This paper investigates the effects of spatial effects of seismic ground motions on the seismic responses of long-span cable-stayed bridges, considering their large range and notable variations in local site conditions. Shaking table tests were conducted on a cable-stayed bridge, and the dynamic responses (acceleration, displacement, and strain) of critical sections of the cable-stayed bridge were compared and analyzed. The results demonstrate the significant influence of spatial effects of ground motion on the dynamic responses of the cable-stayed bridge. Specifically, the analysis reveals that the wave passage effect has the least impact on the dynamic responses of the cable-stayed bridge, followed by the combined effect of the wave passage and coherence, while the combined effects of the wave passage, coherence, and local site conditions exert the largest influence. Taking the main tower as an example, the maximum acceleration, displacement, and strain responses increased by 55.69%, 62.37%, and 67.37%, respectively, when spatial seismic motions incorporating the wave passage effect, coherence effect, and local site effects were considered, as compared to uniform excitation. Consequently, the seismic responses of cable-stayed bridges may be underestimated if only uniform excitation or the wave passage effect is considered. It is therefore imperative to comprehensively account for the effects of wave passage, coherence, and local site conditions of the spatial ground motion in the dynamic response analysis of long-span cable-stayed bridges.

In order to study the seismic performance of the new adobe wall structural system. A one-story foot-scale new adobe wall building test model with plan size of 3.6 m×3.0 m and storey height of 2.45 m was designed and fabricated for the shaking table test, and El Centro waves and Yunnan Ludian (LD) waves were selected for the test to carry out unidirectional loading of seismic waves in the X and Y directions, respectively, and the test model was measured to be under the peak acceleration of 0.10、0.22、0.40、0.62、0.90 g, the spectral characteristics, acceleration response, displacement response, torsion response, and strain response of the dark column reinforcement were measured. The results show that: the model is only slightly damaged in the exceeding 9 degree rarefied intensity, and there is no obvious cracking and damage phenomenon under other seismic excitations. With the increase of seismic excitation, there is no obvious change in the self-resonance frequency of the model, and the acceleration amplification coefficient gradually decreases, with the maximum amplification coefficient of 3.666 at the roof. The angle of the interstorey displacement reaches the maximum of 1/399 when the peak acceleration is 0.62 g. The overall structural torsion is 1.599 at the peak acceleration of 0.62 g, and the displacement angle of 0.62 g reaches the maximum of 1/399. Because of the basic homogeneous symmetry, the structural torsion is 0.666 at the roof. Because the model is basically homogeneous and symmetric, the overall torsional effect of the structure is not obvious. The strain value of the steel reinforcement of the dark columns increases gradually with the increase of the seismic excitation, but the strain value of the steel reinforcement is small and the performance of the steel reinforcement fails to give full play. In summary, the new adobe wall model has good seismic performance, and the study provides a test basis for expanding the application range of adobe buildings.

In order to investigate the seismic performance of the suspended structure with viscous damper during earthquakes, the shaking table tests were carried out on two 1/20 scaled models of suspended structures, which were equipped with rigid rods and viscous dampers respectively. The dynamic characteristics, damping ratio, structural response and damping effect of model structures were researched. The test results show that compared with the common suspended model structure, the natural frequency of the suspension damping model structure is reduced, while the damping ratio is improved, especially the first frequency and the corresponding damping ratio. The peak accelerations of the top of the main structure and the fifth suspended-floor of the suspension damping model structure are less than those of the common suspended model structure, but the damping amplitude of the peak acceleration of the fifth suspended-floor is even up to 94.34%. The maximum displacement of the top of the main structure is also distinctly smaller than that of the common suspended model structure. Different seismic wave input has different damping effect, in which the effect of Taft wave is the best, the El Centro wave is the second, and the last is artificial wave. However, the maximum relative displacement between the main structure and the suspended-floor is greater than that of the common suspended model structure, which shows that the stronger the connection between the main and secondary structures, the smaller the relative displacement. It also indicates that the suspension damping model structure takes advantage of the swing of the suspended-floors and the viscous dampers to consume energy, so that the suspended structure with viscous dampers has better effect of energy dissipation and vibration reduction.

To investigate the impact of socket depth on the seismic performance of socket structures, a group of a cast-in-place pier and precast piers considering the variation of socket depth were designed and fabricated, of which the socket depths of the socket piers were 1.0d (where d represents the side length of the square pier), 0.8d, and 0.6d, respectively. Pseudo-static tests were conducted to analyze the damage patterns, hysteresis performance, and energy dissipation capacity of the piers, allowing for an examination of the influence of socket depth on their behavior. The test results demonstrate that the bearing capacity of the four groups of specimens is similar. The socketed piers with a socket depth of 1.0d exhibit damage patterns and hysteresis curves that are comparable to those of cast-in-place piers, indicating equivalent seismic performance. However, the ductility of the socket piers with embedment depths of 0.8d and 0.6d is weaker than that of the cast-in-place piers due to damage to the footing. By comparing the damage phenomenon, the relative relationship between the shear bearing capacity of the footing sidewall and the ultimate bearing capacity of the column is analyzed under the existing reinforcement ratio. As the socket depth of the pier decreases, the shear capacity of the groove sidewall decreases. This increases the probability of damage to the groove sidewall due to the reduced shear bearing capacity. Therefore, it is crucial to consider the relative relationship of the bearing capacity between the footing and the column when selecting the socket depth in the design to prevent damage in the footing position.

