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学者姓名:李小军
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Abstract :
Soil nonlinear behavior displays noticeable effects on the site seismic response. This study proposes a new functional expression of the skeleton curve to replace the hyperbolic skeleton curve. By integrating shear modulus and combining the dynamic skeleton curve and the damping degradation coefficient, the constitutive equation of the logarithmic dynamic skeleton can be obtained, which considers the damping effect in a soil dynamics problem. Based on the finite difference method and the multi-transmitting boundary condition, a 1D site seismic response analysis program called Soilresp1D has been developed herein and used to analyze the time-domain seismic response in three types of sites. At the same time, this study also provides numerical simulation results based on the hyperbolic constitutive model and the equivalent linear method. The results verify the rationality of the new soil dynamic constitutive model. It can analyze the mucky soil site nonlinear seismic response, reflecting the deformation characteristics and damping effect of the silty soil. The hysteresis loop area is more extensive, and the residual strain is evident.
Keyword :
seismic response seismic response mucky soil mucky soil logarithmic dynamic skeleton logarithmic dynamic skeleton time-domain dynamic constitutive model time-domain dynamic constitutive model dampening effect dampening effect
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GB/T 7714 | Dong, Qing , Chen, Su , Jin, Liguo et al. Time-domain dynamic constitutive model suitable for mucky soil site seismic response [J]. | EARTHQUAKE ENGINEERING AND ENGINEERING VIBRATION , 2024 , 23 (1) : 1-13 . |
MLA | Dong, Qing et al. "Time-domain dynamic constitutive model suitable for mucky soil site seismic response" . | EARTHQUAKE ENGINEERING AND ENGINEERING VIBRATION 23 . 1 (2024) : 1-13 . |
APA | Dong, Qing , Chen, Su , Jin, Liguo , Zhou, Zhenghua , Li, Xiaojun . Time-domain dynamic constitutive model suitable for mucky soil site seismic response . | EARTHQUAKE ENGINEERING AND ENGINEERING VIBRATION , 2024 , 23 (1) , 1-13 . |
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This paper proposes a novel damping model with negative stiffness known as the half-cycle negative-stiffness damping model. Analysis of a single degree of freedom (SDOF) system demonstrated that the half-cycle negative-stiffness damping model has negative stiffness and energy dissipation. The equivalent negative stiffness of the model was derived from the frequency response analysis of the system. An alternating transmission system and a one-way friction system were developed to assemble a half-cycle negative-stiffness damping device (HCNSDD), which can generate a half-cycle negative-stiffness damping model. A mechanical model was developed to represent the force-displacement relationship of the proposed HCNSDD. A HCNSDD specimen was manufactured and examined using experimental tests. The HCNSDD exhibits half-cycle negative-stiffness damping and stable mechanical properties, demonstrating the feasibility and effectiveness of the proposed HCNSDD. Finally, a finite element simulation approach for HCNSDD was presented, and the performance of seismic vibration control of HCNSDD was evaluated using a multidegree-of-freedom system.
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GB/T 7714 | Sun, Tianwei , Peng, Lingyun , Ji, Xiaodong et al. A Half-Cycle Negative-Stiffness Damping Model and Device Development [J]. | STRUCTURAL CONTROL & HEALTH MONITORING , 2023 , 2023 . |
MLA | Sun, Tianwei et al. "A Half-Cycle Negative-Stiffness Damping Model and Device Development" . | STRUCTURAL CONTROL & HEALTH MONITORING 2023 (2023) . |
APA | Sun, Tianwei , Peng, Lingyun , Ji, Xiaodong , Li, Xiaojun . A Half-Cycle Negative-Stiffness Damping Model and Device Development . | STRUCTURAL CONTROL & HEALTH MONITORING , 2023 , 2023 . |
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Abstract :
Since the 9/11 incident, the research on nuclear power plants (NPPs) against the impact of large aircraft has gradually become the key research content in the field of national defense. Based on the experimental data, this paper establishes a refined finite element (FE) model to investigate the dynamic response and failure mode of nuclear containment under the impact of large aircraft. Firstly, the FE model is established according to the scale test, and its accuracy is verified. Then, the prototype nuclear containment is established, and the effects of aircraft impact speed, impact angle, and impact height on the dynamic response of nuclear containment are discussed. The results reveal that when the impact velocity of the aircraft is greater than 250 m/s, the fuselage, except the wing, penetrates into the nuclear containment. When the impact velocity reaches 300 m/s, the penetration size of the structure decreases. The increase in impact angle will significantly decrease the damage caused by aircraft to the structure. When an aircraft with a speed of 100 m/s impacts the nuclear containment at less than 30 degrees, the fuselage will penetrate into the containment. In addition, this paper summarizes two distinct failure modes of aircraft impact on nuclear containment, which provides a reference for research related to aircraft impact on nuclear containment.
