Pub Date : 2025-01-03DOI: 10.1016/j.soildyn.2024.109183
Zhong-Liang Zhang, Zhen-Dong Cui, Min-Zhe Xu
Soft clay is extensively distributed in the Yangtze River Delta of China. Many seismic events indicate that underground structures buried in soft soil may suffer severe damage from earthquakes. In this study, a series of bidirectional dynamic cyclic triaxial tests were conducted to investigate the dynamic behavior of soft clay, considering different confining pressures and consolidation stress ratios. A simplified equivalent seismic loading method based on the strain failure criterion was proposed. The obtained equivalent amplitude of soft clay calculating by the critical cyclic stress ratio is averagely 1.58 times that of the sand liquefaction method. Under equivalent seismic cyclic loading, the dynamic shear strain and excess pore pressure of soft clay increases with the increase of confining pressure. The relationship between the maximum excess pore pressure and the corresponding shear strain can be expressed by a hyperbolic function. Due to the weakening effect of seismic loading, the shear modulus decreases as the shear strain increases, with a sudden reduction of up to 45 %. The shear modulus and damping ratio increase with the increase of confining pressure and consolidation stress ratio. The research results may provide some valuable insights into the seismic design practices in soft clay areas.
{"title":"Experimental investigation of the undrained dynamic behavior of soft clay under equivalent earthquake loadings","authors":"Zhong-Liang Zhang, Zhen-Dong Cui, Min-Zhe Xu","doi":"10.1016/j.soildyn.2024.109183","DOIUrl":"10.1016/j.soildyn.2024.109183","url":null,"abstract":"<div><div>Soft clay is extensively distributed in the Yangtze River Delta of China. Many seismic events indicate that underground structures buried in soft soil may suffer severe damage from earthquakes. In this study, a series of bidirectional dynamic cyclic triaxial tests were conducted to investigate the dynamic behavior of soft clay, considering different confining pressures and consolidation stress ratios. A simplified equivalent seismic loading method based on the strain failure criterion was proposed. The obtained equivalent amplitude of soft clay calculating by the critical cyclic stress ratio is averagely 1.58 times that of the sand liquefaction method. Under equivalent seismic cyclic loading, the dynamic shear strain and excess pore pressure of soft clay increases with the increase of confining pressure. The relationship between the maximum excess pore pressure and the corresponding shear strain can be expressed by a hyperbolic function. Due to the weakening effect of seismic loading, the shear modulus decreases as the shear strain increases, with a sudden reduction of up to 45 %. The shear modulus and damping ratio increase with the increase of confining pressure and consolidation stress ratio. The research results may provide some valuable insights into the seismic design practices in soft clay areas.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109183"},"PeriodicalIF":4.2,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102030","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 : 2025-01-03DOI: 10.1016/j.soildyn.2024.109207
Nan Yan , Zengming Hao , Xiaoyu Bai , Lin Cui , Jichao Yin , Chao Liu , Yamei Zhang
The Qingdao region in China is a typical coastal city characterized by “upper soil lower rock” binary composite formations, with a weak upper layer of sandy silty clay that cannot provide sufficient bearing capacity. Through conducting vertical compression static load tests, the vertical bearing characteristics of the socketed moderately weathered rock bored piles were revealed. Combined with theoretical analysis and numerical simulation methods, the applicability of different theoretical models in predicting the vertical compressive ultimate bearing capacity of single piles was evaluated. Further, the influencing factors of bearing performance were analyzed. The research results show that the load-displacement (Q-s) curves of the three test piles were of the gradual type, and the rock-socketed piles exhibit the characteristics of friction end-bearing piles to varying degrees. The accuracy of various theoretical models in predicting the vertical compressive ultimate bearing capacity of single piles was as follows, in descending order: adjusted hyperbolic model, hyperbolic model, exponential curve model, pile material strength calculation formula. Under similar engineering geological conditions, the reasonable ranges of parameters in the influencing factors of the rock-socketed piles were as follows: length-to-diameter ratio of 12≤L/d ≤ 15, rock-socketed ratio of 2≤hr/d ≤ 3, pile-rock elastic modulus ratio of 10≤Ep/Er ≤ 30, and friction coefficient of 0.4≤μ≤0.6.