In order to analyze the trend and significance of the influence of different factors on the seismic performance of flexible connection autoclaved areated concrete(AAC) masonry filled wall steel frame structures, the feasibility of the modeling method and parameters selection was verified based on the results of pseudo-static tests, nine orthogonal finite element models were established by ABAQUS, and variable parameter analysis was carried out on axial compression ratio, reserved seam width, spring stiffness and height span ratio of models. The results show that the effects of reserved joint width, stiffness of energy-consuming materials, height span ratio and axial compression ratio on seismic performance of the structure decrease successively. On the whole, it is beneficial to increase the reserved joint width, reduce the stiffness of energy-consuming materials, high span ratio and axial compression ratio to improve the seismic performance of the structure. In actual application, the recommended value for the joint width between flexible connection AAC wall and frames is around 40 mm, and the stiffness of the filler between reserved joints is between 100~500 N/mm.

Traditional partially encased composite(PEC) beams usually adopt straight web plates, however, such web plates exhibit lower shear carrying capacity and lack mechanical interlock with concrete, which hinders their collaborative performance. To address the adverse effects of straight web plates, this study proposes the utilization of corrugated web plates as a cross-sectional replacement, leading to a novel corrugated web PEC beam. Through low-cycle repeated loading tests, the seismic ductility performance of the corrugated web plate PEC beam under earthquake loads was analyzed. The influence of flange thickness and shear-span ratio on the load-bearing capacity, failure mode, deformation capacity, hysteresis energy dissipation capacity, and stiffness degradation of the sinusoidal corrugated web PEC beam were investigated. The research demonstrated that a properly designed corrugated web plate PEC beam exhibited favorable load-bearing capacity and seismic ductility performance. The shear-span ratio significantly affects the failure mode and ductility of the beam, while increase the flange thickness effectively and enhances the load-bearing capacity of section. However, excessively thick flanges can impact the collaborative performance between the steel section and concrete. In this experiment, specimens with smaller flange thickness and larger shear-span ratios demonstrated high compatibility between the steel section and concrete, resulting in full utilization of their ductility and energy dissipation capacity.

In this study, based on the extended Kalman filter (EKF), an approach is proposed for identifying unknown ground motion time history and structural parameters by using the absolute acceleration measurements. First, the interfacial force of the lower boundary of the 1st floor is considered as the unknown excitation. The EKF-based approach is employed for the identification of this unknown excitation and the remaining structural stiffness parameters. Then, by using Fourier transform, the structural natural frequencies can be obtained from the acceleration measurements and used for identifying structural stiffness of the 1st floor. Finally, based on these identified structural parameters, the unknown interfacial force mentioned above is updated and employed for identifying ground acceleration with the aid of Newmark-β method. The effectiveness of the proposed approach is validated via a numerical frame structure and a five-story experimental model under shaking table tests.

There is a significant difference between the spatial distribution of ground motion along cross-fault regional areas (Ground motion in the area of the extreme proximity to the fault where the cross-fault engineering structures are located, referred to as cross-fault ground motion) and near-site ground motion. The lack of records on cross-fault ground motion poses challenges to studying the seismic resistance of cross-fault structures. This paper aims to outline the basic theory of the broadband hybrid method for simulating ground motion, and examines the distribution pattern of cross-fault ground motion using the Zemu River fault as a case study. The results indicate that the simulated cross-fault ground motion aligns with the fault sliding mode, displaying significant directional, up-disk effect, and slip-impact effect. Generally, the intensity of the simulated cross-fault ground motion follows a certain attenuation law. However, it is influenced by fault rupture, which can result in irregularities or even a counter-law phenomenon. Furthermore, the actual location of surface rupture and the zone of large slip along the fault have a substantial impact on the distribution pattern of cross-fault ground motion. By employing the broadband hybrid method, artificial cross-fault ground vibration time series can be generated to address the lack of recorded cross-fault ground motion. This methodology provides substantial support for research on the seismic resistance of cross-fault structures.

In order to reasonably represent the fully non-stationarity and randomness of the land acquisition seismic process, a random seismic model based on a combination of phase difference spectrum and power spectrum has been developed. Firstly, the relationship between phase difference and non-stationarity of seismic ground motion was elucidated, and the identification and statistical analysis of phase difference spectrum model parameters were carried out using strong motion records. Secondly, power spectrum models with deterministic and stochastic parameters were used to obtain the values of deterministic parameters and the normalized optimal probability distribution of stochastic parameters, respectively. Finally, by selecting representative point sets of basic random parameters, the corresponding representative time history set of seismic acceleration was obtained. The calculation example shows that the method in this paper only requires 2 or 4 basic random variables to simulate the seismic acceleration process with natural variability and rich probability information, and the simulated acceleration response spectrum fits well with the strong motion records. The study lays the foundation for applying probability density evolution theory to the random seismic response and seismic reliability refinement analysis of complex engineering structures.

As more and more water conservancy projects are constructed in the seismogenic fault zone in the western region, the probability of water conservancy projects encountering near-site vibration is also increasing. Due to the shallow buried depth of near-fault ground motions, the assumption of vertical incidence of seismic waves is no longer applicable. At present, there is little research on the seismic response of the intake tower under the oblique incidence of near-fault ground motions. In this paper, taking an engineering intake tower as an example, a three-dimensional plastic damage finite element analysis model of the intake tower is established, and the nonlinear response analysis of near-fault pulse ground motion SV wave under multi-angle oblique incidence is carried out. The results show that the displacement response of tower top under the oblique incidence of near-fault ground motion SV wave increases significantly, and the damage area and damage degree of tower body increase with the increase of angle.