Soil Dynamics and Earthquake Engineering最新文献_第5页

AI-assisted analytical model of seismic displacement estimation for frictional isolated bridge portfolios under pulse-like ground motions 人工智能辅助分析模型：脉冲地动下摩擦孤立桥梁组合的地震位移估算

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-09-25 DOI: 10.1016/j.soildyn.2024.108991

Accurate bearing displacement assessment is crucial for frictional isolated bridges under pulse-like ground motions. In order to cope with the efficiency requirement brought by large-scale bridge portfolio estimation, the artificial intelligence (AI) method, a powerful tool to address multi-parameter issues, is widely adopted in seismic performance analysis for bridge networks. However, the traditional machine learning (TML) method pursues the overall prediction performance, the prediction effect in sensitive intervals caused by pulse-effect can not be assured. To face this challenge, this study proposed an AI-assisted analytical (AIA) method, which owns the characteristics of high efficiency, high accuracy and clear physical meaning. In the first step of the AIA method, the relationship between primary factor (pulse period) and output (seismic displacement) is established through an analytical model; in the second step, the undetermined parameters of the analytical model are estimated with the assistance of the AI method. The results indicate that the AIA model only requires 0.1 times data for model training and achieves overall predictive performance similar to TML methods. Moreover, the predictive effect of the AIA model in the sensitive range is greatly improved compared to the TML method. Finally, based on AIA method, an effective seismic fragility prediction method is proposed for frictional isolated bridge networks. The fragility curves illustrated by AIA method and FE analysis are in good agreement, which exhibited the satisfactory efficiency of the proposed AIA method.

精确的支座位移评估对于脉冲地动下的摩擦隔震桥梁至关重要。为了应对大规模桥梁组合估算带来的效率要求，人工智能（AI）方法作为解决多参数问题的有力工具，在桥梁网络抗震性能分析中被广泛采用。然而，传统的机器学习（TML）方法追求的是整体预测性能，对脉冲效应引起的敏感区间的预测效果无法保证。面对这一难题，本研究提出了一种人工智能辅助分析（AIA）方法，该方法具有效率高、精度高、物理意义明确等特点。AIA 方法的第一步是通过分析模型建立主因子（脉冲周期）与输出（地震位移）之间的关系；第二步是利用人工智能方法对分析模型中的未确定参数进行估计。结果表明，AIA 模型只需要 0.1 倍的数据进行模型训练，就能达到与 TML 方法相似的整体预测性能。此外，与 TML 方法相比，AIA 模型在敏感范围内的预测效果有很大提高。最后，基于 AIA 方法，提出了一种有效的摩擦孤立桥网地震脆性预测方法。AIA 方法和 FE 分析得出的脆性曲线具有良好的一致性，这表明所提出的 AIA 方法具有令人满意的效率。

{"title":"AI-assisted analytical model of seismic displacement estimation for frictional isolated bridge portfolios under pulse-like ground motions","authors":"","doi":"10.1016/j.soildyn.2024.108991","DOIUrl":"10.1016/j.soildyn.2024.108991","url":null,"abstract":"<div><div>Accurate bearing displacement assessment is crucial for frictional isolated bridges under pulse-like ground motions. In order to cope with the efficiency requirement brought by large-scale bridge portfolio estimation, the artificial intelligence (AI) method, a powerful tool to address multi-parameter issues, is widely adopted in seismic performance analysis for bridge networks. However, the traditional machine learning (TML) method pursues the overall prediction performance, the prediction effect in sensitive intervals caused by pulse-effect can not be assured. To face this challenge, this study proposed an AI-assisted analytical (AIA) method, which owns the characteristics of high efficiency, high accuracy and clear physical meaning. In the first step of the AIA method, the relationship between primary factor (pulse period) and output (seismic displacement) is established through an analytical model; in the second step, the undetermined parameters of the analytical model are estimated with the assistance of the AI method. The results indicate that the AIA model only requires 0.1 times data for model training and achieves overall predictive performance similar to TML methods. Moreover, the predictive effect of the AIA model in the sensitive range is greatly improved compared to the TML method. Finally, based on AIA method, an effective seismic fragility prediction method is proposed for frictional isolated bridge networks. The fragility curves illustrated by AIA method and FE analysis are in good agreement, which exhibited the satisfactory efficiency of the proposed AIA method.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319180","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}

引用次数: 0

Nonlinear numerical study of structure-soil-structure interaction effects between conventional and three-dimensional base-isolated nuclear power plants 常规和三维基座隔离核电站结构-土壤-结构相互作用效应的非线性数值研究

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-09-25 DOI: 10.1016/j.soildyn.2024.108985