Keyword :
Impact Impact Large aircraft Large aircraft Nuclear power plant Nuclear power plant Failure mode Failure mode Dynamic response Dynamic response
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GB/T 7714 | Zhou, Longyun , Li, Xiaojun , Yan, Qiushi et al. Study on the dynamic response of reinforced concrete nuclear containment under the impact of large aircraft [J]. | NUCLEAR ENGINEERING AND DESIGN , 2023 , 417 . |
MLA | Zhou, Longyun et al. "Study on the dynamic response of reinforced concrete nuclear containment under the impact of large aircraft" . | NUCLEAR ENGINEERING AND DESIGN 417 (2023) . |
APA | Zhou, Longyun , Li, Xiaojun , Yan, Qiushi , Li, Xiaohu . Study on the dynamic response of reinforced concrete nuclear containment under the impact of large aircraft . | NUCLEAR ENGINEERING AND DESIGN , 2023 , 417 . |
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Abstract :
The seismic responses of three-dimensional (3D) concave topography sites were calculated by the combination method of finite element discrete model, the viscoelastic artificial boundary and the central difference integral formula, and the characteristics and differences of the influence of pyramid-shaped, hemisphere-shaped and prism-shaped concave topographies in homogeneous elastic half space on site ground motion were analyzed under the vertical incidence of P wave and SV waves. (1) The influence of different shapes of concave topographies on site ground motion is significantly different, namely, the prism-shaped concave topography>the hemisphere-shaped concave topography>the pyramid-shaped concave topography, but the differences between the different concave topographies are more manifested in the medium frequency range. (2) Concave topographies have a complex scattering effects on seismic waves. Whether it is vertically incident P wave or vertically incident SV wave (only vertical or horizontal seismic motion input), it can produce significant ground motions in both directions in and near the sag area, and while SV wave is vertically incident, the wave scattering of concave topography is more intense, and furthermore the amplitude of ground motion in vertical direction generated by SV wave is even greater than that in horizontal direction. (3) The concave topography may cause the topographical edge effect of ground motion, and the ground motion at the edge of prism-shaped concave is significantly amplified, while this effect is relatively weak in the pyramid-shaped and hemisphere-shaped concave topographies. The study reveals that the steep degree of the concave edge has a significant impact on site ground motion, and that the edge effect of concave topography may exist and is closely related to the steep degree of the concave edge. This research result gives an important hint for the analysis of practical engineering problems, that is, the rational treatment of concave edge parts should be paid special attention to when establishing a simplified analysis model of concave topography. The research results can be applied to the engineering construction in mountainous areas, especially bridge and dam construction, and provide a reference for its seismic fortification to consider the characteristics and differences of different shapes of concaves on site ground motion, especially the possible topography edge effect.
