The seismic dynamic response of pile foundation in inclined liquefaction site is an important issue in the field of geotechnical seismic engineering. Based on the shaking table model test carried out by our research group and the OpenSees software platform，a two-dimensional integrated numerical model of inclined liquefied soil-pile group-structure interaction is established in this paper. The nonlinearity of pile-soil contact and the shear localization of soil layer are considered in the model. The rationality and effectiveness of the numerical simulation method are verified by comparing with the shaking table test results. On this basis，a typical inclined liquefied site-pile group-structure interaction finite element model is established to discuss the influence of different overlying crust on the seismic response of site and structure system. The calculation results show that with the increase of the thickness of overlying crust，the pore pressure ratio in the saturated sand decreases，the horizontal residual displacement of soil decreases，and the displacement of pile body and the pile curvature decrease. The effect of the strength of overlying crust on the dynamic response of pile foundation is more obvious. The increase of the thickness of overlying crust can reduce the liquefaction degree of sand and improve the mechanical performance of pile foundation.

In order to improve the energy absorption and safety of the energy absorption hydraulic support，a multi-layer lattice energy absorption device is designed. The basic structure of pyramid lattice energy absorption device is designed according to the structure and energy absorption space of energy absorption support column. The maximum energy absorption of the energy absorption device，the maximum mean of the support force within the allowable range，and the minimum fluctuation coefficient of the support force are taken as the optimization objective function，the base diameter and span of the pyramid cell are taken as the optimization design variables，and the constraint conditions are taken as the peak and mean of the support force of the energy absorption device within the allowable range. The Workbench software is used to optimize the structural parameters of the energy absorption device with the pyramid height of 30 mm，40 mm and 50 mm respectively. Three groups of optimization solutions are obtained and the optimal structural parameters are determined by comparative analysis. The single-layer energy absorption device with the optimal parameters reduced in the compression experiment was used for experimental analysis，and the results show that the absorption energy is 4.18716 kJ. The calculated energy absorption energy of the original single-layer energy absorption device is 113.05332 kJ，and the energy absorption energy of the whole energy absorption device is 565.2666 kJ. The relative error between the experimental results and the simulation results is only -9.92%. The energy absorption capacity of the new energy absorption device is at least 50% higher than that of the traditional thin-wall structure energy absorption device，which proves the effectiveness of the optimized design and the high energy absorption capacity of the energy absorption device.

Ground motion simulation can provide reference for buildings seismic design in areas lacking earthquake records. High frequency attenuating factor （κ） is an important parameter in ground motion simulation，controlling the drop of Fourier spectrum shape in the high frequency interval. Luring magnitude 6.8 earthquake records within 150 km of the epicenter are selected to develop κ. Parzen window is used to smooth the cluttered Fourier amplitude spectrums （FAS）. The frequency interval in FAS with the smallest p^H function is selected to fit the κ. The approach improves accuracy of identifying lowest and upper frequency，and the stability of the calculation. κ are calculated based on 20 stations of horizontal records and the distribution trend of κ is analyzed. The results show that FAS is gradually smooth with the increase of the window width，and it is significantly different from the original spectrum when the window width is larger than 1 Hz. Compared with 12 window widths，the window width of 0.4 Hz is the best. The window of 0.4 Hz width makes the curve smooth and the error of κ small. There is a significant directional difference in κ distribution. κ in EW direction increases with respect to epicenter distance，and κ in NS direction decreases with respect to PGA.

A practical analysis method for inertia damper energy dissipation systems composed of building structures with inertia dampers is proposed，including of concise closed-form solutions for the random seismic response and a practical setting strategy for inertia dampers. Based on the mechanical structure diagram of the series inertial damper and installation method in buildings，the coupled seismic motion equation of the energy dissipation system is established. In response to the difficulty in solving the damping and stiffness parameters in the actual dynamic equations of structures，an equivalent form of the uncontrolled structure represented by real modal vibration parameters is obtained based on finite element technology and dynamic principles，and the dynamic equation of the inertia damper energy dissipation system is reconstructed. Based on the quadratic decomposition method of the power spectral density function，closed-form solutions of the spectral moments of the building structure relative to ground displacement，interlayer displacement，and inertial damping force are derived. The correctness of the proposed concise closed form solution is verified through numerical examples，and the influence of real mode number on the 0~2 spectral moment of series response and the influence of floor position of inertia dampers on the seismic reduction effect of structures are studied. Results show that，using the number of actual vibration modes corresponding to the cumulative participation coefficient of 100% in the free vibration analysis of uncontrolled structures can achieve stable analysis accuracy and computational efficiency for the response analysis of multi-degree of-freedom energy dissipating structures，and to use reducing interlayer displacement of uncontrolled structures as the placement strategy for installation of inertial dampers is simple and feasible. This paper can provide a reference for the analysis of random ground motion response of complex building structure with series inertia capacity system.

The graph neural network models have been widely used in the field of fault diagnosis due to the advantage of abundant fault characterization capabilities. However，the existing models only utilize the local information among neighboring nodes when dealing with fault data，and fail to fully extract the global feature information. Meanwhile，in order to overcome the problems of low accuracy and insufficient generalization ability of single model. This paper proposes an ensemble method with multi-scale graph pooling feature fusion and graph convolutional network （MSGP-GCN）. The graph model is constructed from the original signal，and global information is obtained using graph pooling coarsening. Then weights are assigned at different scales based on the degree of the nodes，and the global information is used to update the node features in combination with the weights. The updated node features are input into different classifiers respectively，and the intelligent fault diagnosis result is obtained by majority voting strategy among these classification results. The proposed approach is fully verified by two fault datasets，the SEU simulation dataset and the real coal mill dataset. The experimental results show that the proposed model can effectively improve fault diagnostic accuracy and generalization ability in aforesaid two real datasets，and the average diagnostic accuracy reaches 98.31% and 97.21%，respectively.

