Pub Date : 2025-02-01DOI: 10.1016/j.soildyn.2025.109269
Songlin Yue , Xu Li , Yanyu Qiu , Gan Li , Xingkai Gao , Lu Liu , Jianping Wang
Flyer plate impact tests were carried out on three water content (dry, 10 % and 30 %) coral sands using one-stage gas gun device. Based on the time course curve of particle velocity at the free surface of the specimen, the interaction between coral sand with different water content and shock wave propagation was analyzed, and the impact adiabatic relationship and equation of state of coral sand with different water content under one-dimensional strain conditions were determined. The results demonstrate that there are discernible discrepancies in the dynamic response of coral sand across varying water content conditions. The dielectric elastic wave velocity is observed to decrease with increasing water content. Conversely, the slope of the shock wave velocity-particle velocity (Ds-us) curve is seen to increase with increasing water content. The attenuation rate of shock wave propagation in coral sand is significantly affected by water content, up to 50 % in dry and 10 % water content coral sand. However, there is almost no attenuation for water content up to 30 %, and enhanced shock wave pressure may occur in the presence of reflecting boundaries.
{"title":"Investigation of the dynamic properties of coral sands with different water contents under planar impact","authors":"Songlin Yue , Xu Li , Yanyu Qiu , Gan Li , Xingkai Gao , Lu Liu , Jianping Wang","doi":"10.1016/j.soildyn.2025.109269","DOIUrl":"10.1016/j.soildyn.2025.109269","url":null,"abstract":"<div><div>Flyer plate impact tests were carried out on three water content (dry, 10 % and 30 %) coral sands using one-stage gas gun device. Based on the time course curve of particle velocity at the free surface of the specimen, the interaction between coral sand with different water content and shock wave propagation was analyzed, and the impact adiabatic relationship and equation of state of coral sand with different water content under one-dimensional strain conditions were determined. The results demonstrate that there are discernible discrepancies in the dynamic response of coral sand across varying water content conditions. The dielectric elastic wave velocity is observed to decrease with increasing water content. Conversely, the slope of the shock wave velocity-particle velocity (<em>D</em><sub>s</sub>-<em>u</em><sub>s</sub>) curve is seen to increase with increasing water content. The attenuation rate of shock wave propagation in coral sand is significantly affected by water content, up to 50 % in dry and 10 % water content coral sand. However, there is almost no attenuation for water content up to 30 %, and enhanced shock wave pressure may occur in the presence of reflecting boundaries.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109269"},"PeriodicalIF":4.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094910","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 : 2025-02-01DOI: 10.1016/j.soildyn.2025.109275
Lingyue Xu , Zilan Zhong , Zhen Cui , Xiuli Du
Geological and topographical challenges in fault zones pose significant risks to the structural integrity of buried pipelines. Previous studies have shown that continuously buried pipelines using loose sand as backfill material experience severe damage under active fault displacement. This study proposes the use of super-absorbent-polymer concrete (SAPC) as an alternative trench backfill to mitigate structural damage in buried pipelines subjected to reverse fault movement, as opposed to conventional backfill with loose sand. This study begins with the preparation of lightweight porous concrete containing large super-absorbent-polymer aggregates, followed by mechanical property testing to establish a constitutive model of SAPC. The SAPC is then employed to backfill the trench of a fault-crossing pipeline. A finite element model is developed to analyze the pipeline-SAPC trench-soil interaction and evaluate the performance of the pipeline when the trench is backfilled with SAPC. Critical parameters such as SAPC backfill length, overlying thickness, and elastic modulus are also examined for their effects on the performance of a buried pipeline. The numerical results indicate that compared with conventional backfill with loose sand, the critical reverse fault displacement of the pipeline can generally be increased by over 100 % after using SAPC as the backfill material. Optimal pipeline performance is observed when the SAPC backfill length is approximately 60 times the pipeline diameter. Besides, a thinner overlying SAPC thickness will generally enhance the performance of buried steel pipelines under reverse fault movement. Additionally, by adjusting the sand-cement ratio and SAP volume fraction, a SAPC with a higher elastic modulus can slightly improve the performance of the fault-crossing pipeline.
