Pub Date : 2025-01-27DOI: 10.1016/j.soildyn.2025.109247
Rui Zhao , Denghui Dai , Ning Zhang , Guangfan Wu , Mao Ye , Fanming Shen , Haijun Lu
This paper investigated the influence of soil plug effect on the vertical dynamic response of a floating pipe pile based on a three-dimensional continuum model and a fictitious soil pile model. An analytical solution for the vertical dynamic response of a floating pipe pile subjected to an upper dynamic load in the frequency domain is derived using the variable separation method. The three-dimensional characteristics of soil and the coupling dynamic interaction between the pile and the soil are considered comprehensively. Utilizing the developed solution, a parametric analysis is conducted to investigate the impact of various parameters, such as soil plug density, elastic modulus, and Poisson's ratio, on the vertical dynamic response of the pipe pile. The findings and conclusions of the parametric analysis facilitate a better understanding and prediction of the dynamic response of pile foundations across different frequency ranges.
{"title":"Vertical dynamic response of a floating pipe pile considering the soil plug effect","authors":"Rui Zhao , Denghui Dai , Ning Zhang , Guangfan Wu , Mao Ye , Fanming Shen , Haijun Lu","doi":"10.1016/j.soildyn.2025.109247","DOIUrl":"10.1016/j.soildyn.2025.109247","url":null,"abstract":"<div><div>This paper investigated the influence of soil plug effect on the vertical dynamic response of a floating pipe pile based on a three-dimensional continuum model and a fictitious soil pile model. An analytical solution for the vertical dynamic response of a floating pipe pile subjected to an upper dynamic load in the frequency domain is derived using the variable separation method. The three-dimensional characteristics of soil and the coupling dynamic interaction between the pile and the soil are considered comprehensively. Utilizing the developed solution, a parametric analysis is conducted to investigate the impact of various parameters, such as soil plug density, elastic modulus, and Poisson's ratio, on the vertical dynamic response of the pipe pile. The findings and conclusions of the parametric analysis facilitate a better understanding and prediction of the dynamic response of pile foundations across different frequency ranges.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109247"},"PeriodicalIF":4.2,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095289","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}
Pub Date : 2025-01-27DOI: 10.1016/j.soildyn.2025.109263
Linlu Zhou , Zifei Han , Lei Su , Hua-Ping Wan , Xianzhang Ling
Past seismic events have shown that caisson quay walls are susceptible to severe damage during earthquakes, underscoring the importance of assessing their seismic behavior. However, very limited studies have been conducted on the soil-structure-water interaction of the caisson-ground system during earthquakes. This study will investigate the seismic response and failure mechanism of a caisson through a centrifuge shake-table test. Specifically, the seismic response results of the backfill, the caisson, and the subsoil are discussed; an acceleration integration method for identifying permanent displacement to estimate the backfill deformation is proposed; and a phase analysis of the seismic response of the caisson-ground system is conducted. It is found that the liquefaction of the backfill results in a substantial increase in the dynamic earth pressure behind the caisson. The failure mode of the caisson is lateral movement accompanied by slight tilting and continuous rocking vibrations. The proposed acceleration integration method can effectively estimate the deformation and lateral spreading of backfill. Phase analysis results reveal the relationship between the failure of the caisson-ground system and seismic action.