The three-dimensional (3D) isolation technology holds immense potential in the field of nuclear power plants (NPPs) due to its proficiency in mitigating vertical seismic impacts. In practice projects, multi-unit NPPs are a common form. As the site conditions become increasingly complex, the structure-soil-structure interaction (SSSI) effects are crucial in seismic assessments of NPPs. This study endeavours to meticulously simulate the scenarios where adjacent nuclear units are subjected to super-strong earthquakes. A novel time-domain coupled model and its computational procedure for nonlinear SSSI seismic analysis are proposed, and system models of ten NPPs are established to analyze the seismic responses of NPPs in firm rock and hard soil sites, and the impact of SSSI on the dynamic responses of conventional and 3D base-isolated NPPs is investigated in detail. Key findings illustrate that the SSSI effects on both conventional and 3D base-isolated NPPs are dependent on specific site conditions and inherent structural properties. For both conventional and 3D base-isolated NPPs, the floor response spectra and acceleration responses of a single NPP cannot fully envelope the scenarios where SSSI effects are considered. Furthermore, SSSI effects exert a more substantial influence on conventional NPPs compared to 3D base-isolated NPPs, with heightened effects at sites characterised by lower shear-wave velocities. These results furnish theoretical underpinnings for the seismic evaluation of multi-unit NPPs and the practical implementation of 3D base isolation in NPPs.

三维（3D）隔震技术在核电站（NPP）领域具有巨大的潜力，因为它能有效减轻垂直地震影响。在实际项目中，多机组核电站是一种常见形式。由于现场条件日益复杂，结构-土壤-结构相互作用（SSSI）效应在核电站地震评估中至关重要。本研究致力于细致模拟相邻核电机组遭受超强地震的情况。研究提出了一种新型时域耦合模型及其计算程序，用于非线性 SSSI 地震分析，并建立了十座核电站的系统模型，分析了坚硬岩石和硬土场地中核电站的地震响应，详细研究了 SSSI 对常规和三维基底隔离核电站动态响应的影响。主要研究结果表明，SSSI 对常规和三维基底隔离核电站的影响取决于具体的场地条件和固有的结构特性。对于传统和三维基座隔离型核电厂，单个核电厂的地板响应谱和加速度响应不能完全涵盖考虑 SSSI 效应的情况。此外，与三维基底隔离式核电站相比，SSSI 效应对传统核电站的影响更大，在剪切波速度较低的地点，SSSI 效应的影响更大。这些结果为多单元核电厂的地震评估和在核电厂中实际实施三维基底隔离提供了理论依据。

{"title":"Nonlinear numerical study of structure-soil-structure interaction effects between conventional and three-dimensional base-isolated nuclear power plants","authors":"","doi":"10.1016/j.soildyn.2024.108985","DOIUrl":"10.1016/j.soildyn.2024.108985","url":null,"abstract":"<div><div>The three-dimensional (3D) isolation technology holds immense potential in the field of nuclear power plants (NPPs) due to its proficiency in mitigating vertical seismic impacts. In practice projects, multi-unit NPPs are a common form. As the site conditions become increasingly complex, the structure-soil-structure interaction (SSSI) effects are crucial in seismic assessments of NPPs. This study endeavours to meticulously simulate the scenarios where adjacent nuclear units are subjected to super-strong earthquakes. A novel time-domain coupled model and its computational procedure for nonlinear SSSI seismic analysis are proposed, and system models of ten NPPs are established to analyze the seismic responses of NPPs in firm rock and hard soil sites, and the impact of SSSI on the dynamic responses of conventional and 3D base-isolated NPPs is investigated in detail. Key findings illustrate that the SSSI effects on both conventional and 3D base-isolated NPPs are dependent on specific site conditions and inherent structural properties. For both conventional and 3D base-isolated NPPs, the floor response spectra and acceleration responses of a single NPP cannot fully envelope the scenarios where SSSI effects are considered. Furthermore, SSSI effects exert a more substantial influence on conventional NPPs compared to 3D base-isolated NPPs, with heightened effects at sites characterised by lower shear-wave velocities. These results furnish theoretical underpinnings for the seismic evaluation of multi-unit NPPs and the practical implementation of 3D base isolation in NPPs.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319181","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}

引用次数: 0

Seismic response control of tall building using semi-active tuned mass damper considering soil-structure interaction 考虑到土-结构相互作用，使用半主动调谐质量阻尼器控制高层建筑的地震响应

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-09-24 DOI: 10.1016/j.soildyn.2024.108987

Soil-structure interaction (SSI) will change structural characteristics of a tall building, while parameters of the passive tuned mass damper (TMD) should be specifically optimized in this case. However, the structural model and soil parameters are full of uncertainties, and the seismic response mitigation of passive TMD suffers from the frequency and damping detuning. To improve its seismic performance, the semi-active TMD (STMD) is presented in this study, which can adjust frequency and damping ratio simultaneously. It can not only add or remove its mass to retune the frequency, but the eddy current damping ratio can also be adjusted in real time by reset the air gap, according to a developed output signals based solely combined algorithm. To verify its seismic mitigation performance preliminarily, a SDOF main structure is investigated, while it is found that when the frequency detuning occurs on the STMD with variable damping solely, a significant performance degradation is detected; while STMD with variable frequency and damping ratio always has the best control performance. Then, a 40-story benchmark high-rise building with different SSI types is presented as the case study. Numerical results show that STMD can reduce structural displacement responses effectively and has a better control performance than optimal passive TMD for each model. Meanwhile, frequency detuning of passive TMD is discussed and degradation of robustness is found in the passive TMD with ±15 % stiffness detuning. It can be known that proposed STMD has the best control robustness as well, because it is always tuned.