{"title":"Performance evaluation of revere fault-crossing buried pipeline with super-absorbent-polymer concrete as trench backfill","authors":"Lingyue Xu , Zilan Zhong , Zhen Cui , Xiuli Du","doi":"10.1016/j.soildyn.2025.109275","DOIUrl":"10.1016/j.soildyn.2025.109275","url":null,"abstract":"<div><div>Geological and topographical challenges in fault zones pose significant risks to the structural integrity of buried pipelines. Previous studies have shown that continuously buried pipelines using loose sand as backfill material experience severe damage under active fault displacement. This study proposes the use of super-absorbent-polymer concrete (SAPC) as an alternative trench backfill to mitigate structural damage in buried pipelines subjected to reverse fault movement, as opposed to conventional backfill with loose sand. This study begins with the preparation of lightweight porous concrete containing large super-absorbent-polymer aggregates, followed by mechanical property testing to establish a constitutive model of SAPC. The SAPC is then employed to backfill the trench of a fault-crossing pipeline. A finite element model is developed to analyze the pipeline-SAPC trench-soil interaction and evaluate the performance of the pipeline when the trench is backfilled with SAPC. Critical parameters such as SAPC backfill length, overlying thickness, and elastic modulus are also examined for their effects on the performance of a buried pipeline. The numerical results indicate that compared with conventional backfill with loose sand, the critical reverse fault displacement of the pipeline can generally be increased by over 100 % after using SAPC as the backfill material. Optimal pipeline performance is observed when the SAPC backfill length is approximately 60 times the pipeline diameter. Besides, a thinner overlying SAPC thickness will generally enhance the performance of buried steel pipelines under reverse fault movement. Additionally, by adjusting the sand-cement ratio and SAP volume fraction, a SAPC with a higher elastic modulus can slightly improve the performance of the fault-crossing pipeline.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109275"},"PeriodicalIF":4.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094843","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 : 2025-01-31DOI: 10.1016/j.soildyn.2025.109229
Mingnian Wang , Henghong Yang , Li Yu , Xiao Zhang
The fault dislocation induces permanent ground surface displacement, leading to severe damage to tunnels. However, there is a notable scarcity of predictive models for nonlinear surface displacement and tunnel response under dip-slip fault dislocation. Previous analytical models have oversimplified surface displacement to a constant value. To this end, first, a predictive model for assessing the mechanical response of shallowly buried tunnels under dip-slip fault dislocation is established. Then, through a mathematical statistical analysis of field-measured data, a prediction method of nonlinear dip-slip surface displacement has been developed, and the nonlinear dip-slip surface displacement is introduced into the predictive model. The predictive model incorporates nonlinear surface displacement, fault zone width, and geometric nonlinearity, thereby markedly enhancing the accuracy of the calculation results. Secondly, the prediction model undergoes validation through experimental tests and numerical simulations, revealing a maximum error of 3.7 %. In contrast, neglecting nonlinear surface displacement can result in calculation errors as high as 517.5 %. Finally, the proposed predictive model is applied to conduct a parameter analysis, such as maximum surface displacement (Δdmax), dip angle (α), and fault zone width (WF). The results shown that the maximum axial force (Nmax), maximum shear force (Vzmax), and maximum bending moment (Mzmax) of the tunnel increase with the augmentation of Δdmax. For each incremental increase of 0.2 m in Δdmax, the Nmax, Vzmax, and Mzmax exhibit an approximate increase of 22.1 %–100.3 %. The Nmax and decreases with the increasing α, whereas both the Vzmax and the Mzmax increase as α rises. With each incremental increase of 10° in α, the Nmax diminishes by approximately 16.1 %–49.2 %, while both the Vzmax and Mzmax experience an increase ranging from about 4.6 % to 19.1 %. An increase in WF results in a decrease in the Vzmax and the Mzmax exerted on the tunnel. For every increment of 10 m in WF, both the Vzmax and Mzmax decrease by approximately 15.8 %–32.3 %.