Keyword :
topography edge effect topography edge effect concave topography concave topography viscoelastic boundary viscoelastic boundary site ground motion site ground motion topography influence topography influence
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GB/T 7714 | Li Xiao-jun , Ren Peng-liang , Wang Yu-shi et al. Comparison and analysis of the influence of different shapes of 3D concave topographies on site ground motion [J]. | ROCK AND SOIL MECHANICS , 2023 , 44 (11) : 3327-3338 . |
MLA | Li Xiao-jun et al. "Comparison and analysis of the influence of different shapes of 3D concave topographies on site ground motion" . | ROCK AND SOIL MECHANICS 44 . 11 (2023) : 3327-3338 . |
APA | Li Xiao-jun , Ren Peng-liang , Wang Yu-shi , Li Zai-xian , Zhong Kang-ming , Dong Qing . Comparison and analysis of the influence of different shapes of 3D concave topographies on site ground motion . | ROCK AND SOIL MECHANICS , 2023 , 44 (11) , 3327-3338 . |
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Abstract :
The diffuse field theory can comprehensively consider the contributions of various types of wave fields in ambient noise. The noise horizontal-to-vertical spectral ratio (NHV) based on diffuse field theory links surface observation with an intrinsic property of the underground medium. Naturally, it allows for the inversion of the velocity structure of soil layers. There is an urgent need to develop fast and effective NHV inversion tools to estimate velocity structure for soil layers. Combining the genetic-simulated annealing algorithm and forward calculation of NHV based on diffuse field theory, we proposed a global inversion method to determine the velocity structure of soil layers. The sensitivity analysis of the model parameters shows that the Vp, Vs and h of the soil layer and the Vs of the rock layer are the main affecting factors of NHV, the influence of the density of soil and rock layers on NHV can be ignored. Through the verification of synthetic cases, the observation of the Xiangtang vertical array, and comparison with a similar method, we have proved that good inversion results can be obtained using our proposed method. This proposed method can offer an efficient and low-cost way to estimate site velocity structures.
Keyword :
Noise horizontal-to-vertical spectral ratio (NHV) Noise horizontal-to-vertical spectral ratio (NHV) Inversion Inversion Velocity structure Velocity structure Soil layers Soil layers Ambient noise Ambient noise
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GB/T 7714 | Rong MianShui , Wang JiXin , Li XiaoJun et al. Inversion method for velocity structure of soil layers by ambient noise and its application [J]. | CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION , 2023 , 66 (2) : 530-545 . |
MLA | Rong MianShui et al. "Inversion method for velocity structure of soil layers by ambient noise and its application" . | CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION 66 . 2 (2023) : 530-545 . |
APA | Rong MianShui , Wang JiXin , Li XiaoJun , Liu AoYi , Kong XiaoShan , Li Hang . Inversion method for velocity structure of soil layers by ambient noise and its application . | CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION , 2023 , 66 (2) , 530-545 . |
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Abstract :
Following the site classification methods proposed the Chinese seismic code (Code16) and the Next Generation Attenuation (GMX), the site conditions of 62 strong motion observation stations located in Sichuan, China were classified based on their site conditions. Then, the site amplification coefficients and high-frequency attenuation parameters (kappa(0)) of these selected stations were used to investigate the local site effect characteristics of each site classes in average sense. The result shows that, in the range of Code16 site class II, at frequencies above 10 Hz, the amplification of GMX site class C is significantly enhanced by the topographical effect due to narrow mountainous valley site condition; whereas at frequencies below 5 Hz, the amplification of GMX site class D is noticeably enhanced by the deep soft sediments. Considering the source slip model, the differences of quality factor between mountainous and basin aeras, the local site effects, and the average stress drop of regional aftershocks, the acceleration time series, Fourier Amplitude spectrum (FAS) and 5%-damped pseudo-spectral acceleration (PSA) of 9 stations located within 100 km rupture distance (R-rup) range with respect to the 2022 Lushan M(S)6.1 earthquake were simulated using the stochastic finite-fault simulation method. The result shows that, the simulated time series fit well with the S-wave portion of observation. Moreover, at period shorter than 8 s, the shapes of simulated FAS and PSA matched those of observations. The satisfactory simulation result supported that the current earthquake is most likely to be an aftershock of the 2013 Lushan M(S)7.0 earthquake. Moreover, the simulation result captured the obvious directivity effect observed when R-rup < 35 km. Finally, taking the average site amplifications and kappa(0) values of each site classes into account, the attenuation characteristics with respect to R-rup of simulated and observed peak ground acceleration (PGA), peak ground velocity (PGV), and spectral acceleration at periods of 0.5 s, 1.0 s, 5.0 s, and 8.0 for 167 basin and 130 mountain stations with R-rup < 150 km were compared. The result indicates that, the attenuation rate of ground motion parameters and the levels of PGA and PGV of basin and mountain stations are similar. However, at period longer than 1.0 s, the spectral accelerations of basin are systematically larger than those of mountain area.