土-结构相互作用（SSI）会改变高层建筑的结构特征，而被动式调谐质量阻尼器（TMD）的参数在这种情况下需要特别优化。然而，结构模型和土壤参数充满了不确定性，被动式 TMD 的地震响应减缓受到频率和阻尼失谐的影响。为改善其抗震性能，本研究提出了可同时调节频率和阻尼比的半主动 TMD（STMD）。它不仅可以增减质量来调整频率，还可以根据开发的基于输出信号的唯一组合算法，通过重置气隙来实时调整涡流阻尼比。为了初步验证其抗震减灾性能，我们对一个 SDOF 主体结构进行了研究，结果发现，当频率失谐发生在单阻尼可变的 STMD 上时，会出现明显的性能下降；而频率和阻尼比可变的 STMD 始终具有最佳的控制性能。随后，以一栋 40 层的基准高层建筑为例，介绍了不同 SSI 类型。数值结果表明，对于每个模型，STMD 都能有效降低结构位移响应，其控制性能优于最佳被动 TMD。同时，还讨论了被动式 TMD 的频率失谐问题，发现刚度失谐为 ±15 % 的被动式 TMD 的稳健性有所下降。可以看出，由于 STMD 始终处于调谐状态，因此所提出的 STMD 也具有最佳的控制鲁棒性。

{"title":"Seismic response control of tall building using semi-active tuned mass damper considering soil-structure interaction","authors":"","doi":"10.1016/j.soildyn.2024.108987","DOIUrl":"10.1016/j.soildyn.2024.108987","url":null,"abstract":"<div><div>Soil-structure interaction (SSI) will change structural characteristics of a tall building, while parameters of the passive tuned mass damper (TMD) should be specifically optimized in this case. However, the structural model and soil parameters are full of uncertainties, and the seismic response mitigation of passive TMD suffers from the frequency and damping detuning. To improve its seismic performance, the semi-active TMD (STMD) is presented in this study, which can adjust frequency and damping ratio simultaneously. It can not only add or remove its mass to retune the frequency, but the eddy current damping ratio can also be adjusted in real time by reset the air gap, according to a developed output signals based solely combined algorithm. To verify its seismic mitigation performance preliminarily, a SDOF main structure is investigated, while it is found that when the frequency detuning occurs on the STMD with variable damping solely, a significant performance degradation is detected; while STMD with variable frequency and damping ratio always has the best control performance. Then, a 40-story benchmark high-rise building with different SSI types is presented as the case study. Numerical results show that STMD can reduce structural displacement responses effectively and has a better control performance than optimal passive TMD for each model. Meanwhile, frequency detuning of passive TMD is discussed and degradation of robustness is found in the passive TMD with ±15 % stiffness detuning. It can be known that proposed STMD has the best control robustness as well, because it is always tuned.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311728","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}

引用次数: 0

Seismic design of a low-carbon building constructed with in-situ produced compressed earth blocks 用就地生产的压缩土块建造低碳建筑的抗震设计

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-09-24 DOI: 10.1016/j.soildyn.2024.108990

The seismic design of buildings erected using new low-carbon construction materials needs the development of a reliable methodology. In this research, a pilot project of a compressed earth block (CEB) masonry building in a medium-high seismic hazard zone in Southern France is developed. The CEBs are produced in-situ, using a machine, and are used as construction material for low-rise masonry buildings. This innovative low-carbon construction technology permits the reuse of local soil, removed during earthworks, with consequent reduction of energy consumption related to its collection, transport, recovery, and disposal. Even if the CEB masonry building is a promising low-carbon construction, its structural performance assessment, especially in seismic zones, is a challenging issue.

Starting from the experimental characterization of material mechanical parameters, the seismic design approach focuses on the modal characteristics of the structure, the expected building ductility, and seismic performance assessment in terms of both displacement and force. The behavior factor for a CEB masonry building is an original result of this research. The equivalent frame model adopted for structural design of load-bearing masonry is validated, after the building construction, by comparing the dynamic properties obtained by both numerical and operational modal analysis. Moreover, the modal analysis highlights the impact of the timber slab stiffness on the dynamic response of masonry buildings and suggests that a careful timber slab conception improves the structural behavior under seismic loading.