{"title":"Load-bearing characteristics and optimization design for rock-socketed bored piles in sandy silty clay in coastal areas","authors":"Nan Yan , Zengming Hao , Xiaoyu Bai , Lin Cui , Jichao Yin , Chao Liu , Yamei Zhang","doi":"10.1016/j.soildyn.2024.109207","DOIUrl":"10.1016/j.soildyn.2024.109207","url":null,"abstract":"<div><div>The Qingdao region in China is a typical coastal city characterized by “upper soil lower rock” binary composite formations, with a weak upper layer of sandy silty clay that cannot provide sufficient bearing capacity. Through conducting vertical compression static load tests, the vertical bearing characteristics of the socketed moderately weathered rock bored piles were revealed. Combined with theoretical analysis and numerical simulation methods, the applicability of different theoretical models in predicting the vertical compressive ultimate bearing capacity of single piles was evaluated. Further, the influencing factors of bearing performance were analyzed. The research results show that the load-displacement (<em>Q</em>-<em>s</em>) curves of the three test piles were of the gradual type, and the rock-socketed piles exhibit the characteristics of friction end-bearing piles to varying degrees. The accuracy of various theoretical models in predicting the vertical compressive ultimate bearing capacity of single piles was as follows, in descending order: adjusted hyperbolic model, hyperbolic model, exponential curve model, pile material strength calculation formula. Under similar engineering geological conditions, the reasonable ranges of parameters in the influencing factors of the rock-socketed piles were as follows: length-to-diameter ratio of 12≤<em>L</em>/<em>d</em> ≤ 15, rock-socketed ratio of 2≤<em>h</em><sub>r</sub>/<em>d</em> ≤ 3, pile-rock elastic modulus ratio of 10≤<em>E</em><sub>p</sub>/<em>E</em><sub>r</sub> ≤ 30, and friction coefficient of 0.4≤<em>μ</em>≤0.6.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109207"},"PeriodicalIF":4.2,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102031","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 objective of this investigation is to develop the damage-based energy factor () for seismic demand evaluation of Reinforced Concrete (RC) and steel structures under probable future ground motions regarding the energy-balance theorem and use in the Performance-Based Plastic Design (PBPD) procedure. Before this, the energy factor was determined considering different ductility levels, where the procedure could be extended at constant specific damage levels in damage-based design theory to consider the influence of the hysteresis energy, frequency content, ground motions amplitude, and duration for design purposes. Hence, the popular Park-Ang damage index was employed as a damage model to obtain energy factor under 400 far-fault ground motion records by investigating the influence of structural and earthquake properties on it, including period of vibration, damage level, ultimate ductility ratio, stiffness hardening, structural deterioration, factor, soil class type, magnitude (Mw), and source-to-site distance. Due to the influence of ground motion characteristics by using statistical analysis, the ratio is employed to determine the energy factor, which depends on soil class type, magnitude, fault mechanism, and source-to-site distance. Also, a simple equation based on nonlinear regression analysis among data is suggested to estimate the energy factor based on influential structural and earthquake characteristics, and its error is demonstrated by the two concepts of bias and standard deviation. Finally, three empirical structures validated by numerical modeling, consisting of a full-scale RC bridge pier, a full-scale four-story RC building, and the three-story steel frame, are considered to validate the accuracy of the proposed method and equation. Statistical results illustrate that the difference between estimated displacements and obtained ones from direct time history analysis is not higher than 20 %, especially compared to the existing damage-based coefficient method.