{"title":"Predictive model for assessing the nonlinear surface displacement and mechanical response of shallowly buried tunnels under dip-slip fault dislocation","authors":"Mingnian Wang , Henghong Yang , Li Yu , Xiao Zhang","doi":"10.1016/j.soildyn.2025.109229","DOIUrl":"10.1016/j.soildyn.2025.109229","url":null,"abstract":"<div><div>The fault dislocation induces permanent ground surface displacement, leading to severe damage to tunnels. However, there is a notable scarcity of predictive models for nonlinear surface displacement and tunnel response under dip-slip fault dislocation. Previous analytical models have oversimplified surface displacement to a constant value. To this end, first, a predictive model for assessing the mechanical response of shallowly buried tunnels under dip-slip fault dislocation is established. Then, through a mathematical statistical analysis of field-measured data, a prediction method of nonlinear dip-slip surface displacement has been developed, and the nonlinear dip-slip surface displacement is introduced into the predictive model. The predictive model incorporates nonlinear surface displacement, fault zone width, and geometric nonlinearity, thereby markedly enhancing the accuracy of the calculation results. Secondly, the prediction model undergoes validation through experimental tests and numerical simulations, revealing a maximum error of 3.7 %. In contrast, neglecting nonlinear surface displacement can result in calculation errors as high as 517.5 %. Finally, the proposed predictive model is applied to conduct a parameter analysis, such as maximum surface displacement (<em>Δ</em><sub>dmax</sub>), dip angle (<em>α</em>), and fault zone width (<em>W</em><sub>F</sub>). The results shown that the maximum axial force (<em>N</em><sub>max</sub>), maximum shear force (<em>V</em><sub>zmax</sub>), and maximum bending moment (<em>M</em><sub>zmax</sub>) of the tunnel increase with the augmentation of <em>Δ</em><sub>dmax</sub>. For each incremental increase of 0.2 m in <em>Δ</em><sub>dmax</sub>, the <em>N</em><sub>max</sub>, <em>V</em><sub>zmax</sub>, and <em>M</em><sub>zmax</sub> exhibit an approximate increase of 22.1 %–100.3 %. The <em>N</em><sub>max</sub> and decreases with the increasing <em>α</em>, whereas both the <em>V</em><sub>zmax</sub> and the <em>M</em><sub>zmax</sub> increase as <em>α</em> rises. With each incremental increase of 10° in <em>α</em>, the <em>N</em><sub>max</sub> diminishes by approximately 16.1 %–49.2 %, while both the <em>V</em><sub>zmax</sub> and <em>M</em><sub>zmax</sub> experience an increase ranging from about 4.6 % to 19.1 %. An increase in <em>W</em><sub>F</sub> results in a decrease in the <em>V</em><sub>zmax</sub> and the <em>M</em><sub>zmax</sub> exerted on the tunnel. For every increment of 10 m in <em>W</em><sub>F</sub>, both the <em>V</em><sub>zmax</sub> and <em>M</em><sub>zmax</sub> decrease by approximately 15.8 %–32.3 %.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109229"},"PeriodicalIF":4.2,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094842","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}
Seismic risk assessment of road networks is crucial for ensuring infrastructure resilience and enhancing informed decision-making and retrofits in earthquake-prone regions. This study aims to evaluate the seismic risk associated with retaining walls and cut slopes in three districts of northern Greece, with a particular focus on the impact of water presence. A comprehensive exposure model is developed, identifying key components along the examined road axes. Existing probabilistic seismic hazard analysis results are employed for all regions, supplemented by deterministic analyses with seismic scenarios of 475- and 955-year recurrence periods for Xanthi regional unit. Novel fragility curves for gravity retaining walls and cut slopes are proposed, while existing ones are applied for reinforced concrete retaining walls. Risk analyses are conducted for peak ground acceleration (PGA) and peak ground velocity (PGV). The probabilistic analyses outcomes reveal the critical importance of considering water presence in seismic risk assessment, identifying districts with higher level of seismic risk. Scenario-based analyses indicate that, while all elements are likely to experience minor damage under dry conditions, the presence of water leads to moderate and extensive damage for several cut slopes and retaining walls. Finally, the study emphasizes the need for targeted mitigation strategies to enhance the resilience of road infrastructure.
