The fifth generation “seismic ground motion parameters zonation map of China” （GB 18306―2015），which was promulgated and implemented in China，introduced the vary rare earthquake effect for the first time. However，the current seismic design specifications still adopt the three-level defense principle. The seismic design for vary rare earthquake has become one of the urgent issues that need to be addressed in structural seismic design. Based on the identification method of continuous wavelet transform，this paper selects 12 pulse-like ground motions and 12 non-pulse seismic motions recorded in the Turkey mega earthquake on February 6，2023. The incremental dynamic analysis （IDA） is conducted on continuous pipelines and ductile iron pipelines to evaluate their seismic fragility. The fragility analysis results are compared with the failure probability obtained by empirical statistical method. The results show that the effect of pulse-like ground motions significantly increases the probability of serious structural damage for buried pipelines with different forms. Compared with continuous pipelines，ductile iron pipelines are more prone to damage underground motions，and are more sensitive to the pulse-like ground motion. The empirical statistical results based on actual seismic damage data are slightly lower than the failure probability of pipelines under non-pulse earthquake motion，but significantly underestimate the damage of buried pipelines under pulse earthquake motion. In this paper，the failure probability of different types of buried pipelines under pulse-like seismic motions is given，and the research results can provide a strong theoretical basis for the risk assessment and seismic design of buried pipelines under very rare and pulse-like ground motions.

There are a large number of ultra-large slope bridges in the rack railway line，and the settlement of bridge piers is difficult to avoid. It leads to the decrease of the smoothness of the railway line and threaten the safety and smoothness of the train. To solve this problem，based on the theory of vehicle-rack（track）-bridge dynamic interaction and gear dynamics，a coupled dynamic model of mountain vehicle-rack（track） -bridge system is established. The dynamic model considers the nonlinear meshing behavior of gear-rack and nonlinear contact behavior of wheel-rail in detail. The meshing behavior of gear-rack and the dynamic characteristics of vehicles under three different pier settlement modes （single pier settlement，continuous pier settlement and spaced pier settlement） are investigated，and the influence of different pier settlement modes on the vibration of vehicles is compared. The results show that the influence of pier settlement on the rack railway system is mainly reflected in the vertical and longitudinal acceleration of the vehicle，and the main frequency of vibration is 1~2 Hz and 8~9 Hz respectively. The effects of single pier settlement on the basic vibration characteristics of the rack-bridge system are similar to those of double pier settlement. But compared with double pier settlement，the effects of single pier settlement on the longitudinal acceleration of the vehicle are more significant，and the fluctuation of the meshing frequency is also significantly increased. Pier settlement will cause the increase of gear offset，and then lead to the instability of gear-rack meshing. When pier settlement is 6 mm，the problem of meshing apart begins to appear，which seriously threatens the operation safety of vehicles.

A large number of high-pier rigid frame bridges in the canyon areas are located in near-fault regions （hereinafter referred to as near-fault），and the seismic analyses should comprehensively consider the near-fault effect，site effect，and fluid-structure interaction when they are located in the water environment such as rivers，reservoirs，etc. Currently，most near-fault seismic records are used as consistent inputs，which may underestimate the seismic response of the bridges. At the same time，the discussion on the correlation between the seismic sources，site parameters，and seismic response of the bridges is unexplored. In this paper，the stochastic finite fault method and the boundary element method are combined to generate the multi-dimensional and multi-point ground motions of the overlying water-layer canyon sites near faults，and the analysis of the seismic response of the deep-water，large-span，high-pier rigid frame bridge in the near-fault canyon site is developed. The sensitivity of the response of piers and bearings to the seismic source and site parameters is investigated from the perspective of the whole physical process between the seismic source and the structure. The results indicate that the bridge response is most sensitive to the rupture surface size. On the whole，the influence of source parameters on the bridge response is more significant than that of site parameters. The site effect leads to the difference of the mean values of curvature ductility ratios of two main piers in longitudinal and transverse directions to be 85% and 88%. There are differences in the sensitivities of the main piers and bearings to each parameter. When the dip angle of the fault is between 33°~60°，the seismic response of the bridge shows a trend of increasing first and then decreasing，and the curvature ductility ratio of the main pier can differ by 35%. The water layer has an inhibitory effect on ground motions； however，the amplification effect of hydrodynamic pressures on the seismic response of the bridge is more prominent.

