Soil Dynamics and Earthquake Engineering最新文献

{"title":"Seismic fragility analysis of slopes: Method development, practical application and future prospects","authors":"Hongqiang Hu ,&nbsp;Yangjuan Bao ,&nbsp;Yu Huang ,&nbsp;Min Xiong ,&nbsp;Wuwei Mao ,&nbsp;Baoping Zou ,&nbsp;Xu Han ,&nbsp;Wenwen Wang","doi":"10.1016/j.soildyn.2024.109176","DOIUrl":"10.1016/j.soildyn.2024.109176","url":null,"abstract":"<div><div>Seismic fragility represents conditional probabilities of exceeding various limit states of an engineering system under a range of seismic hazard levels, which is a prerequisite procedure in the framework of probabilistic seismic risk assessment, performance-based earthquake engineering, and seismic resilience assessment. Recently, seismic fragility analysis has also emerged as an efficient tool to assess slope seismic performance and earthquake-triggered landslide risk. The increasing number of published studies concerning seismic fragility of slopes and slope-related earth structures demonstrates a substantial increase in interest in the topic of slope seismic fragility assessment. Many advanced technologies and methods have been employed for slope seismic fragility analysis, and great achievements have been made in previous studies. However, development in this field has not previously been reviewed. The objective of this study was to systematically review recent advancements and applications of seismic fragility in the field of slope engineering. Different fragility analysis methods in slope engineering, along with their features, advantages, and limitations, are introduced and reviewed. Prior necessary procedures in slope fragility analysis, including uncertainty quantification, the determination of slope engineering demand parameters, and the identification of optimal earthquake intensity measures, are given particular attention. The practical applications of slope seismic fragility analysis are also comprehensively introduced, such as using fragility curves to assess slope performance and risk, the selection of optimal strengthening measures in slope engineering, and fragility analysis of structures/infrastructure under earthquake-induced slope geological disasters. Finally, prospects, needs, and recommendations for future studies are also identified and provided.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109176"},"PeriodicalIF":4.2,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143101748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the influence of high-frequency spectral decay factor kappa (κ) within Delhi and its surrounding regions, India","authors":"Abhishek ,&nbsp;Babita Sharma ,&nbsp;Himanshu Mittal ,&nbsp;Manisha Sandhu","doi":"10.1016/j.soildyn.2024.109174","DOIUrl":"10.1016/j.soildyn.2024.109174","url":null,"abstract":"&lt;div&gt;&lt;div&gt;This study investigates the influence of kappa (κ) for Delhi and its surrounding regions. Path, as well as site dependent components of κ, are calculated from the available strong motion database. The estimated κ value using the NS component (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;κ&lt;/mi&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) ranges from 0.007 to 0.087s (±0.0001 to 0.029), while the EW component (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;κ&lt;/mi&gt;&lt;mi&gt;E&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) ranges from 0.013 to 0.099s (±0.001 to 0.058). The &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;κ&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;A&lt;/mi&gt;&lt;mi&gt;v&lt;/mi&gt;&lt;mi&gt;g&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;κ&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; values for the study region are in the range of 0.015–0.093s (±0.0005–0.003) and 0.002–0.040s (±0.0001–0.0002) respectively. The estimated κ values varied across sites and within sites in the study region highlighting the level of lateral crustal heterogeneities. No significant statistical relationship of κ with earthquake source was observed whereas the epicentral or hypocentral distances does not significantly affect the &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;κ&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; calculation for the study region. We also examined the seismic stations for &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;V&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;s&lt;/mi&gt;&lt;mn&gt;30&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; of HVSR as these metrics provided insights into the soil properties at the seismic stations. κ exhibits inverse correlation with &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;V&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;s&lt;/mi&gt;&lt;mn&gt;30&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; emphasizing the significant influence of the soil properties, bedrock depth, and sub-surface geology. The results indicate that hard sites (Class B) situated on Proterozoic meta-sedimentary rocks exhibit lower &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;κ&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; values than soft sites (Class D and E) located on Quaternary alluvial deposits. High values of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;κ&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; also observed for the stations lie near the Yamuna River due to the presence of soft sediment deposits. These soft sediments exhibit higher levels of damping and energy dissipation at high frequency during the earthquake. The hard sites close to different tectonic features show comparatively high &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;κ&lt;/mi&gt;&lt;mi&gt;o&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; that may be attributed to the existence of