{"title":"Comprehensive seismic risk assessment of mountainous road networks under concurrent impact of earthquakes and water presence","authors":"Elisavet-Isavela Koutsoupaki, Dimitris Sotiriadis, Nikolaos Klimis","doi":"10.1016/j.soildyn.2025.109236","DOIUrl":"10.1016/j.soildyn.2025.109236","url":null,"abstract":"<div><div>Seismic risk assessment of road networks is crucial for ensuring infrastructure resilience and enhancing informed decision-making and retrofits in earthquake-prone regions. This study aims to evaluate the seismic risk associated with retaining walls and cut slopes in three districts of northern Greece, with a particular focus on the impact of water presence. A comprehensive exposure model is developed, identifying key components along the examined road axes. Existing probabilistic seismic hazard analysis results are employed for all regions, supplemented by deterministic analyses with seismic scenarios of 475- and 955-year recurrence periods for Xanthi regional unit. Novel fragility curves for gravity retaining walls and cut slopes are proposed, while existing ones are applied for reinforced concrete retaining walls. Risk analyses are conducted for peak ground acceleration (PGA) and peak ground velocity (PGV). The probabilistic analyses outcomes reveal the critical importance of considering water presence in seismic risk assessment, identifying districts with higher level of seismic risk. Scenario-based analyses indicate that, while all elements are likely to experience minor damage under dry conditions, the presence of water leads to moderate and extensive damage for several cut slopes and retaining walls. Finally, the study emphasizes the need for targeted mitigation strategies to enhance the resilience of road infrastructure.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109236"},"PeriodicalIF":4.2,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094844","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 : 2025-01-29DOI: 10.1016/j.soildyn.2025.109237
Jithin P. Zachariah, Ravi S. Jakka
Replacing soil with waste materials offers significant opportunities for advancing geoenvironmental practices in the construction of large-scale geostructures. The present study investigates the viability of utilizing sugarcane bagasse, a massively produced agricultural waste material, as a partial replacement for soil and its potential to control soil liquefaction. Utilization of bagasse in large geostructures not only aids in the management of a significant volume of bagasse but also facilitates the conservation of natural soil resources. Experimental investigations were conducted through a series of isotropically consolidated, stress-controlled, undrained cyclic triaxial tests. Various volumetric proportions of bagasse to sand, extending up to 50:50 (bagasse: sand), were examined to evaluate the performance of the mix under different cyclic loading conditions. The study evaluates the cyclic strength, stiffness degradation, cycle retaining index, etc., for different bagasse sand mixes across the expected cyclic stresses corresponding to Indian seismic zones 3, 4, and 5. Variation of these properties with relative density has also been studied. Results indicate that the bagasse can effectively be utilized as a geomaterial to partially replace the soil in large proportions ranging from 19 % to 41 % without compromising the initial cyclic strength of the natural soil. Notably, at an optimal content of 30 %, the bagasse sand mix exhibits higher resistance to the accumulation of excess pore water pressure, maximizing its liquefaction resistance. Furthermore, the utilization of bagasse as a partial replacement for soil increased the cyclic degradation index within the suggested range of bagasse content.