Based on a large depot project in Chongqing，the vibration and secondary noise characteristics and human comfort of the over-track buildings induced by metro operation in the depot are studied. The vibration characteristics of the depot are analyzed by field measurement. Combined with the numerical simulation method，the finite element model of the track-soil-depot-over-track buildings is established based on the metro-track coupling theory and the finite element theory. The vibration and secondary noise characteristics of the top buildings under train excitation are analyzed and evaluated. The combined annoyance model of vibration and secondary noise is constructed by combining psychology and fuzzy mathematics to analyze the human comfort，and the annoyance is used as the evaluation index. The results show that under the train operation，the vibration level of the throat area is the highest，and the vibration stability for different areas of the depot is as follows：the inner area > the throat area > the upper cover area. As the lateral propagation distance increases，the maximum Z vibration level of the platform decreases approximately linearly. The vibration peak of each building on the top is 12.5~20 Hz，and the main frequency band of secondary noise is 63~80 Hz. The vibration and secondary noise of each building attenuate with the increase of floors，but the vibration and secondary noise of residential building are amplified after 12 floors. The vibration of each building on the upper cover do not exceed the standard，but the secondary noise exceeds the standard in the commercial building，and the maximum exceeding value is 4.9 dB（A）. The annoyance results obtained by the joint annoyance model are in good agreement with the standard evaluation results，but the annoyance can refine the influence of vibration and secondary noise on human comfort. The model calculation shows that although the first floor of the residential building meets the standard limit，the joint annoyance is above 0.6 at night，and the evaluation using the joint annoyance rate model is more demanding.

Reconstructing the sound field environment inside the aircraft cabin during actual flight in a laboratory environment can provide a means for analyzing the acoustic environment inside the aircraft cabin，subjective evaluation，and noise reduction design. Based on the principle of sound pressure matching，this paper adopts a regularization method based on the L-curve method to solve the problem of inverse transformation of ill conditioned matrices. The effectiveness of the method in solving ill conditioned problems and improving reconstruction accuracy is demonstrated through simulation examples. Independently designed and built an aircraft cabin sound field reconstruction system. Conduct flight tests on transport aircraft，measure the noise at the pilot’s ear position under typical flight conditions，and use it as the target sound field. By using the sound pressure matching method，the full flight profile sound field reconstruction was achieved through the aircraft cabin sound field reconstruction system. Through sound field reconstruction experiments and subjective evaluation experiments，it shows that the reconstruction error in each frequency band of the one-third octave band is within 3 dB （A），and the subjective auditory fidelity and restoration are relatively high，providing support for subsequent analysis and subjective evaluation of the aircraft cabin acoustic environment.

In response to the challenging issue of low-frequency continuous spectrum reduction and isolation of ship equipment vibration，a vibration reduction method based on surface wave energy attenuation is proposed. Taking the rubber-fiberglass composite vibration system as an example，the damping characteristics of rubber surface waves are calculated using the finite element method. The influence of parameters such as thickness，damping coefficient，and Young’s modulus on surface wave attenuation is preliminarily explored. Experimental tests on rubber surface wave attenuation are conducted to validate the effectiveness of the surface wave attenuation method. The results demonstrate that the surface wave effect has a good vibration reduction performance，especially at high frequencies. The surface wave attenuation effect strengthens with increasing medium thickness，but not in a completely positive correlation. Reduction of the medium’s elastic modulus enhances the attenuation effect noticeably. Increasing damping is beneficial for surface wave attenuation. Compared to full-coverage rubber layers，local coverage of rubber layers on top of the isolating foundation provides better vibration reduction benefits.