Keyword :
Directivity effect Directivity effect Strong ground motion Strong ground motion Lushan M(S)6.1 earthquake Lushan M(S)6.1 earthquake Site effect Site effect Stochastic finite-fault method Stochastic finite-fault method
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GB/T 7714 | Fu Lei , Xie Junju , Chen Su et al. Analysis of site amplification coefficient characteristics of Sichuan and its application in strong ground-motion simulation: A case study of 2022 Lushan M(S)6.1 earthquake [J]. | CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION , 2023 , 66 (7) : 2933-2950 . |
MLA | Fu Lei et al. "Analysis of site amplification coefficient characteristics of Sichuan and its application in strong ground-motion simulation: A case study of 2022 Lushan M(S)6.1 earthquake" . | CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION 66 . 7 (2023) : 2933-2950 . |
APA | Fu Lei , Xie Junju , Chen Su , Zhang Bin , Zhang Xu , Li Xiaojun . Analysis of site amplification coefficient characteristics of Sichuan and its application in strong ground-motion simulation: A case study of 2022 Lushan M(S)6.1 earthquake . | CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION , 2023 , 66 (7) , 2933-2950 . |
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Abstract :
It has been widely recognised that near-fault ground motions can be distinctly different from far-fault ground motions, in terms of their amplitudes and spectral characteristics, and there are a number of studies investigating the effects of near-fault ground motions on the structural response. However, only a few studies focus on underground tunnels, and most of them consider vertically incident seismic waves, neglecting the wave passage effect which is critical for long tunnels. This paper investigates the consequences of near-fault pulse-like ground motions on the seismic tunnel response, with an example of a tunnel embedded in saturated poroelastic soil. The input motions are represented by obliquely incident P1 waves, and the wave passage effect along the longitudinal direction is considered by a 2.5D modelling technique. The seismic tunnel response for near-fault pulse-like and far-fault ground motions is compared. Additionally, artificial ground motions, which have consistent acceleration response spectra with the near-fault pulse-like ground motions, but without velocity pulses, are generated to gain further insight into the contribution of velocity pulses. It is shown that the near-fault pulse-like ground motions can noticeably increase the tunnel internal forces, due to large seismic energy associated with the velocity pulses. For pulse-like ground motions with similar acceleration response spectra, the fling-step velocity pulse can be more detrimental to the tunnel than the forward-directivity velocity pulse. Moreover, the amplification effect of the near-fault pulse-like ground motions on the tunnel internal forces tends to be more prominent for large vertical angles of incidence, highlighting the significance of considering the oblique incidence case for seismic design.