{"title":"Seismic response and failure mechanism of caisson: A centrifuge shake-table investigation","authors":"Linlu Zhou , Zifei Han , Lei Su , Hua-Ping Wan , Xianzhang Ling","doi":"10.1016/j.soildyn.2025.109263","DOIUrl":"10.1016/j.soildyn.2025.109263","url":null,"abstract":"<div><div>Past seismic events have shown that caisson quay walls are susceptible to severe damage during earthquakes, underscoring the importance of assessing their seismic behavior. However, very limited studies have been conducted on the soil-structure-water interaction of the caisson-ground system during earthquakes. This study will investigate the seismic response and failure mechanism of a caisson through a centrifuge shake-table test. Specifically, the seismic response results of the backfill, the caisson, and the subsoil are discussed; an acceleration integration method for identifying permanent displacement to estimate the backfill deformation is proposed; and a phase analysis of the seismic response of the caisson-ground system is conducted. It is found that the liquefaction of the backfill results in a substantial increase in the dynamic earth pressure behind the caisson. The failure mode of the caisson is lateral movement accompanied by slight tilting and continuous rocking vibrations. The proposed acceleration integration method can effectively estimate the deformation and lateral spreading of backfill. Phase analysis results reveal the relationship between the failure of the caisson-ground system and seismic action.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109263"},"PeriodicalIF":4.2,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095298","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}
The focus of this contribution is to develop an improved 2.5-dimensional (2.5D) FE (finite element)-BE (boundary element) method for a tunnel structure-transversely isotropic saturated soil system subject to underground moving train loads. In the proposed model, the rectangular tunnel invert, the lining, and the region of interest within the soil continuum use the 2.5D FE method. The remaining region of half space is replaced with a viscous spring boundary along the lateral sides and boundary element along the bottom. The theory of acoustic propagation in saturated media is extended to include transversely isotropy, viscoelasticity and boundary elements. An existing case is calculated using the enhanced model, and the results are compared with the previous literature to validate the accuracy and reliability of the proposed method. A parametric analysis is further conducted, and the factors considered in the analysis of ground-borne vibrations induced by trains meeting in the rectangular tunnel include the soil permeability, the groundwater level, and the depth of the tunnel. Numerical comparisons show that the saturated soil above the tunnel moderates the displacement undulation caused by quasistatic axle loads of the train, but this is not the case if the load has a non-zero excitation frequency. Moving train loads with excitation produce larger excess pore water pressure amplitude than do the quasi-static loads over a wide range along the travelling direction. The effect of meeting trains depends on the running speeds of both lines in opposite directions to some extent. Other conclusions useful to practical engineers are contained in the parametric study.
{"title":"Research on the dynamic behavior of transversely isotropic saturated media due to meeting subway loads using an improved 2.5D FE-BE method","authors":"Junyan Huang , Xinjiang Wei , Zhi Ding , Weiying Xu","doi":"10.1016/j.soildyn.2025.109244","DOIUrl":"10.1016/j.soildyn.2025.109244","url":null,"abstract":"<div><div>The focus of this contribution is to develop an improved 2.5-dimensional (2.5D) FE (finite element)-BE (boundary element) method for a tunnel structure-transversely isotropic saturated soil system subject to underground moving train loads. In the proposed model, the rectangular tunnel invert, the lining, and the region of interest within the soil continuum use the 2.5D FE method. The remaining region of half space is replaced with a viscous spring boundary along the lateral sides and boundary element along the bottom. The theory of acoustic propagation in saturated media is extended to include transversely isotropy, viscoelasticity and boundary elements. An existing case is calculated using the enhanced model, and the results are compared with the previous literature to validate the accuracy and reliability of the proposed method. A parametric analysis is further conducted, and the factors considered in the analysis of ground-borne vibrations induced by trains meeting in the rectangular tunnel include the soil permeability, the groundwater level, and the depth of the tunnel. Numerical comparisons show that the saturated soil above the tunnel moderates the displacement undulation caused by quasistatic axle loads of the train, but this is not the case if the load has a non-zero excitation frequency. Moving train loads with excitation produce larger excess pore water pressure amplitude than do the quasi-static loads over a wide range along the travelling direction. The effect of meeting trains depends on the running speeds of both lines in opposite directions to some extent. Other conclusions useful to practical engineers are contained in the parametric study.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109244"},"PeriodicalIF":4.2,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095296","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}
Pub Date : 2025-01-24DOI: 10.1016/j.soildyn.2025.109241
Fan Xia, Tangdai Xia
This study introduces a novel methodology to address consolidation under long-term cyclic loading. The approach simplifies analysis by neglecting cyclic load induced fluctuations and by decomposing the cyclic load into a static load and a vibratory load without net tensile or compressive tendency over time. One-dimensional vibration consolidation tests are proposed to investigate the consolidation behavior of normally consolidated soil under vibratory loading. These tests yield a normal vibration consolidation line, which visually represents the consolidation effect of a given vibratory load on normally consolidated soil under different consolidation pressures. Based on these test results, a mathematical model is developed. This model incorporates a constitutive relationship that accounts for both the decrease in effective stress due to the structural damage caused by the vibratory load and the increase in effective stress due to the compression of the soil skeleton. The governing equation, with void ratio and effective stress as dependent variables, comprehensively describes the state change process of soil elements during vibration consolidation. Numerical solutions are then employed to analyze this process in detail.