micro-fracture and degree of erosion. This study represents the first comprehensive investigation into site-specific κ values in this region, focusing on how seismotectonic and geological structures influence kappa across an extensive region. By analyzing these factors, the research aims to enhance our understanding of κ variability and its implications for regional seismi","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109174"},"PeriodicalIF":4.2,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of geosynthetics reinforcement on seismic behavior of coral sand revetment breakwater subjected to mainshock-aftershock sequences","authors":"Lin Zhou ,&nbsp;Rui Sun ,&nbsp;Jian-Feng Chen ,&nbsp;Cheng-Zhi Xia ,&nbsp;Hua-Ning Wang","doi":"10.1016/j.soildyn.2024.109190","DOIUrl":"10.1016/j.soildyn.2024.109190","url":null,"abstract":"<div><div>To date, numerous coral sand revetment breakwaters have been constructed in oceanic regions to resist wave impact and scour. However, frequent earthquakes significantly threaten their stability, especially during mainshock-aftershock sequences, where aftershocks can further exacerbate the risk of damage or collapse. This study proposes a reinforcing countermeasure, i.e., geosynthetics reinforced soil technique, to mitigate seismic deformation and enhance the resilience of revetment breakwaters against earthquakes. A series of shaking table tests were conducted on coral sand revetment breakwaters to examine the effect of geogrid reinforcement on their seismic performance under mainshock-aftershock sequences. Additionally, the reinforcement mechanism of geogrid was elucidated through supplementary cyclic triaxial tests. The results indicate that acceleration amplification intensifies during aftershocks, while geogrid reinforcement mitigates this detrimental effect. The inclusion of geogrid also decreases the buildup of excess pore water pressure (EPWP) under mainshock-aftershock sequences. Coral sand shear dilation results in the generation of notable negative EPWP within revetment breakwaters, and more significant negative EPWP oscillation, compared to the aftershocks, is observed in the mainshock. Additionally, geogrid decreases the maximum cumulative settlement in reinforced revetment breakwaters by over 54 % compared to unreinforced structures. The cumulative damage induced by aftershocks exacerbates the damage to coral sand revetment breakwaters, leading to the emergence and rapid progression of lateral displacements. Nevertheless, geogrid reinforcement mitigates this adverse effect and prevents the formation of plastic slip planes, thereby altering the deformation pattern of the revetment breakwater subjected to mainshock-aftershock sequences. Overall, geogrid reinforcement is found to be highly effective in enhancing the stability of coral sand revetment breakwaters against mainshock-aftershock sequences and holds promising applications in infrastructure construction in coral sand island and reef areas.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109190"},"PeriodicalIF":4.2,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative study of the effects of loading conditions and physical parameters on the liquefaction properties of saturated sandy soils: A DEM and experimental investigation","authors":"Yu Zhou ,&nbsp;Heping Wang ,&nbsp;Wanqing Wu ,&nbsp;Yueyang Sun ,&nbsp;Maocheng Huang ,&nbsp;Zihao Zhao ,&nbsp;Qinggong Zheng","doi":"10.1016/j.soildyn.2024.109187","DOIUrl":"10.1016/j.soildyn.2024.109187","url":null,"abstract":"<div><div>To quantify the influence of basic physical properties and cyclic loading conditions on the liquefaction properties of sandy soils, this study uses a combination of physical experiments and numerical simulations to investigate the liquefaction behavior of saturated sandy soils under undrained conditions and their relationship to physical property parameters and external loads. A numerical model with discrete elements was created based on cyclic triaxial tests. A numerical study and predictive analysis of liquefaction of common bulk samples were carried out in conjunction with a PSO-BP neural network prediction model. Using a multivariate analysis of variance and a random forest model, the complexity of the influence of physical parameters and external loads on soil liquefaction was investigated. Quantitative results indicate that particle size distribution, external loads and effective internal friction angle have a significant influence on the liquefaction of saturated sandy soils. In summary, the results of this study provide new insights into understanding the liquefaction behavior of sandy soils.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109187"},"PeriodicalIF":4.2,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Initial cyclic shear strain-based pore pressure generation model of saturated sands under cyclic stress loading","authors":"Yuan Cao ,&nbsp;Yan-Guo Zhou ,&nbsp;Akira Ishikawa ,&nbsp;Yuhei Kurimoto ,&nbsp;Yun-Min Chen","doi":"10.1016/j.soildyn.2024.109167","DOIUrl":"10.1016/j.soildyn.2024.109167","url":null,"abstract":"<div><div>The liquefaction and weakening of saturated sands under cyclic stress loading is a major concern in earthquake engineering. This study proposes a model based on initial cyclic shear strain (<em>γ</em>_c,i) to predict the excess pore pressure generation in undrained saturated sands. Here, <em>γ</em>_c,i is defined as the average cyclic shear strain prior to the significant accumulation of excess pore pressure. To calibrate and validate the model, a series of undrained stress-controlled cyclic triaxial (CTX) tests were conducted on Fujian sand with 10 % Kaolin clay (FS-10) and Silica sand no.7 with 5 % Kaolin clay (SS7-5). The FS-10 and SS7-5 specimens displayed typical flow liquefaction and cyclic mobility as they approached initial liquefaction. A critical excess pore pressure ratio (<em>r</em>_u,c) is introduced to characterize the effects of liquefaction failure modes on excess pore pressure generation. The model also incorporates reduction factors related to small-strain secant shear modulus and reference shear strain to account for variations in calculating <em>γ</em>_c,i. Ultimately, the initial cyclic shear strain-based model exhibited a strong correlation with experimental data under different confining pressures and loading cycles. In addition, it provides a critical initial cyclic shear strain for assessing soil liquefaction in engineering practices, particularly for improved ground with complex stress states.