Aiming at the robustness and stability of the vibration active control of motor-driven seawater pumps，a hybrid structure adaptive vibration active control strategy is proposed based on the Kalman filter （KF） algorithm，which establishes the system state prediction equations，state transfer matrix and measurement matrix，and builds a hybrid structure adaptive vibration active control system model. In order to improve the convergence performance of the algorithm，an online update strategy for the measurement noise covariance matrix is proposed. Simulation results show that the new control strategy effectively overcomes the strong correlation between the reference signal and the vibration source based on the classical Filtered x Least Mean Square algorithm （“FxLMS”），and realizes effective vibration active control under the premise that Gaussian white noise is used as the reference signal. The robustness，stability，and control effect of the proposed strategy are all superior to that of the FxLMS algorithm with a variable step size. The results provide theoretical support for engineering practice and have certain potential application value.

The complex response of the ocean thermal energy conversion platforms in the marine environment makes the structural safety design of cold seawater intake pipes suspended beneath the platform a challenge. Recent research has shown that the in-plane motion of the platform （heave oscillation） triggers out-of-plane vortex-induced vibration （VIV） in the riser connected to the platform and the complex vortex vibration response can cause rapid accumulation of fatigue damage to the riser，resulting in structural damage. In this paper，we focus on the VIV response of a free-hanging riser under multi-degree-of-freedom motion，which has rarely been reported in previous studies. A pool model test to measure the VIV strain information of the riser using fiber-optic grating strain gauges is carried out. After analysis of the experimental results，it can be found that： the maximum oscillation velocity at a large KC number is the main parameter affecting the dominant frequency of the out-of-plane vortex vibration response； the dominant frequency of vibration at a small KC number is twice frequency of the motion of the top platform. By comparing the experimental and numerical results of the free-hanging riser under the three degrees of freedom motion of the platform，it is found that the influence of the VIV on the overall dynamic response of the free-hanging riser is not negligible in this case. These results can provide a reference for further research on the VIV of the free-hanging riser taking into account the influence of the platform motion.

Aiming at the problem of the multi-order modal vibration of flexible wind turbine tower，a self anchored damping cable is designed in this paper，which converts the angular displacement of tower bending vibration into linear displacement，and drives the damper to dissipate energy and reduce vibration. Firstly，the tower-damper-cable vibration equation is established，and the analytical solution of the additional damping ratio provided by the damper cable for the first two-order bending vibration of the wind turbine tower is obtained. Then，the relationship between the damper viscosity coefficient and the additional damping ratio provided by the damper cable for the first two-order modal vibration of the wind turbine tower is analyzed through model experiment. The results show that the damping cable can provide a large additional damping ratio for the first two-order bending vibration of the tower，and the analytical solution of the additional damping ratio is in good agreement with the experimental results. Finally，based on the theoretical calculation formula of additional damping ratio，the influence of parameters on the damping performance of damping cable is analyzed.

To establish a 3D metro train-FST coupling model in the frequency domain，the key problem of the rail displacement at each moving wheel-rail contact point caused by all moving wheel-rail forces needs to be solved firstly. The matrix of the TFC establishes the relationship between them. Based on the established 3D discrete supported floating slab track model in the frequency domain，a method to calculate the TFC is put forward in this paper. Based on the relationship between the fixed and moving coordinate systems，the TFC to a moving point on FST can be written as the integration of the rail displacement response at a fixed point in the frequency domain caused by a moving harmonic load. After calculating the TFC of the 3D FST，some conclusions are obtained. At each excitation frequency，the TFC of a moving wheel-rail force to each wheel-rail contact point is the largest at the point of the force itself. Due to the moving of the wheel-rail force，there is a certain difference between the TFC of the front axle wheel-rail force to the rear axle wheel-rail contact point and that of the rear axle wheel-rail force to the rear axle wheel-rail contact point. In the same bogie，the TFC of the left wheel-rail force of the front axle to the right wheel-rail contact point of the same axle is similar to the TFC of that force to the left wheel-rail contact point of the rear axle. It is advisable to use a 3D model to finely analyze the dynamic characteristics of floating slab tracks.

Based on the strain gradient nonlocal Biot theory，the analytical solution of the dynamic response of the tunnel lining under the action of P-wave is obtained by using the wave function expansion method and the boundary conditions between saturated soil and lining with the deeply buried circular lining as the research object. The influence of non-local parameters and size factors on the dynamic stress concentration factor （DSCF） is investigated for different incident P-wave frequencies. The results show that when the incident wave frequency is low，the non-local parameters and size factor have almost no effect on the DSCF. As the incident wave frequency increases，the effects of the non-local parameters and size factor on the DSCF become more and more obvious. The non-local parameters are negatively correlated with the DSCF，and the size factor is positively correlated with the DSCF. The maximum dynamic stresses in the lining appear on the right side of the lining. With an increase of frequency，the DSCF in the lining shows obvious radial direction and the dynamic stresses in the lining appear in the right side of the lining. The maximum dynamic stresses in the lining all appear on the right side of the lining，With an increase of frequency，the DSCF in the lining shows obvious fluctuation along the radial direction，and the non-local parameters and size factor have little influence on the distribution pattern of the cyclic stresses in the lining.