Keyword :
Saturated poroelastic soil Saturated poroelastic soil Forward-directivity velocity pulse Forward-directivity velocity pulse Fling-step velocity pulse Fling-step velocity pulse Wave passage effect Wave passage effect Underground tunnels Underground tunnels Near-fault pulse-like ground motions Near-fault pulse-like ground motions
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GB/T 7714 | Zhu, Jun , Li, Xiaojun , Liang, Jianwen et al. Effects of pulse-like ground motions on tunnels in saturated poroelastic soil for obliquely incident seismic waves [J]. | SOIL DYNAMICS AND EARTHQUAKE ENGINEERING , 2023 , 173 . |
MLA | Zhu, Jun et al. "Effects of pulse-like ground motions on tunnels in saturated poroelastic soil for obliquely incident seismic waves" . | SOIL DYNAMICS AND EARTHQUAKE ENGINEERING 173 (2023) . |
APA | Zhu, Jun , Li, Xiaojun , Liang, Jianwen , Kontoe, Stavroula , He, Qiumei , Chen, Su . Effects of pulse-like ground motions on tunnels in saturated poroelastic soil for obliquely incident seismic waves . | SOIL DYNAMICS AND EARTHQUAKE ENGINEERING , 2023 , 173 . |
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Establishing a database of building exposures is an important basic work in earthquake insurance research. How to efficiently, accurately, and scientifically construct the risk exposure database of buildings has become a hot topic these days. Based on multi-source data, a system for extracting seismic information from urban buildings was constructed in the Tangshan urban area, and a perfect earthquake insurance risk database was established in this study. In the extraction system, the U-net identification method, spatial overlay and kernel density estimation method, Kriging interpolation method, statistical analysis, and multi-temporal land cover data analysis were used, respectively, to extract the information of footprint areas, use function, story number, structure type, and construction age of the urban buildings. The extraction results are stratified and randomly sampled, and the confusion matrix is introduced to verify the extraction effect. The results show that the building covers an area of about 50 million square meters in the urban area of Tangshan City. With the training and validation of the U-net model, the global accuracy of the building footprint areas recognition model is 71%. By comparing the results of manually determined real data with the extraction results of this study for a sample of 660 buildings, it was found that the overall accuracy rates of the extraction results of building function, story number, structure type, and construction age were 88.62%, 86.65%, 86.49%, and 85.58%, respectively, and kappa coefficients were all over 0.8. These indicate that the information on buildings extracted by the method of this study is accurate and reliable. This study can provide data and methods for the establishment of the exposure database of earthquake insurance and provide strong data support for pre-earthquake disaster prevention, post-earthquake emergency rescue, and disaster loss assessment.
Keyword :
China China structure structure buildings buildings footprint areas footprint areas use function use function construction age construction age story number story number Tangshan Tangshan
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GB/T 7714 | Zhang, Pan , Li, Xiaojun , He, Qiumei . Extraction of Building Information Based on Multi-Source Spatiotemporal Data for Earthquake Insurance in Urban Areas [J]. | APPLIED SCIENCES-BASEL , 2023 , 13 (11) . |
MLA | Zhang, Pan et al. "Extraction of Building Information Based on Multi-Source Spatiotemporal Data for Earthquake Insurance in Urban Areas" . | APPLIED SCIENCES-BASEL 13 . 11 (2023) . |
APA | Zhang, Pan , Li, Xiaojun , He, Qiumei . Extraction of Building Information Based on Multi-Source Spatiotemporal Data for Earthquake Insurance in Urban Areas . | APPLIED SCIENCES-BASEL , 2023 , 13 (11) . |
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Duration models are one of the important parameters in ground-motion simulations. This model varies in different study areas, and plays a critical role in nonlinear structural response analysis. Currently, available empirical models are being globally used in ground-motion simulations, with limited research focusing on path duration in specific regions. In this study, we collected 6,486 sets of three-component strong-motion records from 29 K-NET stations in the Sagami Bay, Japan, and its surrounding areas between January 2000 to October 2018. We extracted the effective duration of 386 pieces of ground-motion records by manually picking up the S-wave arrival time and calculating the significant duration. We then obtained the path duration model of the study area based on the empirical equation of dynamic corner frequency and source duration of Boore (2009). Compared with the results of the available empirical models, the Fourier spectrum of the simulated ground motion from our effective duration model showed higher accuracy in the long-term range, with less fitting residuals. This path duration model was then applied to simulate two earthquakes of MW5.4 and MW6.2, respectively, in the region using the stochastic finite-fault method with a set of reliable source, path, and site parameters determined for the study area. The simulation results of most stations fit well with observation records in the 0-30 Hz frequency band. For the MW5.4 earthquake, the simulated ground motions at KNG005/KNG010/SZO008 stations were relatively weak in the mid to high frequency band (1-30 Hz) because the quality factor and geometric diffusion model used in the simulation were the averages of the entire Sagami Bay region, causing a bias in the results of a few stations owing to local crustal velocity anomalies and topographic effects. For the MW6.2 earthquake, the simulated ground motions were relatively weak at all SZO and TKY stations, mainly because of the close distance from these stations to the epicenter and the complex seismic-wave propagation paths. The analysis suggests that the differences between the simulation results of the two earthquakes were mainly related to complex geological conditions and seismic-wave propagation paths.