{"title":"Cyclic behavior and liquefaction resistance of sand with partial bagasse replacement","authors":"Jithin P. Zachariah, Ravi S. Jakka","doi":"10.1016/j.soildyn.2025.109237","DOIUrl":"10.1016/j.soildyn.2025.109237","url":null,"abstract":"<div><div>Replacing soil with waste materials offers significant opportunities for advancing geoenvironmental practices in the construction of large-scale geostructures. The present study investigates the viability of utilizing sugarcane bagasse, a massively produced agricultural waste material, as a partial replacement for soil and its potential to control soil liquefaction. Utilization of bagasse in large geostructures not only aids in the management of a significant volume of bagasse but also facilitates the conservation of natural soil resources. Experimental investigations were conducted through a series of isotropically consolidated, stress-controlled, undrained cyclic triaxial tests. Various volumetric proportions of bagasse to sand, extending up to 50:50 (bagasse: sand), were examined to evaluate the performance of the mix under different cyclic loading conditions. The study evaluates the cyclic strength, stiffness degradation, cycle retaining index, etc., for different bagasse sand mixes across the expected cyclic stresses corresponding to Indian seismic zones 3, 4, and 5. Variation of these properties with relative density has also been studied. Results indicate that the bagasse can effectively be utilized as a geomaterial to partially replace the soil in large proportions ranging from 19 % to 41 % without compromising the initial cyclic strength of the natural soil. Notably, at an optimal content of 30 %, the bagasse sand mix exhibits higher resistance to the accumulation of excess pore water pressure, maximizing its liquefaction resistance. Furthermore, the utilization of bagasse as a partial replacement for soil increased the cyclic degradation index within the suggested range of bagasse content.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109237"},"PeriodicalIF":4.2,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095292","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 : 2025-01-29DOI: 10.1016/j.soildyn.2025.109214
Tuba Gurbuz , Abdullah Cengiz
On February 6, 2023, two very destructive earthquakes by 9 h apart, Mw 7.8 Pazarcık and Mw 7.7 Elbistan (Kahramanmaraş Earthquakes), struck southeastern Turkey, causing more than 50 thousand loss of lives, 40 thousand collapsed and more than half a million damaged buildings. Our research team conducted a site investigation at the earthquake-hit area and this paper presents common structural damages observed at site. Seismological characteristics of the earthquakes was presented and spectral accelerations formed by using strong ground motion records were shared with design spectrums by Turkish Seismic Design Code 2018 (TSDC2018). In certain locations, response acceleration spectra of the ground motion exceeded elastic design spectrum values in the current TSDC2018 (sometimes exceeded maximum earthquake level DD1). Some new buildings designed in accordance with TSDC2018 were hit by a greater seismic load and heavily damaged/collapsed during Kahramanmaraş Earthquakes. However, most of new structures, which were designed and constructed to ensure high ductility and owing to their existing reserve capacities, were able to survive the earthquakes and prevented loss of lives even though, many of them were heavily damaged. Nonlinear time history analysis was conducted to determine seismic performance of six storey buildings, which were designed by TSDC2018 considering both design (DD2) and maximum (DD1) earthquake levels, with return periods of 475 and 2475 years. A construction cost comparison was also conducted for RC buildings, which were designed by two (DD2, DD1) earthquake levels, respectively. As a result of the conclusions made throughout the study, the current seismic design procedure for regular RC buildings located in high risk seismic regions should be reevaluated to enhance their seismic resilience.
{"title":"Structural damages during the February 06, 2023 Kahramanmaraş Earthquakes in Turkey","authors":"Tuba Gurbuz , Abdullah Cengiz","doi":"10.1016/j.soildyn.2025.109214","DOIUrl":"10.1016/j.soildyn.2025.109214","url":null,"abstract":"<div><div>On February 6, 2023, two very destructive earthquakes by 9 h apart, Mw 7.8 Pazarcık and Mw 7.7 Elbistan (Kahramanmaraş Earthquakes), struck southeastern Turkey, causing more than 50 thousand loss of lives, 40 thousand collapsed and more than half a million damaged buildings. Our research team conducted a site investigation at the earthquake-hit area and this paper presents common structural damages observed at site. Seismological characteristics of the earthquakes was presented and spectral accelerations formed by using strong ground motion records were shared with design spectrums by Turkish Seismic Design Code 2018 (TSDC2018). In certain locations, response acceleration spectra of the ground motion exceeded elastic design spectrum values in the current TSDC2018 (sometimes exceeded maximum earthquake level DD1). Some new buildings designed in accordance with TSDC2018 were hit by a greater seismic load and heavily damaged/collapsed during Kahramanmaraş Earthquakes. However, most of new structures, which were designed and constructed to ensure high ductility and owing to their existing reserve capacities, were able to survive the earthquakes and prevented loss of lives even though, many of them were heavily damaged. Nonlinear time history analysis was conducted to determine seismic performance of six storey buildings, which were designed by TSDC2018 considering both design (DD2) and maximum (DD1) earthquake levels, with return periods of 475 and 2475 years. A construction cost comparison was also conducted for RC buildings, which were designed by two (DD2, DD1) earthquake levels, respectively. As a result of the conclusions made throughout the study, the current seismic design procedure for regular RC buildings located in high risk seismic regions should be reevaluated to enhance their seismic resilience.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109214"},"PeriodicalIF":4.2,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095290","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 : 2025-01-28DOI: 10.1016/j.soildyn.2025.109221