{"title":"The development of damage-based energy factor under far-fault ground motions for the seismic demand evaluation of structural systems in energy-balance theorem","authors":"Pouya Amirchoupani, Rasool Nodeh Farahani, Gholamreza Abdollahzadeh","doi":"10.1016/j.soildyn.2024.109200","DOIUrl":"10.1016/j.soildyn.2024.109200","url":null,"abstract":"<div><div>The objective of this investigation is to develop the damage-based energy factor (<span><math><mrow><mi>γ</mi></mrow></math></span>) for seismic demand evaluation of Reinforced Concrete (RC) and steel structures under probable future ground motions regarding the energy-balance theorem and use in the Performance-Based Plastic Design (PBPD) procedure. Before this, the energy factor was determined considering different ductility levels, where the procedure could be extended at constant specific damage levels in damage-based design theory to consider the influence of the hysteresis energy, frequency content, ground motions amplitude, and duration for design purposes. Hence, the popular Park-Ang damage index was employed as a damage model to obtain energy factor under 400 far-fault ground motion records by investigating the influence of structural and earthquake properties on it, including period of vibration, damage level, ultimate ductility ratio, stiffness hardening, structural deterioration, <span><math><mrow><mi>β</mi></mrow></math></span> factor, soil class type, magnitude (M<sub>w</sub>), and source-to-site distance. Due to the influence of ground motion characteristics by using statistical analysis, the <span><math><mrow><msub><mi>A</mi><mi>p</mi></msub><mo>/</mo><msub><mi>V</mi><mi>p</mi></msub></mrow></math></span> ratio is employed to determine the energy factor, which depends on soil class type, magnitude, fault mechanism, and source-to-site distance. Also, a simple equation based on nonlinear regression analysis among data is suggested to estimate the energy factor based on influential structural and earthquake characteristics, and its error is demonstrated by the two concepts of bias and standard deviation. Finally, three empirical structures validated by numerical modeling, consisting of a full-scale RC bridge pier, a full-scale four-story RC building, and the three-story steel frame, are considered to validate the accuracy of the proposed method and equation. Statistical results illustrate that the difference between estimated displacements and obtained ones from direct time history analysis is not higher than 20 %, especially compared to the existing damage-based coefficient method.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109200"},"PeriodicalIF":4.2,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102494","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 : 2025-01-02DOI: 10.1016/j.soildyn.2024.109194
Hao Wu, Suyang Qiao, Ying Zhou
The heat-absorbing tower is a novel tall power generation structure, with limited global application to date. Unlike traditional towers, which primarily serve as platforms for deploying large mass absorbers to capture reflected sunlight for electricity generation, the heat-absorbing and air-cooling (HAAC) tower is an innovative concept. It features an internally hollow design with strategically placed air inlets and outlets, and a substantial mass positioned at the top. This novel configuration not only supports absorber deployment for sunlight capture but also integrates indirect air-cooling capabilities, thereby achieving multifunctionality in infrastructure. To investigate the seismic performance of the proposed HAAC tower, assess its vulnerability, and support safety enhancement in sustainable and multifunctional infrastructure, a seismic fragility evaluation method based on incremental dynamic analysis (IDA) was adopted. A validated finite element model in ABAQUS, correlated with scaled shaking table tests, assessed 11 earthquake records across 22 intensity levels, resulting in over 242 case studies. Five intensity measures (IMs) were used: PGA, Sa(T1,4 %), PGV, S∗ (a modified Sa accounting for post-yield period elongation), and S12 – (spectral acceleration for the first two modes). Two damage measures (DMs): θmax (maximum inter-story drift) and θtop (top drift), were employed in IDA and fragility analysis. Results indicate that S∗ exhibits the strongest correlation to DMs, followed by PGV, PGA, S12 and Sa(T1,4 %). Using θmax as the DM parameter reveals higher structural demands, indicating an increased likelihood of reaching critical limit states compared to θtop. The findings suggest that the proposed HAAC tower exhibits good seismic performance, supporting the enhancement of safety and the development of multifunctional infrastructure within sustainable infrastructure.