对使用新型低碳建筑材料建造的建筑物进行抗震设计需要开发一种可靠的方法。在这项研究中，开发了一个在法国南部中高地震危险区建造压缩土块（CEB）砌体建筑的试点项目。压缩土砌块使用机器就地生产，用作低层砌体建筑的建筑材料。这种创新的低碳建筑技术可以重新利用土方工程中移除的当地土壤，从而减少与土壤收集、运输、回收和处理相关的能源消耗。尽管 CEB 砌体建筑是一种前景广阔的低碳建筑，但其结构性能评估，尤其是在地震带上的结构性能评估，却是一个具有挑战性的问题。从材料力学参数的实验表征开始，抗震设计方法侧重于结构的模态特征、预期的建筑延性以及位移和力方面的抗震性能评估。CEB 砌体建筑的行为系数是这项研究的原创性成果。建筑物建成后，通过比较数值分析和运行模态分析获得的动态特性，验证了用于承重砌体结构设计的等效框架模型。此外，模态分析凸显了木板刚度对砌体建筑动态响应的影响，并表明精心的木板构思可改善地震荷载下的结构行为。

{"title":"Seismic design of a low-carbon building constructed with in-situ produced compressed earth blocks","authors":"","doi":"10.1016/j.soildyn.2024.108990","DOIUrl":"10.1016/j.soildyn.2024.108990","url":null,"abstract":"<div><div>The seismic design of buildings erected using new low-carbon construction materials needs the development of a reliable methodology. In this research, a pilot project of a compressed earth block (CEB) masonry building in a medium-high seismic hazard zone in Southern France is developed. The CEBs are produced in-situ, using a machine, and are used as construction material for low-rise masonry buildings. This innovative low-carbon construction technology permits the reuse of local soil, removed during earthworks, with consequent reduction of energy consumption related to its collection, transport, recovery, and disposal. Even if the CEB masonry building is a promising low-carbon construction, its structural performance assessment, especially in seismic zones, is a challenging issue.</div><div>Starting from the experimental characterization of material mechanical parameters, the seismic design approach focuses on the modal characteristics of the structure, the expected building ductility, and seismic performance assessment in terms of both displacement and force. The behavior factor for a CEB masonry building is an original result of this research. The equivalent frame model adopted for structural design of load-bearing masonry is validated, after the building construction, by comparing the dynamic properties obtained by both numerical and operational modal analysis. Moreover, the modal analysis highlights the impact of the timber slab stiffness on the dynamic response of masonry buildings and suggests that a careful timber slab conception improves the structural behavior under seismic loading.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314573","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}

引用次数: 0

Seismic behavior evaluation of friction-bearing type connection with slit dampers 带狭缝阻尼器的摩擦承载式连接的抗震性能评估

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-09-23 DOI: 10.1016/j.soildyn.2024.108988

Ductility-based design for structural collapse prevention may not be sufficient for the higher performance demand of minimizing the time and cost for function recovery. A friction-bearing type connection with slit dampers was introduced to the beam system at the beam end, and it followed the characteristics of the damage-controlled type connection. The design considerations for the proposed connection were presented and the experimental investigation on the cyclic behavior of the designed specimens was conducted. The results demonstrated that the designed connection exhibited a stable and full hysteresis behavior under cyclic loading, without obvious performance degradation. With a longer slotted hole in the slit damper, the friction-slipping behavior was obvious and the maximum rotation angle could be up to 0.05 rad, while the bearing capacity was enhanced with a shorter slotted hole. The friction-slipping behavior also improved the stress development of main structural members and enhanced the ductile behavior. The proposed connection could develop two-stage energy dissipation behavior, and the frictional slippage was greatly helpful for dissipating energy. The damage concentration was achieved, and the energy dissipated by the proposed connection accounted for more than 75 % of the total dissipated energy. The the inelastic deformation was mainly concentrated in the slit damper, while the beam and the column remained elastic, greatly improving the seismic resilience.

基于延性的结构坍塌预防设计可能无法满足功能恢复时间和成本最小化的更高性能要求。我们在梁端引入了带有狭缝阻尼器的摩擦承载式连接，它遵循了损伤控制式连接的特点。介绍了拟议连接的设计考虑因素，并对设计试样的循环行为进行了实验研究。结果表明，所设计的连接在循环载荷下表现出稳定的全滞后行为，没有明显的性能下降。当狭缝阻尼器中的槽孔较长时，摩擦滑移行为明显，最大旋转角度可达 0.05 rad，而槽孔较短时，承载能力增强。摩擦滑移行为还改善了主要结构件的应力发展，增强了延展性。所提出的连接可产生两级消能行为，摩擦滑移对消能大有帮助。该连接实现了损伤集中，其耗散的能量占总耗散能量的 75% 以上。非弹性变形主要集中在狭缝阻尼器上，而梁和柱则保持弹性，大大提高了抗震能力。