{"title":"One-dimensional consolidation analysis of normally consolidated soft clays under vibratory loads","authors":"Fan Xia, Tangdai Xia","doi":"10.1016/j.soildyn.2025.109241","DOIUrl":"10.1016/j.soildyn.2025.109241","url":null,"abstract":"<div><div>This study introduces a novel methodology to address consolidation under long-term cyclic loading. The approach simplifies analysis by neglecting cyclic load induced fluctuations and by decomposing the cyclic load into a static load and a vibratory load without net tensile or compressive tendency over time. One-dimensional vibration consolidation tests are proposed to investigate the consolidation behavior of normally consolidated soil under vibratory loading. These tests yield a normal vibration consolidation line, which visually represents the consolidation effect of a given vibratory load on normally consolidated soil under different consolidation pressures. Based on these test results, a mathematical model is developed. This model incorporates a constitutive relationship that accounts for both the decrease in effective stress due to the structural damage caused by the vibratory load and the increase in effective stress due to the compression of the soil skeleton. The governing equation, with void ratio and effective stress as dependent variables, comprehensively describes the state change process of soil elements during vibration consolidation. Numerical solutions are then employed to analyze this process in detail.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109241"},"PeriodicalIF":4.2,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095294","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}
Pub Date : 2025-01-24DOI: 10.1016/j.soildyn.2025.109227
Wang Mingdong , Zhang Fan , Wang Wenzhe , Hou Fenghuan , Li Shuai , Wang Jingquan
Previous earthquakes reveal that the sedimentary V-shaped canyon (SVC) may result in severe damage of canyon-crossing bridges (CCBs). The seismic response of CCB is affected by various parameters, including sedimentary soil characteristics and fault rupture mechanisms. However, these influential parameters of SVC on the seismic response of CCB have not been sufficiently studied in the existing literature. Thus, this study aims to identify the most influential factor on the seismic response of bridges across SVC using parametric analysis. For this purpose, the spectral element method (SEM) is adopted to simulate the wavefield of SVC considering the fault dynamic rupture. The characteristics of ground motions in the Forward region (FR) and the Middle region (MR) are investigated. The sensitivity of ground motions recorded in SVC to four main influential factors (i.e. shear wave velocity of sedimentary soil Vs, the ratio of sedimentary soil depth to canyon depth d/D, layer sequence O, and fault-to-canyon distance Rrup) is numerically evaluated. Furthermore, the parametric analysis is performed to estimate the impact of these influential parameters on the seismic response of a CCB. The results reveal that the amplitudes of pulse-type ground motions in the illuminated side of SVC increase with the decrease of Vs. As the Vs decreases from 2300 m/s to 400 m/s, the residual deformations of four bearings increase by 293 %, 93 %, 451 %, and 292 %, respectively. When the d/D is 0.3, the velocity pulse ground motions in SVC have the largest PGVs. The base shear of the piers in the case of d/D = 0.3 increases by more than 77.3 % compared to that without considering the sedimentary soil (d/D = 0). The inverted sequence may result in larger seismic responses of bearings and piers compared to normal sequence. Rrup has the most significant effect on the seismic response of CCBs. The higher-order effect and additional plastic hinges are more noticeable when Rrup is less than or equal to 7.5 km.