{"title":"Seismic performance evaluation of a tall tower structure with integrated heat-absorbing and air-cooling capabilities: IDA based seismic fragility analysis","authors":"Hao Wu, Suyang Qiao, Ying Zhou","doi":"10.1016/j.soildyn.2024.109194","DOIUrl":"10.1016/j.soildyn.2024.109194","url":null,"abstract":"<div><div>The heat-absorbing tower is a novel tall power generation structure, with limited global application to date. Unlike traditional towers, which primarily serve as platforms for deploying large mass absorbers to capture reflected sunlight for electricity generation, the heat-absorbing and air-cooling (HAAC) tower is an innovative concept. It features an internally hollow design with strategically placed air inlets and outlets, and a substantial mass positioned at the top. This novel configuration not only supports absorber deployment for sunlight capture but also integrates indirect air-cooling capabilities, thereby achieving multifunctionality in infrastructure. To investigate the seismic performance of the proposed HAAC tower, assess its vulnerability, and support safety enhancement in sustainable and multifunctional infrastructure, a seismic fragility evaluation method based on incremental dynamic analysis (IDA) was adopted. A validated finite element model in ABAQUS, correlated with scaled shaking table tests, assessed 11 earthquake records across 22 intensity levels, resulting in over 242 case studies. Five intensity measures (IMs) were used: <em>PGA</em>, <em>S</em><sub><em>a</em></sub>(<em>T</em><sub>1</sub>,4 %), <em>PGV</em>, <em>S∗</em> (a modified <em>S</em><sub><em>a</em></sub> accounting for post-yield period elongation), and <em>S</em><sub>12</sub> – (spectral acceleration for the first two modes). Two damage measures (DMs): <em>θ</em><sub>max</sub> (maximum inter-story drift) and <em>θ</em><sub>top</sub> (top drift), were employed in IDA and fragility analysis. Results indicate that <em>S</em>∗ exhibits the strongest correlation to DMs, followed by <em>PGV</em>, <em>PGA</em>, <em>S</em><sub>12</sub> and <em>S</em><sub><em>a</em></sub>(<em>T</em><sub>1</sub>,4 %). Using <em>θ</em><sub>max</sub> as the DM parameter reveals higher structural demands, indicating an increased likelihood of reaching critical limit states compared to <em>θ</em><sub>top</sub>. The findings suggest that the proposed HAAC tower exhibits good seismic performance, supporting the enhancement of safety and the development of multifunctional infrastructure within sustainable infrastructure.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109194"},"PeriodicalIF":4.2,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102025","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 : 2025-01-02DOI: 10.1016/j.soildyn.2024.109198
You Qin , Hui Long , Qi Wu , Wei-Jia Ma , Guo-Xing Chen , Hai-Yang Zhuang
Seismic events and wave action can induce volumetric strain (εv) accumulation in saturated sandy soils, leading to damage to the ground surface and structures. A quantifiable relationship exists between the generation of εv in sandy soils under drained conditions and the development of pore water pressures under undrained conditions. In this study, the impact of relative density (Dr), cyclic stress path, and stress level on the characteristics of volumetric strain (εv) generation in saturated coral sands (SCS) was evaluated through drained tests employing various cyclic stress paths. The test findings demonstrate that the rate of εv accumulation in SCS is notably affected by the cyclic stress path. The rise in peak volumetric strain (εvp) in SCS, as a function of the number of cycles, conforms to the arctangent function model. The unit cyclic stress ratio (USR) was employed as an indicator of complex cyclic loading levels. It was determined that coefficient (εvp)u is positively correlated with USR at a specific Dr. At the same Dr, coefficient CN1 exhibits a positive correlation with USR, while coefficient CN2 displays a negative correlation with USR, following a power-law relationship. Irrespective of cyclic loading conditions, εvp rises with an increase in generalized shear strain amplitude (γga). A power function model was established to represent the relationship between εvp and γga. The coefficient ζ1 decreases as Dr increases. Comparisons were drawn between εvp and γga for Ottawa sand and SCS. The results indicate that, as Dr of Ottawa sand increases from 30 % to 70 %, the coefficient ζ1 decreases from 1.54 to 0.73, representing a reduction of approximately 53 %. In contrast, under identical conditions, the coefficient ζ1 of SCS exhibits a less pronounced decrease, from 1.16 to 0.79, corresponding to a reduction of roughly 32 %. These observations suggest that variations in Dr have a more substantial impact on generating εvp in Ottawa sand compared to SCS.
