walls is the worst among all components, and its response is controlled by the medium to long periods of seismic wave. Damage to the middle partition wall is mainly concentrated on the top and bottom. The seismic performance of the tunnel structure is relatively good, while the seismic performance of the internal structure is relatively poor, especially the middle partition wall. Future design and research should focus on the partition walls.

On December 18, 2023, a magnitude 6.2 earthquake occurred in Jishishan County, Gansu Province, with a maximum intensity of Ⅷ degrees. In order to analyze the damage characteristics of different structural types of buildings constructed by the standard and self-built methods in the townships, a seismic damage survey was conducted on the buildings in the macro-seismological center of the earthquake-Dahejia Town. The typical seismic damage characteristics of reinforced concrete shear wall structures, masonry-concrete composite structures, reinforced concrete frame structures, and other structural types were summarized, and the causes of damage were analyzed. The results of the investigation and analysis show that the standard-built masonry-concrete composite structures and reinforced concrete shear wall structures suffered minor damage as a whole, which does not affect the continued use of the buildings. The load-bearing columns and beams of the standard-built frame structures are basically intact, but the infill walls are severely damaged, which affects the use of the building and the cost of later repair is relatively high. The self-built buildings are more severely damaged than the standard-built buildings, and the damage patterns are complex and diverse, which seriously affects the production and life of the residents. In view of the many problems in the earthquake-resistance of township houses, it is suggested that the relevant government departments organize professional units to carry out appraisal of existing buildings and provide multiple sets of repair and reinforcement schemes. For new and under-construction self-built houses, the regulatory intensity should be increased, and the professional skills of the personnel involved in house construction should be enhanced through training. For the urgently developing and constructing township areas, the relevant departments should strictly follow the relevant regulations of the seismic code, take the lead in the construction of civil houses, and improve the overall seismic capacity of the region.

The pile-columns of frame piers is a widely used substructure in bridge engineering. The current seismic design specifications for bridges require the pile to remain elastic following the capacity protection principle. Therefore, identifying the sensitivity of various design parameters to seismic demands of the piles is an important prerequisite for the capacity protection design of the piles. For this purpose, based on a coupled soil-pile-structure finite element modeling method, the sensitive parameters of pile-columns of frame piers to pile seismic demand are studied. Firstly, distribution mechanisms of bending moment under different earthquake intensity are investigated, together with understanding the contribution of ground surface tie beam to withstand the pile-shaft bending moment. On this basis, standardized seismic demand indicators representing the maximum bending moment of the pile, the corresponding depth, and the recommended reinforcement range are proposed. The sensitivity of tie beam, pile, column and soil parameters to the seismic demands of piles is analyzed. Based on the sensitivity parameter definition standards derived in this paper, the high and low sensitivity parameters of the pile seismic demand are identified. The research results can provide a reference for the seismic design of bridges supported by extended pile-shaft frames with ground surface tie beams in cohesionless soils based on pile capacity protection principle.

It is crucial to quickly and accurately assess the losses for post-disaster relief and reconstruction after earthquake disasters. This article focuses on the research of normalized business requirements for earthquake on-site disaster loss investigation and assessment. By establishing a unified earthquake on-site disaster loss investigation and assessment system, it optimizes the information transmission process at the earthquake on-site, improves the timeliness of earthquake information transmission, and achieves the flattening of survey data collection, analysis, and management. Through the implementation of functions such as calculating the earthquake damage index of sampling points, comprehensively evaluating the intensity map, and semi-automatically generating assessment reports, the system improves the efficiency of earthquake disaster response and the accuracy of disaster loss assessment, providing strong guidance and a basis for post-disaster reconstruction. At the same time, the accumulation and analysis of earthquake on-site loss investigation and assessment cases serve as a reference for future emergency response and risk assessment. Finally, this article also presents further research throughts and methods to gradually improve the system’s functionality, rendering it more practical and sustainable.

The construction of underground utility tunnels has developed rapidly, resulting in a large number of interchange utility tunnels, and the interchange nodes of the these tunnels are mostly cast-in-place as a whole. Due to the significant difference in lateral resisting stiffness in two orthogonal directions of the interchange utility tunnel, and the soil deformation is closely related to the buried depth of utility tunnel, the seismic response mechanism of the interchange utility tunnel is complex. In this paper, a response displacement method for the transverse seismic analysis of underground interchange utility tunnel is proposed. Taking a cross interchange cast-in-place utility tunnel as the research project, the load-structure model of the cross interchange utility tunnel is established via the response displacement method. The maximum relative deformation and its occurrence time between the layers of the interchange utility tunnel are studied, and the method in this paper is verified by the time history analysis method. Results indicate that for the underground interchange utility tunnel, the maximum relative deformation between the layers of interchange node does not occur simutaneously. Considering only the maximum relative deformation of the top slab and bottom slab of the interchange node may not be the most unfavorable condition for seismic analysis of the structure. It is necessary to calculate the maximum relative deformation between the layers of the interchange node to determine the most unfavorable condition of the overall structure. The method in this paper can accurately calculate the internal force and deformation response of underground cross interchange utility tunnel under seismic action, which is of reference value for the transverse seismic design of the underground interchange utility tunnel.