{"title":"Parametric analysis of sedimentary V-shaped canyon for seismic response of canyon-crossing bridges","authors":"Wang Mingdong , Zhang Fan , Wang Wenzhe , Hou Fenghuan , Li Shuai , Wang Jingquan","doi":"10.1016/j.soildyn.2025.109227","DOIUrl":"10.1016/j.soildyn.2025.109227","url":null,"abstract":"<div><div>Previous earthquakes reveal that the sedimentary V-shaped canyon (SVC) may result in severe damage of canyon-crossing bridges (CCBs). The seismic response of CCB is affected by various parameters, including sedimentary soil characteristics and fault rupture mechanisms. However, these influential parameters of SVC on the seismic response of CCB have not been sufficiently studied in the existing literature. Thus, this study aims to identify the most influential factor on the seismic response of bridges across SVC using parametric analysis. For this purpose, the spectral element method (SEM) is adopted to simulate the wavefield of SVC considering the fault dynamic rupture. The characteristics of ground motions in the Forward region (FR) and the Middle region (MR) are investigated. The sensitivity of ground motions recorded in SVC to four main influential factors (i.e. shear wave velocity of sedimentary soil <em>V</em><sub>s</sub>, the ratio of sedimentary soil depth to canyon depth <em>d</em>/<em>D</em>, layer sequence <em>O</em>, and fault-to-canyon distance <em>R</em><sub>rup</sub>) is numerically evaluated. Furthermore, the parametric analysis is performed to estimate the impact of these influential parameters on the seismic response of a CCB. The results reveal that the amplitudes of pulse-type ground motions in the illuminated side of SVC increase with the decrease of <em>V</em><sub>s</sub>. As the <em>V</em><sub>s</sub> decreases from 2300 m/s to 400 m/s, the residual deformations of four bearings increase by 293 %, 93 %, 451 %, and 292 %, respectively. When the <em>d</em>/<em>D</em> is 0.3, the velocity pulse ground motions in SVC have the largest PGVs. The base shear of the piers in the case of <em>d</em>/<em>D</em> = 0.3 increases by more than 77.3 % compared to that without considering the sedimentary soil (<em>d</em>/<em>D</em> = 0). The inverted sequence may result in larger seismic responses of bearings and piers compared to normal sequence. <em>R</em><sub>rup</sub> has the most significant effect on the seismic response of CCBs. The higher-order effect and additional plastic hinges are more noticeable when <em>R</em><sub>rup</sub> is less than or equal to 7.5 km.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109227"},"PeriodicalIF":4.2,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094776","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}
Pub Date : 2025-01-24DOI: 10.1016/j.soildyn.2025.109246
Ling-Yu Xu , Ju-Ping Xi , Jia-Wei Jiang , Fei Cai , Ye-Jun Sun , Guo-Xing Chen
Ensuring the structural resilience of shield tunnels is critical in seismically active regions. Liquefaction induced by seismic activity poses an additional hazard to tunnel safety. The study performed seismic fragility analysis using the incremental dynamic analysis method which utilized a finite element model of a saturated porous seabed shield tunnel. The findings highlighted that different liquefaction mechanisms are observed in different types of the soil surrounding the tunnel. The thickness of the fine sand layer (FSL) surrounding the tunnel significantly affects seabed liquefaction depth and the tunnel's maximum bending moment (Mmax). The highest Mmax and damage probabilities were observed when the tunnel was entirely embedded in the FSL, whereas the smallest Mmax and lowest damage probabilities occurred when the tunnel was partially within the sand and clay. This study could also provide some insights on seismic mitigation strategies in subsea shield tunnels and the soil type influences the timing of Mmax occurrence and emphasized the critical role of seismic frequency in determining the tunnel's response.