{"title":"Volumetric strain accumulation for saturated coral sand under various cyclic loading patterns","authors":"You Qin , Hui Long , Qi Wu , Wei-Jia Ma , Guo-Xing Chen , Hai-Yang Zhuang","doi":"10.1016/j.soildyn.2024.109198","DOIUrl":"10.1016/j.soildyn.2024.109198","url":null,"abstract":"<div><div>Seismic events and wave action can induce volumetric strain (<em>ε</em><sub>v</sub>) accumulation in saturated sandy soils, leading to damage to the ground surface and structures. A quantifiable relationship exists between the generation of <em>ε</em><sub>v</sub> in sandy soils under drained conditions and the development of pore water pressures under undrained conditions. In this study, the impact of relative density (<em>D</em><sub>r</sub>), cyclic stress path, and stress level on the characteristics of volumetric strain (<em>ε</em><sub>v</sub>) generation in saturated coral sands (SCS) was evaluated through drained tests employing various cyclic stress paths. The test findings demonstrate that the rate of <em>ε</em><sub>v</sub> accumulation in SCS is notably affected by the cyclic stress path. The rise in peak volumetric strain (<em>ε</em><sub>vp</sub>) in SCS, as a function of the number of cycles, conforms to the arctangent function model. The unit cyclic stress ratio (USR) was employed as an indicator of complex cyclic loading levels. It was determined that coefficient (<em>ε</em><sub>vp</sub>)<sub>u</sub> is positively correlated with USR at a specific <em>D</em><sub>r</sub>. At the same <em>D</em><sub>r</sub>, coefficient <em>C</em><sub><em>N</em>1</sub> exhibits a positive correlation with USR, while coefficient <em>C</em><sub><em>N</em>2</sub> displays a negative correlation with USR, following a power-law relationship. Irrespective of cyclic loading conditions, <em>ε</em><sub>vp</sub> rises with an increase in generalized shear strain amplitude (<em>γ</em><sub>ga</sub>). A power function model was established to represent the relationship between <em>ε</em><sub>vp</sub> and <em>γ</em><sub>ga</sub>. The coefficient <em>ζ</em><sub>1</sub> decreases as <em>D</em><sub>r</sub> increases. Comparisons were drawn between <em>ε</em><sub>vp</sub> and <em>γ</em><sub>ga</sub> for Ottawa sand and SCS. The results indicate that, as <em>D</em><sub>r</sub> of Ottawa sand increases from 30 % to 70 %, the coefficient <em>ζ</em><sub>1</sub> decreases from 1.54 to 0.73, representing a reduction of approximately 53 %. In contrast, under identical conditions, the coefficient <em>ζ</em><sub>1</sub> of SCS exhibits a less pronounced decrease, from 1.16 to 0.79, corresponding to a reduction of roughly 32 %. These observations suggest that variations in <em>D</em><sub>r</sub> have a more substantial impact on generating <em>ε</em><sub>vp</sub> in Ottawa sand compared to SCS.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109198"},"PeriodicalIF":4.2,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102493","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}
Loess slopes are prone to seismic subsidence deformation and sliding failure under seismic loads. In this paper, the dynamic centrifugal model test of the undisturbed loess slope with a geometric scale of 1: 20 is designed and completed for the typical Malan loess slope. By combining numerical simulation methods, the dynamic response and seismic subsidence failure characteristics of loess slopes under different influencing factors (excitation, moisture content, slope ratio) were analyzed. The results show that the dynamic amplification coefficient of the loess slope increases nonlinearly with the slope height, and the test results are consistent with the numerical simulation results. The crest of the loess slope undergoes significant seismic subsidence deformation, and the slope exhibits a sliding trend of lateral extrusion. Under the action of strong earthquake, the structural cracks of the undisturbed loess slope developed significantly, resulting in serious cracking damage. The seismic subsidence deformation and fracture development of loess slope are more obvious with the increase of initial moisture content. It can be seen that under the action of earthquakes, loess slopes undergo seismic subsidence, tension cracks, and structural cracks develop, forming seepage channel cracks and potential slip surfaces, providing conditions for slope sliding.