Keyword :
path duration path duration Sagami Bay Sagami Bay effective duration effective duration stochastic finite-fault method stochastic finite-fault method
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GB/T 7714 | Chen, Shiyang , Li, Xiaojun , Fu, Lei et al. Determination and application of path duration of seismic ground motions based on the K-NET data in Sagami Bay, Japan [J]. | EARTHQUAKE SCIENCE , 2022 , 35 (4) : 263-279 . |
MLA | Chen, Shiyang et al. "Determination and application of path duration of seismic ground motions based on the K-NET data in Sagami Bay, Japan" . | EARTHQUAKE SCIENCE 35 . 4 (2022) : 263-279 . |
APA | Chen, Shiyang , Li, Xiaojun , Fu, Lei , Chen, Su . Determination and application of path duration of seismic ground motions based on the K-NET data in Sagami Bay, Japan . | EARTHQUAKE SCIENCE , 2022 , 35 (4) , 263-279 . |
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Abstract :
In the shaking table test of a soil-pile-bridge structure system, it is difficult to keep the similarity relations of the model structure and that of the model soil consistent. Due to the difference of geometry and material similarity ratios for the model structure and model soil, the determination of the duration compression ratio of input motions is a key problem. The spectrum characteristics of input motions will be varied by the duration compression ratio so that the seismic responses of structure and soil system will be affected. There are three commonly used approaches to determine the duration compression ratio of input motions in shaking table tests: the time similarity ratio of model structure; the time similarity ratio of model soil; and uncompressed. To study the influence of the duration compression ratio on the seismic response of a soil-structure system in shaking table tests, the El Centro record and the Wolong record were chosen as the input motions, and the durations were compressed by the three commonly used approaches in this paper. The influence of the duration compression ratios of the input motions on the acceleration response of a soil-pile-bridge structure system was compared and analyzed through a series of shaking table tests. The results showed that the duration compression ratio affected the acceleration response of the model soil and the model structure, and the effect was more obvious when the peak ground acceleration (PGA) was small. If the research is focused on the seismic response of the soil, it is recommended to use the time similarity ratio of the model soil to compress the input motions. If the research is focused on the seismic response of the structure, it is recommended to use the time similarity ratio of the model structure to compress the input motions. This study could provide a reference for the design of the shaking table test of a soil-pile-bridge structure system.
Keyword :
soil-pile-bridge structure system soil-pile-bridge structure system shaking table tests shaking table tests soil-structure interaction soil-structure interaction duration compression ratio duration compression ratio
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GB/T 7714 | Zhang, Zhi , Song, Chenning , Li, Xiaojun et al. Influence of the Duration Compression Ratio of the Input Motion on the Seismic Response of a Soil-Pile-Bridge Structure System in Shaking Table Tests [J]. | APPLIED SCIENCES-BASEL , 2022 , 12 (23) . |
MLA | Zhang, Zhi et al. "Influence of the Duration Compression Ratio of the Input Motion on the Seismic Response of a Soil-Pile-Bridge Structure System in Shaking Table Tests" . | APPLIED SCIENCES-BASEL 12 . 23 (2022) . |
APA | Zhang, Zhi , Song, Chenning , Li, Xiaojun , Qi, Xingjun . Influence of the Duration Compression Ratio of the Input Motion on the Seismic Response of a Soil-Pile-Bridge Structure System in Shaking Table Tests . | APPLIED SCIENCES-BASEL , 2022 , 12 (23) . |
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