Jianbo Li , Zhewen Hu
Nuclear facility sites built on soft deposits often adopt a combined piled cushion raft foundation (CPCRF) to enhance bearing capacity. However, separation and slip at the raft–bottom interface is inevitable in refined seismic simulations of weakly anchored nuclear island buildings (NIBs). Multiple factors related to both the structure and foundation influence the interface behavior. To address this, a structure–interface–soil nonlinear interaction model was developed, incorporating interfacial discontinuity characteristics, tri-directional wave inputs, and a stable semi-unbounded condition. The validity of the wave–field simulation method and the interface model were confirmed through theoretical comparisons. Using the AP1000 NIB at a specific CPCRF site as an example, the practicability of the model was validated, and key behavioral patterns were identified. In the static-seismic process, correlations between interface behavior, pile damage, and structural vibration were quantitatively elucidated. When seismic intensity exceeded design limits, the minimum instantaneous grounding ratio decreased rapidly. Structural vertical acceleration nearly doubled, and the frequency band of peak horizontal vibration shifted to higher frequencies. Interface behavior strongly correlated with slip stability and pile body damage. These findings indicate that interfacial discontinuities at the raft's bottom pose safety risks warranting further investigation.
{"title":"Systematic seismic simulation for nuclear island buildings in CPCRF site: Insights into interfacial discontinuity","authors":"Jianbo Li , Zhewen Hu","doi":"10.1016/j.soildyn.2025.109221","DOIUrl":"10.1016/j.soildyn.2025.109221","url":null,"abstract":"<div><div>Nuclear facility sites built on soft deposits often adopt a combined piled cushion raft foundation (CPCRF) to enhance bearing capacity. However, separation and slip at the raft–bottom interface is inevitable in refined seismic simulations of weakly anchored nuclear island buildings (NIBs). Multiple factors related to both the structure and foundation influence the interface behavior. To address this, a structure–interface–soil nonlinear interaction model was developed, incorporating interfacial discontinuity characteristics, tri-directional wave inputs, and a stable semi-unbounded condition. The validity of the wave–field simulation method and the interface model were confirmed through theoretical comparisons. Using the AP1000 NIB at a specific CPCRF site as an example, the practicability of the model was validated, and key behavioral patterns were identified. In the static-seismic process, correlations between interface behavior, pile damage, and structural vibration were quantitatively elucidated. When seismic intensity exceeded design limits, the minimum instantaneous grounding ratio decreased rapidly. Structural vertical acceleration nearly doubled, and the frequency band of peak horizontal vibration shifted to higher frequencies. Interface behavior strongly correlated with slip stability and pile body damage. These findings indicate that interfacial discontinuities at the raft's bottom pose safety risks warranting further investigation.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109221"},"PeriodicalIF":4.2,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094845","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 : 2025-01-28DOI: 10.1016/j.soildyn.2025.109272
Lang Wang , Zhaowei Chen , Jiangshen Chen
Rack railways are essential for mountainous railway transportation because of their ability to navigate steep slopes. However, in the tectonically active southwestern mountainous region of China, which is characterized by extensive fault zones, the behavior of rack systems on bridges under seismic loads has not been thoroughly studied. Here, this gap is addressed by developing a dynamic model of the vehicle–track–bridge system under seismic loading via train–track–bridge interaction theory. The mechanical properties of rack systems with both rigid and elastic connection methods are examined in this study, with a focus on key parameters such as rack tensile stress, shear stress, lateral torque, and bolt shear stress under varying dynamic loads. Rigid connections exhibit greater stiffness, leading to stress concentrations under coupled seismic and vehicle loads. This stiffness results in stress concentrations near bridge bearings, in which the maximum tensile stress, shear stress, and lateral torque reach 242 MPa, 226 MPa, and 2380 N m, respectively. Moreover, the maximum bolt shear stress reached 222 MPa, surpassing the shear and bending strength thresholds, further indicating a risk of localized structural failure. Conversely, elastic connections, with their buffering effects, effectively reduce stress concentrations. The maximum tensile stress, shear stress, lateral torque, and bolt shear stress were reduced to 68 MPa, 147 MPa, 1630 N m, and 120 MPa, respectively, which are all within safety limits. These findings demonstrate that elastic connections enhance the stability and safety of rack railway systems on bridges under seismic conditions. The aim of this study is to provide a theoretical basis for the design and safety assessment of rack railways on bridges in mountainous regions.