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109167"},"PeriodicalIF":4.2,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance criterion and quantification of buried continuous steel pipelines subjected to reverse fault displacement","authors":"Zilan Zhong ,&nbsp;Lingyue Xu ,&nbsp;Xudong Cheng ,&nbsp;Xiuli Du","doi":"10.1016/j.soildyn.2024.109179","DOIUrl":"10.1016/j.soildyn.2024.109179","url":null,"abstract":"<div><div>Local buckling of pipeline walls is a common failure mode for buried pipelines crossing reverse faults. The damage evolution of pipelines from initial buckling to severe failure under reverse fault displacement is closely related to soil properties, fault mechanism, and pipeline geometry. The performance-based design methodology proposed by the Pacific Earthquake Engineering Research Center has become well-recognized worldwide. However, current safety-based design codes for buried steel pipelines generally provide operable limits corresponding to the initiation of local buckling of the pipeline walls, and cannot be used to effectively assess the damage states and performance levels of pipelines. To address the local buckling of pipeline walls under fault displacement, a performance criterion is proposed based on the critical compressive strain and the change rate of pipeline compressive strain. Three performance levels corresponding to pipeline wall local buckling are identified, namely, buckling initiation, buckling development, and buckling failure. Moreover, the ductility coefficient that characterizes the nonlinear behavior of the pipeline wall prior to buckling failure is proposed in this study to quantify the damage state threshold values. Three-dimensional finite element models of the large-diameter pipeline crossing a reverse fault are developed and validated against the existing experiment study. Parametric analysis is performed to comprehensively assess the effects of pipeline burial depth, fault mechanism, and pipeline geometry on the performance of the buried steel pipeline under reverse fault displacement. Finally, the empirical equation for critical displacements between performance levels under different conditions is developed. The numerical results indicate that as the diameter-to-thickness ratio and burial depth of the pipeline increase, the structure ductility of the pipeline wall prior to buckling failure decreases. The structural ductility of the pipeline wall increases by 94.7 % as the fault dip angle increases from 30° to 90°. Moreover, the structural ductility increases when the internal pressure increases from 0 MPa to 6 MPa, but decreases as the internal pressure changes further from 6 MPa to 12 MPa.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109179"},"PeriodicalIF":4.2,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inferring apparent Newtonian viscosities of liquefied soils from physical models – Analysis using computational fluid dynamics","authors":"Soham Banerjee ,&nbsp;Yves Dubief ,&nbsp;Mandar Dewoolkar ,&nbsp;Jiarui Chen ,&nbsp;Scott Olson","doi":"10.1016/j.soildyn.2024.109170","DOIUrl":"10.1016/j.soildyn.2024.109170","url":null,"abstract":"<div><div>The behavior of liquefied soil can be simply portrayed as a viscous fluid through a single parameter viscosity. Physical modeling has often been used to estimate apparent Newtonian viscosities of liquefied soils. In these experiments, objects (e.g., spheres, cylinders, plates) are dragged through liquefied soils and the measured drag forces are analyzed using analytical, closed form solutions to determine the apparent Newtonian viscosities of the liquefied soils considered to behave as Newtonian fluid. This paper presents computational fluid dynamics (CFD)-based 2D and 3D analyses of some typical 1g and centrifuge physical models found in the literature that included dragged 3D objects (cylinder, plate, and sphere) through liquefied soils. The simulations revealed that the apparent Newtonian viscosity predicted through 3D CFD analysis simulating a sphere dragged through liquefied soil matched well with that predicted using the Stokes analytical solution, as both the CFD and analytical solution captured the 3D nature of the fluid flow around the sphere. However, the apparent Newtonian viscosities based on 2D analytical solutions applied to physical modeling results of a cylinder and a plate were found to be three to five times greater than those when 3D effects were considered in the 3D CFD simulations. The analyses showed that applying 2D assumption to 3D flow of liquefied soils could lead to unconservative estimates of apparent Newtonian viscosities as the true 3D nature of the flow of liquefied soil is not adequately captured in 2D solutions.