This paper proposes a novel prestressed reinforced concrete (RC) column reinforcement method by replacing traditional angle steel with spatial special-shaped steel structures, which enhances constraint effectiveness and construction efficiency through prestressing technology and bolt connections. Four specimens were designed and subjected to axial compression tests to obtain failure modes, load-displacement curves, and strain distribution patterns of different configurations. The study found that post-earthquake damaged RC columns exhibited a 24% reduction in ultimate axial compressive bearing capacity and 46% stiffness degradation. After prestressed lattice steel reinforcement, concrete crack propagation was effectively controlled with significantly reduced damage severity. The bearing capacity and stiffness reached 141% and 115% of the original column’s values respectively, accompanied by a 20% improvement in deformation capacity, demonstrating excellent reinforcement performance. The prestressed lattice steel provides substantial lateral confinement, inducing compressive stresses in reinforced components that enhance material properties and retard crack development. Finally, based on the section equilibrium method, a calculation formula for axial compressive bearing capacity of fully bolted prestressed lattice steel-reinforced seismic-damaged RC columns was established, laying a theoretical foundation for engineering applications of this innovative reinforcement technique.

Roller compacted concrete gravity dams have developed rapidly since the 1980s due to their advantage of fast construction speed. Generally, induced joints are set between the dam sections of roller compacted concrete gravity dams and the joints are cut discontinuously with a slotting machine, with the joint surface being non-exposed. The overall seismic response and safety of the dam considering the influence of induced joints are worth attention. This paper proposed a simulation method for the induced joints of roller compacted concrete gravity dams. Established a three-dimensional finite element model of a certain roller compacted concrete gravity dam. Calculated and analyzed the stress, deformation and plastic damage behavior under static and dynamic loads of the overall model of the roller compacted concrete gravity dam and compared it with a single dam section model to study the influence of induced joints on the dam seismic response. The results showed that the stress level and damage degree of the highest dam section in the riverbed are similar under the two models and the seismic responses of the single dam section model were greater in some parts. In addition, the overall model can simulate the damage and cracking process of the induced joints of the roller compacted concrete gravity dam and can more reasonably simulate the overall response of the dam, especially the stress distribution of the dam sections at both dam abutments.

The cost-effective ratio for the reinforcement of seismic damaged structures is proposed based on the estimated seismic economic loss and reinforcement cost. A performance-based optimal selection method is established. The cost-effective ratio and estimated repair time are adopted as quantitative indexes. Besides, the construction technology, construction time cost, and effect on building functions are qualitative indexes. The technique for order preference by similarity to ideal solution (TOPSIS) and combination ordered weighted averaging (C-OWA) were adopted as the mathematical method for optimal selection. Taking a certain typical concrete frame structure as the research object, based on the incremental dynamic analysis results of different seismic damage reinforcement schemes, a comparative and optimal selection study of the FRP reinforcement scheme, shock absorption reinforcement scheme, and seismic isolation reinforcement scheme for the seismic damaged structure was carried out. Results indicate that the proposed cost-effective ratio can provide a comprehensive and objective insight into promoting seismic performance from an economic perspective. Moreover, the performance-based optimal selection procedure can effectively provide a scientific basis for the construction decision-maker by combining objective situations and subjective willingness.

Real-time hybrid testing is an important test method for exploring the seismic performance of structures incorporating velocity-dependent components. However, current real-time hybrid tests encounter the challenge that the numerical substructure calculation efficiency fails to meet the real-time requirements, thereby restricting the application of this method in seismic tests of large-scale engineering structures. In order to improve the computational efficiency of the numerical substructures, a physical information neural network suitable for real-time hybrid testing is proposed, and a real-time hybrid testing method for neural network surrogate models is implemented. First, a neural network model was constructed based on different physical constraint equations. Then the seismic response of a two-story frame structure with a damper was numerically simulated by finite element software, and these simulation data were employed to train the network model. Finally, the trained physical information neural network was used to carry out real-time hybrid test simulation. The simulation results show that the physical information neural network has high prediction accuracy, among which the physical information neural network using resilience as the loss function has the highest accuracy. The real-time hybrid test method based on the physical information neural network agent model is feasible.