{"title":"Dynamic response of undisturbed loess slope based on dynamic centrifugal testing","authors":"Shuai Shao , Xiaocong Zhang , Zhiping Yu , Hao Wu , Shengjun Shao , Guangyi Yan","doi":"10.1016/j.soildyn.2024.109193","DOIUrl":"10.1016/j.soildyn.2024.109193","url":null,"abstract":"<div><div>Loess slopes are prone to seismic subsidence deformation and sliding failure under seismic loads. In this paper, the dynamic centrifugal model test of the undisturbed loess slope with a geometric scale of 1: 20 is designed and completed for the typical Malan loess slope. By combining numerical simulation methods, the dynamic response and seismic subsidence failure characteristics of loess slopes under different influencing factors (excitation, moisture content, slope ratio) were analyzed. The results show that the dynamic amplification coefficient of the loess slope increases nonlinearly with the slope height, and the test results are consistent with the numerical simulation results. The crest of the loess slope undergoes significant seismic subsidence deformation, and the slope exhibits a sliding trend of lateral extrusion. Under the action of strong earthquake, the structural cracks of the undisturbed loess slope developed significantly, resulting in serious cracking damage. The seismic subsidence deformation and fracture development of loess slope are more obvious with the increase of initial moisture content. It can be seen that under the action of earthquakes, loess slopes undergo seismic subsidence, tension cracks, and structural cracks develop, forming seepage channel cracks and potential slip surfaces, providing conditions for slope sliding.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109193"},"PeriodicalIF":4.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102026","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 : 2024-12-31DOI: 10.1016/j.soildyn.2024.109202
Yu Ni, Liangliang Wu, Zhibao Cheng, Zhifei Shi
Vibration mitigation is a knotty problem in the transit-oriented development (TOD) pattern. In TOD pattern, buildings such as hotels are usually very close to large transportation facilities such as railway stations. TOD pattern brings convenience to the residents, however, may affect their indoor life quality at the same time. This article provides a new design methodology for vibration mitigation of TOD pattern based on periodic theory. The original design of waterproof curtain and retaining piles used in the buildings are reformed to be a periodic wave barrier (PWB) by minor adjustment without losing their original functions. After comprehensive numerical studies on the performance of the PWB, a detailed construction of the waterproof curtain and retaining piles is suggested, and it has been applied in practical engineering. The scheme proposed in this article not only is valid in practical engineering where operable space is very small, but also comprehensively considers the items such as construction technology and economic costs. Therefore, this study provides an innovative design for waterproof curtain and retaining piles that can be cost-effective and efficient, and is with the ability of vibration mitigation at the same time.
{"title":"Vibration mitigation of a transit-oriented development building based on periodic theory","authors":"Yu Ni, Liangliang Wu, Zhibao Cheng, Zhifei Shi","doi":"10.1016/j.soildyn.2024.109202","DOIUrl":"10.1016/j.soildyn.2024.109202","url":null,"abstract":"<div><div>Vibration mitigation is a knotty problem in the transit-oriented development (TOD) pattern. In TOD pattern, buildings such as hotels are usually very close to large transportation facilities such as railway stations. TOD pattern brings convenience to the residents, however, may affect their indoor life quality at the same time. This article provides a new design methodology for vibration mitigation of TOD pattern based on periodic theory. The original design of waterproof curtain and retaining piles used in the buildings are reformed to be a periodic wave barrier (PWB) by minor adjustment without losing their original functions. After comprehensive numerical studies on the performance of the PWB, a detailed construction of the waterproof curtain and retaining piles is suggested, and it has been applied in practical engineering. The scheme proposed in this article not only is valid in practical engineering where operable space is very small, but also comprehensively considers the items such as construction technology and economic costs. Therefore, this study provides an innovative design for waterproof curtain and retaining piles that can be cost-effective and efficient, and is with the ability of vibration mitigation at the same time.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109202"},"PeriodicalIF":4.2,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102027","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 : 2024-12-31DOI: 10.1016/j.soildyn.2024.109199
Banfu Yan , Junjiang Lai , Suiwen Wu , Shipeng Feng , Xiangcheng Meng
It is known that different types of bridge structures exhibit significant variations in the selection of ground motion IMs due to differences in their dynamic characteristics. Additionally, the dynamic characteristics of UHPC ribbed arch bridges differ from those of conventional bridge structures. Conclusions about the seismic fragility of conventional bridge structures derived from previous studies may not be applicable to this specific bridge. In this paper, seismic fragility of UHPC ribbed arch bridges is assessed through the Incremental Dynamic Analysis Method (IDA). For this purpose, an 85m UHPC ribbed arch bridge is selected as the engineering background. The 3-D finite element model of the bridge was established using OpenSees. Subsequently, 12 far-field and 12 near-field ground motion records were selected for nonlinear time-history analysis of the structure. Damage indexes for the arch ribs and tie beams were defined according to the seismic response characteristics of bridge, with the sectional curvature of five locations within these components serving as engineering demand parameters (EDPs). These EDPs were subjected to logarithmic regression analysis with respect to 8 ground motion intensity measures (IMs), aiming to evaluate the efficiency, practicability and proficiency of each IM, and to identify the optimal ground motion IM for this type of bridge. Finally, fragility curves for the arch ribs and tie beams were developed based on the fragility method, pinpointing the seismic vulnerable components of the bridge and assessing the overall seismic performance of the structure. The results indicate that the spectral acceleration at the fundamental period of the structure SAT1 is the optimal IM for fragility analysis of this bridge, followed by the effective peak acceleration EPA and acceleration-based IMs. In addition, under transverse ground motion excitations, the most vulnerable component of the bridge is found to be the E-type tie beam, followed by the springing position of the exterior arch rib. Within the given range of ground motion intensity, the bridge damage will be concentrated on non-structural components (tie beams and bridge deck). The results can provide the guidance for the seismic vulnerability assessment of UHPC ribbed arch bridges.