{"title":"Seismic behavior evaluation of friction-bearing type connection with slit dampers","authors":"","doi":"10.1016/j.soildyn.2024.108988","DOIUrl":"10.1016/j.soildyn.2024.108988","url":null,"abstract":"<div><div>Ductility-based design for structural collapse prevention may not be sufficient for the higher performance demand of minimizing the time and cost for function recovery. A friction-bearing type connection with slit dampers was introduced to the beam system at the beam end, and it followed the characteristics of the damage-controlled type connection. The design considerations for the proposed connection were presented and the experimental investigation on the cyclic behavior of the designed specimens was conducted. The results demonstrated that the designed connection exhibited a stable and full hysteresis behavior under cyclic loading, without obvious performance degradation. With a longer slotted hole in the slit damper, the friction-slipping behavior was obvious and the maximum rotation angle could be up to 0.05 rad, while the bearing capacity was enhanced with a shorter slotted hole. The friction-slipping behavior also improved the stress development of main structural members and enhanced the ductile behavior. The proposed connection could develop two-stage energy dissipation behavior, and the frictional slippage was greatly helpful for dissipating energy. The damage concentration was achieved, and the energy dissipated by the proposed connection accounted for more than 75 % of the total dissipated energy. The the inelastic deformation was mainly concentrated in the slit damper, while the beam and the column remained elastic, greatly improving the seismic resilience.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311727","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}

引用次数: 0

Seismic analysis of asphalt concrete core rockfill dams considering the bimodulus effect 考虑双模量效应的沥青混凝土核心堆石坝抗震分析

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-09-23 DOI: 10.1016/j.soildyn.2024.108984

In China, with the extensive development of pumped storage power stations, asphalt concrete core rockfill dams have become the preferred dam type because of their good deformation adaptability and impermeability. In seismic-prone western regions of China, the seismic safety of asphalt concrete cores is particularly important. However, asphalt concrete materials used in hydraulic engineering exhibit significant differences in their tensile and compressive moduli under low-temperature conditions, which has not been considered in existing constitutive models. In this study, a dynamic constitutive model considering the bimodulus effect of asphalt concrete was developed on the basis of dynamic tension and compression tests. Using this model, the influence of the bimodulus characteristics on the dynamic response of the core was investigated. The results indicate that a bimodulus constitutive model can effectively simulate the stress‒strain relationship of asphalt concrete materials at low temperatures. Compared with the bimodulus model, the use of the monomodulus model for calculations results in a significant decrease in compressive stress and a substantial increase in tensile stress of the core. Specifically, using the tensile and compressive monomodulus models led to maximum reductions in tensile stress of 42.9 % and an increase by 336.8 %, respectively. Neglecting the bimodulus effect may lead to misjudgment of the damage area, so the bimodulus effect on the seismic safety of dam cores should not be ignored.

在中国，随着抽水蓄能电站的广泛发展，沥青混凝土岩心堆石坝因其良好的变形适应性和抗渗性而成为首选坝型。在地震多发的中国西部地区，沥青混凝土岩心的抗震安全性尤为重要。然而，水利工程中使用的沥青混凝土材料在低温条件下的拉伸模量和压缩模量存在显著差异，而现有的构造模型并未考虑到这一点。本研究以动态拉伸和压缩试验为基础，建立了考虑沥青混凝土双模量效应的动态构造模型。利用该模型，研究了双模量特性对核心动态响应的影响。结果表明，双模量构成模型可以有效模拟沥青混凝土材料在低温下的应力-应变关系。与双模量模型相比，使用单模量模型进行计算会导致芯材的压应力显著下降，而拉应力大幅上升。具体而言，使用拉伸和压缩单模量模型可使拉伸应力最大分别减少 42.9% 和增加 336.8%。忽视双模量效应可能会导致对破坏区域的错误判断，因此不应忽视双模量效应对坝心抗震安全的影响。

{"title":"Seismic analysis of asphalt concrete core rockfill dams considering the bimodulus effect","authors":"","doi":"10.1016/j.soildyn.2024.108984","DOIUrl":"10.1016/j.soildyn.2024.108984","url":null,"abstract":"<div><div>In China, with the extensive development of pumped storage power stations, asphalt concrete core rockfill dams have become the preferred dam type because of their good deformation adaptability and impermeability. In seismic-prone western regions of China, the seismic safety of asphalt concrete cores is particularly important. However, asphalt concrete materials used in hydraulic engineering exhibit significant differences in their tensile and compressive moduli under low-temperature conditions, which has not been considered in existing constitutive models. In this study, a dynamic constitutive model considering the bimodulus effect of asphalt concrete was developed on the basis of dynamic tension and compression tests. Using this model, the influence of the bimodulus characteristics on the dynamic response of the core was investigated. The results indicate that a bimodulus constitutive model can effectively simulate the stress‒strain relationship of asphalt concrete materials at low temperatures. Compared with the bimodulus model, the use of the monomodulus model for calculations results in a significant decrease in compressive stress and a substantial increase in tensile stress of the core. Specifically, using the tensile and compressive monomodulus models led to maximum reductions in tensile stress of 42.9 % and an increase by 336.8 %, respectively. Neglecting the bimodulus effect may lead to misjudgment of the damage area, so the bimodulus effect on the seismic safety of dam cores should not be ignored.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311726","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}