{"title":"Seismic fragility analysis of shield tunnels in liquefiable layered deposits","authors":"Ling-Yu Xu , Ju-Ping Xi , Jia-Wei Jiang , Fei Cai , Ye-Jun Sun , Guo-Xing Chen","doi":"10.1016/j.soildyn.2025.109246","DOIUrl":"10.1016/j.soildyn.2025.109246","url":null,"abstract":"<div><div>Ensuring the structural resilience of shield tunnels is critical in seismically active regions. Liquefaction induced by seismic activity poses an additional hazard to tunnel safety. The study performed seismic fragility analysis using the incremental dynamic analysis method which utilized a finite element model of a saturated porous seabed shield tunnel. The findings highlighted that different liquefaction mechanisms are observed in different types of the soil surrounding the tunnel. The thickness of the fine sand layer (FSL) surrounding the tunnel significantly affects seabed liquefaction depth and the tunnel's maximum bending moment (<em>M</em><sub>max</sub>). The highest <em>M</em><sub>max</sub> and damage probabilities were observed when the tunnel was entirely embedded in the FSL, whereas the smallest <em>M</em><sub>max</sub> and lowest damage probabilities occurred when the tunnel was partially within the sand and clay. This study could also provide some insights on seismic mitigation strategies in subsea shield tunnels and the soil type influences the timing of <em>M</em><sub>max</sub> occurrence and emphasized the critical role of seismic frequency in determining the tunnel's response.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109246"},"PeriodicalIF":4.2,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095293","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}
Pub Date : 2025-01-23DOI: 10.1016/j.soildyn.2025.109234
Nailiang Xiang , Jian Wang , Hanxiang Xu , Xiaoxue Wu , Zixiang Wan , Xu Chen
Continuous bridges are often equipped with bonded laminated rubber bearings (B-LRBs) to accommodate the thermal movements of bridge superstructure. In addition to the shear and compression stresses typically experienced by B-LRBs, support rotations can introduce pure bending stresses, which pose a significant threat to the behavior of bearings. This study proposes a rotatable B-LRB configuration aimed at mitigating the adverse effects of support rotations. The longitudinal seismic responses of a two-span continuous bridge, equipped with conventional and rotatable B-LRBs, were analyzed and compared under mainshock-only and mainshock-aftershock earthquake scenarios. The results highlight the substantial impact of support rotations on bearing forces, with rotation-induced bending moments accounting for 40%–80 % of the total bending moment in conventional B-LRBs. This effect significantly increases the risk of bearing failure, which, however, can be effectively eliminated with the rotatable B-LRBs. The effectiveness of the rotatable bearings is particularly evident during mainshock-aftershock sequences. Premature failure of conventional B-LRBs during mainshocks exacerbates bridge damage in the subsequent aftershocks, leading to catastrophic consequences such as span unseating, which contradicts the seismic design strategy of ductile bridge piers. In contrast, the rotatable B-LRBs can prevent the failures associated with the bearings, contributing to a more predictable bridge seismic response.