{"title":"Seismic fragility assessment of UHPC ribbed arch bridges","authors":"Banfu Yan , Junjiang Lai , Suiwen Wu , Shipeng Feng , Xiangcheng Meng","doi":"10.1016/j.soildyn.2024.109199","DOIUrl":"10.1016/j.soildyn.2024.109199","url":null,"abstract":"<div><div>It is known that different types of bridge structures exhibit significant variations in the selection of ground motion IMs due to differences in their dynamic characteristics. Additionally, the dynamic characteristics of UHPC ribbed arch bridges differ from those of conventional bridge structures. Conclusions about the seismic fragility of conventional bridge structures derived from previous studies may not be applicable to this specific bridge. In this paper, seismic fragility of UHPC ribbed arch bridges is assessed through the Incremental Dynamic Analysis Method (IDA). For this purpose, an 85m UHPC ribbed arch bridge is selected as the engineering background. The 3-D finite element model of the bridge was established using OpenSees. Subsequently, 12 far-field and 12 near-field ground motion records were selected for nonlinear time-history analysis of the structure. Damage indexes for the arch ribs and tie beams were defined according to the seismic response characteristics of bridge, with the sectional curvature of five locations within these components serving as engineering demand parameters (EDPs). These EDPs were subjected to logarithmic regression analysis with respect to 8 ground motion intensity measures (IMs), aiming to evaluate the efficiency, practicability and proficiency of each IM, and to identify the optimal ground motion IM for this type of bridge. Finally, fragility curves for the arch ribs and tie beams were developed based on the fragility method, pinpointing the seismic vulnerable components of the bridge and assessing the overall seismic performance of the structure. The results indicate that the spectral acceleration at the fundamental period of the structure SAT1 is the optimal IM for fragility analysis of this bridge, followed by the effective peak acceleration EPA and acceleration-based IMs. In addition, under transverse ground motion excitations, the most vulnerable component of the bridge is found to be the E-type tie beam, followed by the springing position of the exterior arch rib. Within the given range of ground motion intensity, the bridge damage will be concentrated on non-structural components (tie beams and bridge deck). The results can provide the guidance for the seismic vulnerability assessment of UHPC ribbed arch bridges.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109199"},"PeriodicalIF":4.2,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102028","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 : 2024-12-31DOI: 10.1016/j.soildyn.2024.109189
Chao Liang , Jianyun Chen , Jing Li , Qiang Xu , Cao Xiangyu , Pengfei Liu
The influence of ground motion selection and dynamic analysis methods on the seismic fragility and risk analysis of high arch dams has not been sufficiently investigated in existing studies. The widely adopted Incremental Dynamic Analysis (IDA) method often fails to adequately capture the variations in ground motion characteristics across different seismic intensity levels, which can result in significant discrepancies in the arch dam's responses. Additionally, due to complex damage patterns under strong seismic events and insufficient empirical data, inconsistencies persist in evaluating seismic damage indices for high arch dams. To address these issues, an improved IDA method that considers hazard consistency is proposed. The robust Multiple Stripe Analysis (MSA) was used as a benchmark to refine the IDA method, incorporating hazard consistency and improving analytical efficiency. The correlation between residual displacement gradient (RDG) indices and the overall and localized damage indices was further analyzed, enabling unified quantification of damage thresholds for the Baihetan arch dam at various limit states. The improved IDA method proved effective in assessing seismic risk within a defined scaling range, but it was observed to overestimate seismic demands at low exceedance probability levels and in severe damage states. Establishing unified performance levels and objectives for high arch dams is recommended to provide a more reliable foundation for identifying damage states and making informed reinforcement decisions under strong earthquakes.