引用次数: 0

Study on practical calculation method of post-earthquake traffic capacity of high-speed railway bridge 高速铁路桥梁震后通行能力实用计算方法研究

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-09-23 DOI: 10.1016/j.soildyn.2024.108983

High-speed railway bridges are critical lifeline infrastructure during earthquake rescue operations. To effectively evaluate the post-earthquake capacity of high-speed railway bridge, an intensity index system of the post-earthquake track irregularity. spectrum was proposed considering earthquake and structural randomness. A mapping relationship between post-earthquake track irregularity. spectrum intensity index and post-earthquake driving performance index on bridge was established. A practical calculation method for the post-earthquake driving speed threshold of high-speed railway bridge, demonstrating the rationality and effectiveness of this method through case analysis. The results indicated that the post-earthquake driving performance index on bridge correlates approximately linearly with the intensity index of the post-earthquake track irregularity. spectrum. The post-earthquake driving performance targets on bridge can be categorized into safety and comfort targets. The post-earthquake driving performance evaluation criteria based on the comfort target impose stricter speed controls. The practical calculation method for assessing the post-earthquake capacity of high-speed railway bridge is simple, facilitates manual calculations, and possesses significant engineering applicability, providing a solid theoretical foundation for developing post-earthquake emergency plans and the performance-based seismic design of high-speed railway bridge.

高速铁路桥梁是地震救援行动中至关重要的生命线基础设施。为有效评价高速铁路桥梁的震后承载能力，提出了考虑地震和结构随机性的震后轨道不规则谱强度指标体系，建立了震后轨道不规则谱强度指标与桥梁震后行车性能指标的映射关系。建立了震后轨道不规则谱强度指标与桥梁震后行车性能指标之间的映射关系。提出了高速铁路桥梁震后行车速度阈值的实用计算方法，并通过实例分析论证了该方法的合理性和有效性。结果表明，震后桥梁行车性能指标与震后轨道不平顺强度指数近似线性相关。震后桥梁行驶性能指标可分为安全性指标和舒适性指标。基于舒适性目标的震后行车性能评估标准规定了更严格的速度控制。高速铁路桥梁震后承载力评估的实用计算方法简单，便于人工计算，具有重要的工程适用性，为制定高速铁路桥梁震后应急预案和基于性能的抗震设计提供了坚实的理论基础。

{"title":"Study on practical calculation method of post-earthquake traffic capacity of high-speed railway bridge","authors":"","doi":"10.1016/j.soildyn.2024.108983","DOIUrl":"10.1016/j.soildyn.2024.108983","url":null,"abstract":"<div><div>High-speed railway bridges are critical lifeline infrastructure during earthquake rescue operations. To effectively evaluate the post-earthquake capacity of high-speed railway bridge, an intensity index system of the post-earthquake track irregularity. spectrum was proposed considering earthquake and structural randomness. A mapping relationship between post-earthquake track irregularity. spectrum intensity index and post-earthquake driving performance index on bridge was established. A practical calculation method for the post-earthquake driving speed threshold of high-speed railway bridge, demonstrating the rationality and effectiveness of this method through case analysis. The results indicated that the post-earthquake driving performance index on bridge correlates approximately linearly with the intensity index of the post-earthquake track irregularity. spectrum. The post-earthquake driving performance targets on bridge can be categorized into safety and comfort targets. The post-earthquake driving performance evaluation criteria based on the comfort target impose stricter speed controls. The practical calculation method for assessing the post-earthquake capacity of high-speed railway bridge is simple, facilitates manual calculations, and possesses significant engineering applicability, providing a solid theoretical foundation for developing post-earthquake emergency plans and the performance-based seismic design of high-speed railway bridge.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311725","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}

引用次数: 0

Response of flexible pipes buried in sand under multi-directional movement: understanding fault-pipeline interaction 埋在沙中的柔性管道在多向运动下的响应：了解断层与管道的相互作用

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-09-21 DOI: 10.1016/j.soildyn.2024.108978

Buried pipelines are an integral part of critical lifeline systems, and span across wide geographic areas to convey fluid products for human use. Due to geohazards, pipelines could be subjected to transverse displacements in different directions, i.e., displacements normal to the pipe axis. However, limited experimental studies have been reported on the response of flexible pipes when subjected to such displacements. In this study, fourteen large-scale multi-directional dragging tests were conducted on polyvinyl chloride (PVC) pipes in dry sand to promote a better understanding of flexible pipe-soil interaction. The soil restraint, midspan deflection, circumferential strain, and longitudinal strain are found to increase with the pipe embedment depth and decrease with the loading angle. It is observed that the design guidelines of ALA (2005) largely overestimate the peak soil restraint on PVC pipes subjected to lateral movement, while the yield displacement for PVC pipes is observed to be much greater than the ALA (2005) recommendation. Also, the calculation method of Nyman (1984) is unable to provide close estimations of peak soil restraint on PVC pipes for different loading angles. A new calculation method is proposed, forming a design chart that can accurately predict the peak soil restraint to different movement directions.