{"title":"Mechanical properties and safety analysis of rack railways under seismic loads with different connection methods","authors":"Lang Wang , Zhaowei Chen , Jiangshen Chen","doi":"10.1016/j.soildyn.2025.109272","DOIUrl":"10.1016/j.soildyn.2025.109272","url":null,"abstract":"<div><div>Rack railways are essential for mountainous railway transportation because of their ability to navigate steep slopes. However, in the tectonically active southwestern mountainous region of China, which is characterized by extensive fault zones, the behavior of rack systems on bridges under seismic loads has not been thoroughly studied. Here, this gap is addressed by developing a dynamic model of the vehicle–track–bridge system under seismic loading via train–track–bridge interaction theory. The mechanical properties of rack systems with both rigid and elastic connection methods are examined in this study, with a focus on key parameters such as rack tensile stress, shear stress, lateral torque, and bolt shear stress under varying dynamic loads. Rigid connections exhibit greater stiffness, leading to stress concentrations under coupled seismic and vehicle loads. This stiffness results in stress concentrations near bridge bearings, in which the maximum tensile stress, shear stress, and lateral torque reach 242 MPa, 226 MPa, and 2380 N m, respectively. Moreover, the maximum bolt shear stress reached 222 MPa, surpassing the shear and bending strength thresholds, further indicating a risk of localized structural failure. Conversely, elastic connections, with their buffering effects, effectively reduce stress concentrations. The maximum tensile stress, shear stress, lateral torque, and bolt shear stress were reduced to 68 MPa, 147 MPa, 1630 N m, and 120 MPa, respectively, which are all within safety limits. These findings demonstrate that elastic connections enhance the stability and safety of rack railway systems on bridges under seismic conditions. The aim of this study is to provide a theoretical basis for the design and safety assessment of rack railways on bridges in mountainous regions.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109272"},"PeriodicalIF":4.2,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095291","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.2025.109248
Zhenglong Zhou, Zhengyang Zhang, Ziyi Ye, Guanlan Xu, Yan Zhang, Guoxing Chen, Jiawei Jiang
Existing research on soil liquefaction probability discrimination usually only considers the inherent variability of soil parameters, neglecting the impact of stratigraphic variability. To address this, the study couples an embedded Markov chain model with a conditional random field model to simulate the spatial variability of both stratigraphy and soil parameters simultaneously. The Yangtze River Delta region in China, due to its unique geographical location, is highly sensitive to secondary disasters such as soil liquefaction triggered by earthquakes. This study uses measured borehole data from the coastal area of the Yangtze River estuary in the region, employing the embedded Markov chain model to simulate stratigraphic structural variability and the conditional random field model to simulate soil dynamic parameters. The simulation results are used to assess the liquefaction probability of seabed sites under seismic conditions, providing a scientific basis for the site selection and safety evaluation of marine engineering projects. The research indicates that considering the spatial variability of both stratigraphy and soil parameters is crucial for accurately assessing liquefaction potential.