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109170"},"PeriodicalIF":4.2,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response of an elastic half-plane with an embedded circular cavity subject to a harmonic anti-plane shear wave: A comparison of methods","authors":"Mingjuan Zhao,&nbsp;João Manuel de Oliveira Barbosa,&nbsp;Andrei V. Metrikine,&nbsp;Karel N. van Dalen","doi":"10.1016/j.soildyn.2024.109162","DOIUrl":"10.1016/j.soildyn.2024.109162","url":null,"abstract":"<div><div>In this paper, we investigate the response of a cavity embedded in an elastic half-plane (2D) subjected to a harmonic SH wave. In previous work, the method of conformal mapping and the indirect boundary element method (indirect BEM) were employed to solve the 3D wave scattering from a cylindrical tunnel embedded in a half-space. Inaccurate results were obtained particularly at high frequencies (method of conformal mapping). Therefore, in this study we focus on a comparison of the two methods with the method of images, which serves as a benchmark solution. Through a systematic evaluation, we confirm that the two methods accurately work within the complete considered ranges of the dimensionless frequency and the embedded cavity depth. This suggests that representing the waves scattered from the free surface by cylindrical waves in the method of conformal mapping is the cause of the inaccuracies at high frequency in the 3D problem; the cylindrical waves are probably not able to fully capture all wave conversions taking place at the free surface. The presented results reveal significant effects of the system parameters on the responses. The system’s response curves display nearly equally spaced resonances, which is in line with those of the 1D shear layer subject to bedrock motion, while similar response curves for the 3D case do not have this feature.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109162"},"PeriodicalIF":4.2,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of dynamic characteristics and damage mechanism of pile–net composite roadbeds in high-speed railways under seismic action","authors":"Changwei Yang ,&nbsp;Jia Luo ,&nbsp;Mao Yue ,&nbsp;Jie Fan ,&nbsp;Li Liu ,&nbsp;Lei Wang ,&nbsp;Xuanming Ding","doi":"10.1016/j.soildyn.2024.109177","DOIUrl":"10.1016/j.soildyn.2024.109177","url":null,"abstract":"<div><div>Shaking-table model experiments were conducted to study the dynamic response and damage mechanisms of pile–network composite high-speed railway foundations under seismic action. By inputting seismic waves of various types and acceleration amplitudes, the surface damage phenomena, acceleration response, and displacement response of the roadbed during vibration were analyzed. The time frequency information and energy distribution were examined using Hilbert marginal spectrum theory. Additionally, the damage mechanisms of the model were explored through transfer function analysis. The results indicated that the soil surface deformation measured using particle image velocimetry closely matched the observed macroscopic phenomena. The Peak Ground Acceleration amplification coefficients exhibited clear delamination before the structure showed signs of damage, indicating a significant energy-absorbing effect of the bedding. Spectral analysis revealed that as the vibration intensity increased, the nonlinear characteristics and damage effects of the model became more pronounced, and its ability to dissipate energy strengthened. Energy became more concentrated in the left half of the top section of the model. Moreover, as the vibration intensity increased, the self-oscillation frequency of the roadbed decreased, the stiffness diminished, the damping ratio increased, and the seismic energy dissipation improved.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109177"},"PeriodicalIF":4.2,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical simulation approach and seismic performance investigation of self-centering precast concrete frames","authors":"Yang Li ,&nbsp;Bin Zhao ,&nbsp;Feng Sun ,&nbsp;Xilin Lu","doi":"10.1016/j.soildyn.2024.109172","DOIUrl":"10.1016/j.soildyn.2024.109172","url":null,"abstract":"<div><div>Self-centering reinforced concrete frames have been extensively studied owing to their minimal residual deformation after major earthquakes. Substantial nonlinear dynamic simulations of self-centering concrete connections have been studied for subassemblies of frames. However, simulations of 3D whole concrete self-centering frame structures are limited. Therefore, in this study, a 3D concrete self-centering frame finite element model was developed based on shaking table tests of a six-story frame to investigate its seismic performance. In addition, a new method similar to the centralized plastic hinge was established to simulate the gap openings at the beam-column and column-base joints of the self-centering structure. A comparison of the simulation and test results, including the maximum roof displacements, connection gap openings, and post-tensioned (PT) strand internal force ratios, demonstrated that the model accurately simulated both local and global responses. Using this benchmark model, this study investigated the distribution of the beam-column connection gap openings on each floor of the structure, which is challenging to measure in tests. Furthermore, this study examined the effects of the initial PT forces in the beam and column strands, as well as the column strand lengths, on the seismic performance of the structure. The simulation results indicated that the gap openings at beam-column joints were uniformly distributed along the floor in the short-span direction, whereas in the long-span direction, they generally decreased with increasing height. Increasing the PT forces in the column strands and decreasing the extension story of the column strands reduced the inter-story drift on the ground floor while resulting in an increase in drift on the upper floors. In addition, reducing the strand length did not significantly decrease the self-centering capacity of the structure.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109172"},"PeriodicalIF":4.2,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}