埋地管道是重要生命线系统不可或缺的一部分，它横跨广阔的地域，输送供人类使用的流体产品。由于地质灾害，管道可能会受到不同方向的横向位移，即管道轴线法线方向的位移。然而，关于柔性管道在受到这种位移时的响应的实验研究报告却很有限。在本研究中，为了更好地了解柔性管道与土壤的相互作用，对干燥沙土中的聚氯乙烯（PVC）管道进行了 14 次大规模多方向拖曳试验。试验发现，土壤约束、中跨挠度、圆周应变和纵向应变随管道埋入深度的增加而增加，随加载角度的增加而减小。据观察，ALA（2005 年）的设计指南在很大程度上高估了 PVC 管道在横向移动时的土壤约束峰值，而据观察，PVC 管道的屈服位移远大于 ALA（2005 年）的建议值。此外，Nyman（1984）的计算方法也无法对不同加载角度下 PVC 管材的土壤约束峰值进行精确估算。本文提出了一种新的计算方法，形成了一个设计图表，可以准确预测不同运动方向的土壤约束峰值。

{"title":"Response of flexible pipes buried in sand under multi-directional movement: understanding fault-pipeline interaction","authors":"","doi":"10.1016/j.soildyn.2024.108978","DOIUrl":"10.1016/j.soildyn.2024.108978","url":null,"abstract":"<div><div>Buried pipelines are an integral part of critical lifeline systems, and span across wide geographic areas to convey fluid products for human use. Due to geohazards, pipelines could be subjected to transverse displacements in different directions, i.e., displacements normal to the pipe axis. However, limited experimental studies have been reported on the response of flexible pipes when subjected to such displacements. In this study, fourteen large-scale multi-directional dragging tests were conducted on polyvinyl chloride (PVC) pipes in dry sand to promote a better understanding of flexible pipe-soil interaction. The soil restraint, midspan deflection, circumferential strain, and longitudinal strain are found to increase with the pipe embedment depth and decrease with the loading angle. It is observed that the design guidelines of ALA (2005) largely overestimate the peak soil restraint on PVC pipes subjected to lateral movement, while the yield displacement for PVC pipes is observed to be much greater than the ALA (2005) recommendation. Also, the calculation method of Nyman (1984) is unable to provide close estimations of peak soil restraint on PVC pipes for different loading angles. A new calculation method is proposed, forming a design chart that can accurately predict the peak soil restraint to different movement directions.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311724","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}

引用次数: 0

Nonlinear seismic performance of offshore wind turbines on hybrid pile-bucket foundation in sand: Combined earthquake and wind-wave loads 沙中混合桩-桶基础上海上风力涡轮机的非线性抗震性能：地震和风浪综合荷载

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-09-20 DOI: 10.1016/j.soildyn.2024.108981

Offshore wind turbines (OWTs) are gaining prominence worldwide, and the hybrid pile-bucket foundation, which combines a monopole and a bucket, has emerged as a noteworthy development. In this study, a 3-D numerical model for the 5-MW OWT was constructed utilizing the OpenSees platform. The dynamic characteristics of the sand was modeled with the PDMY02 constitutive model and the soil was discretized using brick u-p elements. To investigate the dynamic behavior of the OWT in an actual marine environment, the coupled model was subjected to dynamic loadings, encompassing waves, wind, and earthquake. Two seismic motions with different frequency components were considered, respectively. The study focused on exploring the impacts of key influencing factors on the OWT rotation, tower-top acceleration development and spatiotemporal distribution of excess pore water pressure ratio (EPWPR). These factors include dynamic load combinations, earthquake intensity, soil relative density, wind speed, angle between load directions, and pile length. It is revealed that the inclination angle of offshore wind turbines (OWTs) may exceed the allowable threshold under specific conditions of load combinations, seismic motion inputs, and seabed conditions. Thus, it is suggested to appropriately consider the effects of wind and wave actions in the seismic analysis of OWTS.