In view of the light weight，small space and small amplitude requirements of electronic equipment for vibration isolation structure，the paper focuses on the isolation of low frequency vibration from its base. By introducing the cross-braced configuration，a concave cross braced plate model is proposed，the influence law of structural parameters on its low frequency vibration isolation performance is illustrated. Then，based on the design concept of cross-bracing，a concave sandwich phononic crystal structure model is proposed，and the influence mechanism of geometric parameters on its frequency response characteristics is revealed. After geometric parameter optimization and experimental verification，the vibration isolation structure model has excellent vibration attenuation characteristics in the low and wide frequency band. In 100~500 Hz，the attenuation efficiency of acceleration power spectral density above 70%. In 35~80 Hz，and 500~2000 Hz，the attenuation efficiency of acceleration power spectral density above 40%. Working displacement of the vibration isolation structure under 3 times standard deviation confidence is less than 3 mm. Therefore，it is suitable for the isolation of low frequency random vibration. In addition，the model has broad application prospects owing to its advantages of light weight，small volume，large bearing capacity and strong universality.

The riser bundle system is an important equipment to explore oil and gas in ocean engineering. Under ocean flows，upstream and downstream risers in tandem will experience vortex-induced vibrations and wake-induced vibrations，respectively，which seriously threatens the structural fatigue life. To predict the vibration responses of a downstream flexible riser，this paper develops a semi-empirical frequency-domain prediction method for wake-induced vibrations based on the classical vortex-induced vibration prediction method of a single flexible riser. Considering the wake shielding effect on the downstream riser due to the existence of the upstream riser，the reductive wake velocity becomes the flow velocity to excite the vibrations of the downstream riser. Then，the upstream-to-downstream diameter ratio is utilized to determine whether the frequency capture occurs. The added mass coefficient of the downstream riser will be adjusted when the frequency capture occurs，otherwise it is 1 constantly. Subsequently，the prediction is based on the resonance condition. The excitation coefficients from a series of forced oscillation tests of a rigid cylinder are approximate to be the wake-induced force coefficients. According to the balance between the modal structural damping force and the modal hydrodynamic force amplitudes，the modal amplitude can be non-iteratively solved. Afterwards，the wake-induced vibration displacements can be calculated based on the mode superposition method. By comparing prediction results with the experimental results，the proposed method can basically correctly predict the dominant frequency，displacement，strain and fatigue damage of the wake-induced vibration for the downstream flexible riser. Therefore，the present method is conducive to the multiple-riser system design in practical engineering.

Based on the three-dimensional elasticity theory，the smooth stochastic response model of three-dimensional sandwiched cylindrical shells is established by using the unified series method and the pseudo-excitation method （PEM）. The cylindrical shell subdomains are divided according to the interlayer property differences of the sandwich material，and the kinetic energy，strain energy，boundary potential energy and smooth random excitation work of each subdomain are established by using three-dimensional elasticity theory combined with the virtual excitation method. The mechanical coordination conditions between the layered subdomains are converted into coupling condition energies by the coupling penalty function method，and then the overall energy generalization of the sandwiched cylindrical shell is obtained by superposing the energies of each subdomain. The displacement components of each subdomain are constructed using a unified level expression and solved by combining the Rayleigh-Ritz method to obtain the stochastic response of the three-dimensional sandwiched cylindrical shell structure. The correctness of the stochastic response model is verified by comparison with literature and finite element results. Finally，the effects of thickness-to-radius ratio，lay-up angle of laminated-functional gradient sandwich material and power-law index on the random response of three-dimensional sandwiched cylindrical shell are analyzed.

The parameters design and vibration control of the system of Spar-floating offshore wind turbine （S-FOWT） coupled tuned mass damper-inerter （TMDI） under the joint wind-wave loads are studied in this paper. The theoretical model of 15-DOF Spar-FOWT with high fidelity is established based on multi-body dynamics modeling method and compared with FAST from both cases of damped free vibration and forced vibration. The damping efficiency of the FOWT-TMDI system under wind and wave loads is analyzed. In order to obtain the global optimal system parameters，the surrogate model method is used to optimize the time-varying and fully-coupled system. An example analysis shows that the model of 15-DOF Spar-FOWT has high fidelity which accurately secures the global dynamical characteristics of the wind turbine system. Meanwhile，the TMDI optimized by the proposed method has the expected control effect and the desired objective of “reduction in mass and stroke” is achieved. Compared with TMD，in addition，the TMDI has anticipative efficiency of the vibration reduction while reducing 75% of the mass and reducing about 80% of the damper stroke.