{"title":"Seismic performance of continuous bridges under mainshock-aftershock-like sequences with rotatable bonded laminated rubber bearings accommodating support rotation","authors":"Nailiang Xiang , Jian Wang , Hanxiang Xu , Xiaoxue Wu , Zixiang Wan , Xu Chen","doi":"10.1016/j.soildyn.2025.109234","DOIUrl":"10.1016/j.soildyn.2025.109234","url":null,"abstract":"<div><div>Continuous bridges are often equipped with bonded laminated rubber bearings (B-LRBs) to accommodate the thermal movements of bridge superstructure. In addition to the shear and compression stresses typically experienced by B-LRBs, support rotations can introduce pure bending stresses, which pose a significant threat to the behavior of bearings. This study proposes a rotatable B-LRB configuration aimed at mitigating the adverse effects of support rotations. The longitudinal seismic responses of a two-span continuous bridge, equipped with conventional and rotatable B-LRBs, were analyzed and compared under mainshock-only and mainshock-aftershock earthquake scenarios. The results highlight the substantial impact of support rotations on bearing forces, with rotation-induced bending moments accounting for 40%–80 % of the total bending moment in conventional B-LRBs. This effect significantly increases the risk of bearing failure, which, however, can be effectively eliminated with the rotatable B-LRBs. The effectiveness of the rotatable bearings is particularly evident during mainshock-aftershock sequences. Premature failure of conventional B-LRBs during mainshocks exacerbates bridge damage in the subsequent aftershocks, leading to catastrophic consequences such as span unseating, which contradicts the seismic design strategy of ductile bridge piers. In contrast, the rotatable B-LRBs can prevent the failures associated with the bearings, contributing to a more predictable bridge seismic response.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109234"},"PeriodicalIF":4.2,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094778","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}
Pub Date : 2025-01-22DOI: 10.1016/j.soildyn.2025.109225
Yiyao Shen , M. Hesham El Naggar , Dong-Mei Zhang , Liyun Li , Xiuli Du
The selection of representative ground motion intensity measure (IM) and structural engineering demand parameter (EDP) is the crucial prerequisite for evaluating structural seismic performance within the performance-based earthquake engineering (PBEE) framework. This study focuses on this crucial step in developing the probabilistic seismic demand model for two-story and three-span subway stations exposed to transverse seismic loadings in three different ground conditions. The equivalent linearization approach is used to simulate the shear modulus degradation and the increase in damping characteristics of the soil under seismic excitation. Nonlinear fiber beam-column elements are adopted to characterize the nonlinear hysteretic degradation of the subway station structure during seismic events. A total of 21 far-field ground motions are selected from the PEER strong ground motion database. Nonlinear incremental dynamic analyses (IDAs) are conducted to evaluate the seismic response of the subway station. A suite of 23 ground motion IMs is evaluated using the criteria of correlation, efficiency, practicality, and proficiency. Then, a multi-level fuzzy evaluation method is employed to integrate these evaluation criteria and determine the optimal ground motion IMs in different ground conditions. The peak ground acceleration and sustained maximum acceleration are demonstrated to be the optimal ground motion IM candidates for shallowly buried rectangular underground structures in site classes I, II, and III, while the root-mean-square displacement and compound displacement are found to be not suitable for this purpose.
{"title":"Fuzzy-based method for seismic soil structure interaction and performance evaluation of subway stations","authors":"Yiyao Shen , M. Hesham El Naggar , Dong-Mei Zhang , Liyun Li , Xiuli Du","doi":"10.1016/j.soildyn.2025.109225","DOIUrl":"10.1016/j.soildyn.2025.109225","url":null,"abstract":"<div><div>The selection of representative ground motion intensity measure (<em>IM</em>) and structural engineering demand parameter (<em>EDP</em>) is the crucial prerequisite for evaluating structural seismic performance within the performance-based earthquake engineering (PBEE) framework. This study focuses on this crucial step in developing the probabilistic seismic demand model for two-story and three-span subway stations exposed to transverse seismic loadings in three different ground conditions. The equivalent linearization approach is used to simulate the shear modulus degradation and the increase in damping characteristics of the soil under seismic excitation. Nonlinear fiber beam-column elements are adopted to characterize the nonlinear hysteretic degradation of the subway station structure during seismic events. A total of 21 far-field ground motions are selected from the PEER strong ground motion database. Nonlinear incremental dynamic analyses (IDAs) are conducted to evaluate the seismic response of the subway station. A suite of 23 ground motion <em>IM</em>s is evaluated using the criteria of correlation, efficiency, practicality, and proficiency. Then, a multi-level fuzzy evaluation method is employed to integrate these evaluation criteria and determine the optimal ground motion <em>IM</em>s in different ground conditions. The peak ground acceleration and sustained maximum acceleration are demonstrated to be the optimal ground motion <em>IM</em> candidates for shallowly buried rectangular underground structures in site classes I, II, and III, while the root-mean-square displacement and compound displacement are found to be not suitable for this purpose.