{"title":"Research on an improved dynamic analysis method for performance-based probabilistic hazard analysis of structural demand parameters in high arch dams","authors":"Chao Liang , Jianyun Chen , Jing Li , Qiang Xu , Cao Xiangyu , Pengfei Liu","doi":"10.1016/j.soildyn.2024.109189","DOIUrl":"10.1016/j.soildyn.2024.109189","url":null,"abstract":"<div><div>The influence of ground motion selection and dynamic analysis methods on the seismic fragility and risk analysis of high arch dams has not been sufficiently investigated in existing studies. The widely adopted Incremental Dynamic Analysis (IDA) method often fails to adequately capture the variations in ground motion characteristics across different seismic intensity levels, which can result in significant discrepancies in the arch dam's responses. Additionally, due to complex damage patterns under strong seismic events and insufficient empirical data, inconsistencies persist in evaluating seismic damage indices for high arch dams. To address these issues, an improved IDA method that considers hazard consistency is proposed. The robust Multiple Stripe Analysis (MSA) was used as a benchmark to refine the IDA method, incorporating hazard consistency and improving analytical efficiency. The correlation between residual displacement gradient (<em>RDG</em>) indices and the overall and localized damage indices was further analyzed, enabling unified quantification of damage thresholds for the Baihetan arch dam at various limit states. The improved IDA method proved effective in assessing seismic risk within a defined scaling range, but it was observed to overestimate seismic demands at low exceedance probability levels and in severe damage states. Establishing unified performance levels and objectives for high arch dams is recommended to provide a more reliable foundation for identifying damage states and making informed reinforcement decisions under strong earthquakes.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109189"},"PeriodicalIF":4.2,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143101529","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 : 2024-12-30DOI: 10.1016/j.soildyn.2024.109201
Du Jifang , Wu Shuaifeng , Hou Sen , Zhang Yinqiu , Cai Hong , Wei Yingqi , Shi Junwei
Dynamic compaction (DC) is widely used to improve ground with various soil types and environmental conditions. In this study, large-scale field tests at Daxing Airport were proposed to investigate the dynamic characteristics of soil induced by DC under three energy levels (1000 kN m, 1500 kN m, and 2000 kN m). Standard penetration test (SPT), pressuremeter test (PMT), and vibration (velocity and acceleration) tests were conducted to measure the variation in soil properties. The results show that, in the tamping process, the vibration amplitudes were stabilized after a certain number of blows, which has a similar variation trend as the crater settlements. A critical vibration acceleration of 5g was obtained through the correlation between the vibration and soil properties, indicating that when the vibration acceleration exceeded 5g, the soil properties changed significantly. These findings provide a reference for the development of real-time diagnosis of compaction state based on the vibration tests.
{"title":"Dynamic response and densification mechanism of dynamic compaction for silt soil through a large scale field test at Daxing Airport","authors":"Du Jifang , Wu Shuaifeng , Hou Sen , Zhang Yinqiu , Cai Hong , Wei Yingqi , Shi Junwei","doi":"10.1016/j.soildyn.2024.109201","DOIUrl":"10.1016/j.soildyn.2024.109201","url":null,"abstract":"<div><div>Dynamic compaction (DC) is widely used to improve ground with various soil types and environmental conditions. In this study, large-scale field tests at Daxing Airport were proposed to investigate the dynamic characteristics of soil induced by DC under three energy levels (1000 kN m, 1500 kN m, and 2000 kN m). Standard penetration test (SPT), pressuremeter test (PMT), and vibration (velocity and acceleration) tests were conducted to measure the variation in soil properties. The results show that, in the tamping process, the vibration amplitudes were stabilized after a certain number of blows, which has a similar variation trend as the crater settlements. A critical vibration acceleration of 5g was obtained through the correlation between the vibration and soil properties, indicating that when the vibration acceleration exceeded 5g, the soil properties changed significantly. These findings provide a reference for the development of real-time diagnosis of compaction state based on the vibration tests.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"190 ","pages":"Article 109201"},"PeriodicalIF":4.2,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143101528","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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