{"title":"A method for determining the probability of seabed liquefaction considering stratigraphic structure and variations in soil dynamic characteristics","authors":"Zhenglong Zhou, Zhengyang Zhang, Ziyi Ye, Guanlan Xu, Yan Zhang, Guoxing Chen, Jiawei Jiang","doi":"10.1016/j.soildyn.2025.109248","DOIUrl":"10.1016/j.soildyn.2025.109248","url":null,"abstract":"<div><div>Existing research on soil liquefaction probability discrimination usually only considers the inherent variability of soil parameters, neglecting the impact of stratigraphic variability. To address this, the study couples an embedded Markov chain model with a conditional random field model to simulate the spatial variability of both stratigraphy and soil parameters simultaneously. The Yangtze River Delta region in China, due to its unique geographical location, is highly sensitive to secondary disasters such as soil liquefaction triggered by earthquakes. This study uses measured borehole data from the coastal area of the Yangtze River estuary in the region, employing the embedded Markov chain model to simulate stratigraphic structural variability and the conditional random field model to simulate soil dynamic parameters. The simulation results are used to assess the liquefaction probability of seabed sites under seismic conditions, providing a scientific basis for the site selection and safety evaluation of marine engineering projects. The research indicates that considering the spatial variability of both stratigraphy and soil parameters is crucial for accurately assessing liquefaction potential.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109248"},"PeriodicalIF":4.2,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094846","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.2025.109249
Zhiyi Liu , Deqing Gan , Haikuan Sun , Zhenlin Xue , Youzhi Zhang
Cemented tailings backfill (CTB) is a way to make full use of tailings, but its dynamic mechanical and damage characteristics under water bearing environment are still not clear. In this paper, CTB was completely immersed with different immersion time (5 d, 10 d, 20 d, 30 d) under different initial immersion age (3 d, 7 d, 14 d, 28 d). The dynamic compression test under different impact velocity (3.0 m s−1, 4.5 m s−1, 6.0 m s−1, 7.5 m s−1) was carried out by using split Hopkinson pressure bar. The mechanical properties and damage evolution law of CTB were analyzed by low field nuclear magnetic resonance and SEM. Results show that the post-peak stage characteristics of the stress-strain curve of water-immersed CTB under impact load is divided into four types, which are type I “strain rebound”, type II “stress drop”, type III “post-peak plasticity”, and type IV “post-peak ductility”. Water immersion effect mainly increases the peak damage degree of CTB and the proportion of the damage before the peak strain to the total damage. Under impact load, water immersion effect reduces the bearing capacity of the gel matrix of CTB and promotes the dislocation of tailings and the expansion of the original crack surface. However, the free water in the pores do not have enough time to flow to the tip of the original crack, which hinders the crack growth. Based on Weibull distribution and Kelvin model, the dynamic aging damage model of water-immersed CTB is constructed, which provides a theoretical basis for analyzing the failure mechanism of CTB under water immersion. Besides, it is suggested that reducing the immersion time of CTB in water is the key factor to improve the stability of CTB.
{"title":"Dynamic impact performance of cemented tailings backfill in a water-bearing environment: Coupling effects and damage characteristics","authors":"Zhiyi Liu , Deqing Gan , Haikuan Sun , Zhenlin Xue , Youzhi Zhang","doi":"10.1016/j.soildyn.2025.109249","DOIUrl":"10.1016/j.soildyn.2025.109249","url":null,"abstract":"<div><div>Cemented tailings backfill (CTB) is a way to make full use of tailings, but its dynamic mechanical and damage characteristics under water bearing environment are still not clear. In this paper, CTB was completely immersed with different immersion time (5 d, 10 d, 20 d, 30 d) under different initial immersion age (3 d, 7 d, 14 d, 28 d). The dynamic compression test under different impact velocity (3.0 m s<sup>−1</sup>, 4.5 m s<sup>−1</sup>, 6.0 m s<sup>−1</sup>, 7.5 m s<sup>−1</sup>) was carried out by using split Hopkinson pressure bar. The mechanical properties and damage evolution law of CTB were analyzed by low field nuclear magnetic resonance and SEM. Results show that the post-peak stage characteristics of the stress-strain curve of water-immersed CTB under impact load is divided into four types, which are type I “strain rebound”, type II “stress drop”, type III “post-peak plasticity”, and type IV “post-peak ductility”. Water immersion effect mainly increases the peak damage degree of CTB and the proportion of the damage before the peak strain to the total damage. Under impact load, water immersion effect reduces the bearing capacity of the gel matrix of CTB and promotes the dislocation of tailings and the expansion of the original crack surface. However, the free water in the pores do not have enough time to flow to the tip of the original crack, which hinders the crack growth. Based on Weibull distribution and Kelvin model, the dynamic aging damage model of water-immersed CTB is constructed, which provides a theoretical basis for analyzing the failure mechanism of CTB under water immersion. Besides, it is suggested that reducing the immersion time of CTB in water is the key factor to improve the stability of CTB.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"191 ","pages":"Article 109249"},"PeriodicalIF":4.2,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143095295","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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