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109225"},"PeriodicalIF":4.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095197","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}
Pub Date : 2025-01-22DOI: 10.1016/j.soildyn.2025.109240
Yiming Jia , Mehrdad Sasani
Ground motion selection has become increasingly central to the assessment of earthquake resilience. The selection of ground motion records for use in nonlinear dynamic analysis significantly affects structural response. This, in turn, will impact the outcomes of earthquake resilience analysis. This paper presents a new ground motion clustering algorithm, which can be embedded in current ground motion selection methods to properly select representative ground motion records that a structure of interest will probabilistically experience. The proposed clustering-based ground motion selection method includes four main steps: 1) leveraging domain-specific knowledge to pre-select candidate ground motions; 2) using a convolutional autoencoder to learn low-dimensional underlying characteristics of candidate ground motions’ response spectra – i.e., latent features; 3) performing k-means clustering to classify the learned latent features, equivalent to cluster the response spectra of candidate ground motions; and 4) embedding the clusters in the conditional spectra-based ground motion selection. The selected ground motions can represent a given hazard level well (by matching conditional spectra) and fully describe the complete set of candidate ground motions. Three case studies for modified, pulse-type, and non-pulse-type ground motions are designed to evaluate the performance of the proposed ground motion clustering algorithm (convolutional autoencoder + k-means). Considering the limited number of pre-selected candidate ground motions in the last two case studies, the response spectra simulation and transfer learning are used to improve the stability and reproducibility of the proposed ground motion clustering algorithm. The results of the three case studies demonstrate that the convolutional autoencoder + k-means can 1) achieve 100 % accuracy in classifying ground motion response spectra, 2) correctly determine the optimal number of clusters, and 3) outperform established clustering algorithms (i.e., autoencoder + k-means, time series k-means, spectral clustering, and k-means on ground motion influence factors). Using the proposed clustering-based ground motion selection method, an application is performed to select ground motions for a structure in San Francisco, California. The developed user-friendly codes are published for practical use.
{"title":"Convolutional autoencoder-based ground motion clustering and selection","authors":"Yiming Jia , Mehrdad Sasani","doi":"10.1016/j.soildyn.2025.109240","DOIUrl":"10.1016/j.soildyn.2025.109240","url":null,"abstract":"<div><div>Ground motion selection has become increasingly central to the assessment of earthquake resilience. The selection of ground motion records for use in nonlinear dynamic analysis significantly affects structural response. This, in turn, will impact the outcomes of earthquake resilience analysis. This paper presents a new ground motion clustering algorithm, which can be embedded in current ground motion selection methods to properly select representative ground motion records that a structure of interest will probabilistically experience. The proposed clustering-based ground motion selection method includes four main steps: 1) leveraging domain-specific knowledge to pre-select candidate ground motions; 2) using a convolutional autoencoder to learn low-dimensional underlying characteristics of candidate ground motions’ response spectra – i.e., latent features; 3) performing k-means clustering to classify the learned latent features, equivalent to cluster the response spectra of candidate ground motions; and 4) embedding the clusters in the conditional spectra-based ground motion selection. The selected ground motions can represent a given hazard level well (by matching conditional spectra) and fully describe the complete set of candidate ground motions. Three case studies for modified, pulse-type, and non-pulse-type ground motions are designed to evaluate the performance of the proposed ground motion clustering algorithm (convolutional autoencoder + k-means). Considering the limited number of pre-selected candidate ground motions in the last two case studies, the response spectra simulation and transfer learning are used to improve the stability and reproducibility of the proposed ground motion clustering algorithm. The results of the three case studies demonstrate that the convolutional autoencoder + k-means can 1) achieve 100 % accuracy in classifying ground motion response spectra, 2) correctly determine the optimal number of clusters, and 3) outperform established clustering algorithms (i.e., autoencoder + k-means, time series k-means, spectral clustering, and k-means on ground motion influence factors). Using the proposed clustering-based ground motion selection method, an application is performed to select ground motions for a structure in San Francisco, California. The developed user-friendly codes are published for practical use.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109240"},"PeriodicalIF":4.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094835","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}
Pub Date : 2025-01-22DOI: 10.1016/j.soildyn.2025.109233
Zhixing Deng , Linrong Xu , Yongwei Li , Yunhao Chen , Na Su , Yuanxingzi He
To overcome the issues of limited generalization ability and unreliable prediction outcomes in subgrade cumulative deformation (SCD) models, a probabilistic prediction approach combining a data-driven neural network (DEDNN) and the Bootstrap method is introduced. Firstly, three DEDNN models are developed based on ANNs and empirical information, and the optimal DEDNN model is determined through a multi-level comprehensive assessment system. Secondly, four Bootstrap algorithms are used to modify the uncertainty in the optimal DEDNN model, namely Pairs, Residuals, Wild, and Moving Block Bootstrap, to develop and prefer the probabilistic prediction model for SCD.
Ultimately, the optimal probabilistic prediction model is employed to perform advanced prediction analysis, assessing the long-term deformation stability of the subgrade. With the help of a subgrade test section and the excitation test, a case study is carried out. The findings indicate that integrating empirical information with neural networks significantly improves the overall performance of SCD prediction models, identifying the empiricism-constrained neural network (ECNN) as the optimal DEDNN model. The prediction intervals obtained by the four Bootstrap algorithms cover the measured SCD values, and the Wild Bootstrap algorithm is determined to be the optimal Bootstrap algorithm because it has the smallest CWC value (0.5170 mm). The SCD is controlled within 4 mm at the end of the excitation test, and the prediction upper limit from the advanced probabilistic prediction is stabilized at 4.62183 mm, indicating that the long-term SCD value meets the requirements.
{"title":"Subgrade cumulative deformation probabilistic prediction method based on machine learning","authors":"Zhixing Deng , Linrong Xu , Yongwei Li , Yunhao Chen , Na Su , Yuanxingzi He","doi":"10.1016/j.soildyn.2025.109233","DOIUrl":"10.1016/j.soildyn.2025.109233","url":null,"abstract":"<div><div>To overcome the issues of limited generalization ability and unreliable prediction outcomes in subgrade cumulative deformation (SCD) models, a probabilistic prediction approach combining a data-driven neural network (DEDNN) and the Bootstrap method is introduced. Firstly, three DEDNN models are developed based on ANNs and empirical information, and the optimal DEDNN model is determined through a multi-level comprehensive assessment system. Secondly, four Bootstrap algorithms are used to modify the uncertainty in the optimal DEDNN model, namely Pairs, Residuals, Wild, and Moving Block Bootstrap, to develop and prefer the probabilistic prediction model for SCD.</div><div>Ultimately, the optimal probabilistic prediction model is employed to perform advanced prediction analysis, assessing the long-term deformation stability of the subgrade. With the help of a subgrade test section and the excitation test, a case study is carried out. The findings indicate that integrating empirical information with neural networks significantly improves the overall performance of SCD prediction models, identifying the empiricism-constrained neural network (ECNN) as the optimal DEDNN model. The prediction intervals obtained by the four Bootstrap algorithms cover the measured SCD values, and the Wild Bootstrap algorithm is determined to be the optimal Bootstrap algorithm because it has the smallest <em>CWC</em> value (0.5170 mm). The SCD is controlled within 4 mm at the end of the excitation test, and the prediction upper limit from the advanced probabilistic prediction is stabilized at 4.62183 mm, indicating that the long-term SCD value meets the requirements.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109233"},"PeriodicalIF":4.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094834","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}
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