海上风力涡轮机（OWT）在全球范围内的地位日益突出，而结合了单极杆和吊桶的混合桩-吊桶基础已成为一个值得关注的发展方向。在本研究中，利用 OpenSees 平台构建了 5-MW OWT 的三维数值模型。沙的动态特性采用 PDMY02 构成模型建模，土壤采用砖 u-p 元素离散。为了研究 OWT 在实际海洋环境中的动态行为，对耦合模型进行了动态载荷试验，包括海浪、风和地震。分别考虑了两种不同频率成分的地震运动。研究重点是探讨主要影响因素对 OWT 旋转、塔顶加速度发展和过剩孔隙水压力比（EPWPR）时空分布的影响。这些因素包括动荷载组合、地震烈度、土壤相对密度、风速、荷载方向夹角和桩长。研究表明，在特定的荷载组合、地震运动输入和海床条件下，海上风力涡轮机（OWT）的倾角可能会超过允许阈值。因此，建议在 OWTS 地震分析中适当考虑风和波浪作用的影响。

{"title":"Nonlinear seismic performance of offshore wind turbines on hybrid pile-bucket foundation in sand: Combined earthquake and wind-wave loads","authors":"","doi":"10.1016/j.soildyn.2024.108981","DOIUrl":"10.1016/j.soildyn.2024.108981","url":null,"abstract":"<div><p>Offshore wind turbines (OWTs) are gaining prominence worldwide, and the hybrid pile-bucket foundation, which combines a monopole and a bucket, has emerged as a noteworthy development. In this study, a 3-D numerical model for the 5-MW OWT was constructed utilizing the OpenSees platform. The dynamic characteristics of the sand was modeled with the PDMY02 constitutive model and the soil was discretized using brick u-p elements. To investigate the dynamic behavior of the OWT in an actual marine environment, the coupled model was subjected to dynamic loadings, encompassing waves, wind, and earthquake. Two seismic motions with different frequency components were considered, respectively. The study focused on exploring the impacts of key influencing factors on the OWT rotation, tower-top acceleration development and spatiotemporal distribution of excess pore water pressure ratio (EPWPR). These factors include dynamic load combinations, earthquake intensity, soil relative density, wind speed, angle between load directions, and pile length. It is revealed that the inclination angle of offshore wind turbines (OWTs) may exceed the allowable threshold under specific conditions of load combinations, seismic motion inputs, and seabed conditions. Thus, it is suggested to appropriately consider the effects of wind and wave actions in the seismic analysis of OWTS.</p></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142272220","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}

引用次数: 0

Simplified analytical solution of bell-spigot jointed ductile iron pipelines crossing normal faults 钟形插销连接球墨铸铁管道穿越正常断层的简化分析解决方案

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-09-17 DOI: 10.1016/j.soildyn.2024.108955

Bell-spigot jointed ductile iron pipelines are increasingly used, which are highly susceptible to permanent ground deformation. It is necessary to predict their responses under normal fault conditions. This investigation presents an analytical approach that simplifies the pipeline as a beam-type structure resting on discrete Winkler foundation comprising discrete springs, connected by shear and torsional springs at the bell-spigot joints, which is solved by the finite difference method. Comparisons of pipe deflection and joint rotation with the results from two full-scale experiments confirm the effectiveness of this method. Parametric analysis is conducted with respect to soil modulus, location of peak curvature, burial condition, pipe diameter, and joint rotational stiffness. It is found that increase in soil modulus can deteriorate the deformation of pipe bodies. Concentration of shear zones intensifies the responses of both pipeline segments and bell-spigot joints. For deeply buried jointed pipelines, less compacted backfills can reduce the soil-pipe interaction forces, mitigating the detrimental impact of fault rupture. A concept of relative joint-pipe stiffness ratio, R, is introduced to describe different joint rotational stiffness, identifying the threshold of R = 10 % for transition between jointed and continuous pipelines. Considering different failure limits, joint rotation failure always occurs earlier than pipe bending failure.

Bell-spigot 接头球墨铸铁管道的应用越来越广泛，这种管道极易受到永久性地面变形的影响。有必要预测其在正常故障条件下的响应。本研究提出了一种分析方法，将管道简化为由离散弹簧组成的梁式结构，支撑在离散的温克勒地基上，在钟形插销接头处由剪切和扭转弹簧连接，并采用有限差分法求解。管道挠度和接头旋转与两个全尺寸实验结果的比较证实了该方法的有效性。对土壤模量、峰值曲率位置、埋设条件、管道直径和接头旋转刚度进行了参数分析。结果发现，土壤模量的增加会使管体变形恶化。剪切区的集中会加剧管道段和钟形插销接头的响应。对于深埋的连接管道，较少压实的回填土可减少土壤与管道之间的相互作用力，从而减轻断层破裂的不利影响。引入了接头-管道相对刚度比 R 的概念来描述不同的接头旋转刚度，并确定 R = 10 % 为接头管道和连续管道之间的过渡阈值。考虑到不同的失效极限，接头旋转失效总是早于管道弯曲失效。

{"title":"Simplified analytical solution of bell-spigot jointed ductile iron pipelines crossing normal faults","authors":"","doi":"10.1016/j.soildyn.2024.108955","DOIUrl":"10.1016/j.soildyn.2024.108955","url":null,"abstract":"<div><p>Bell-spigot jointed ductile iron pipelines are increasingly used, which are highly susceptible to permanent ground deformation. It is necessary to predict their responses under normal fault conditions. This investigation presents an analytical approach that simplifies the pipeline as a beam-type structure resting on discrete Winkler foundation comprising discrete springs, connected by shear and torsional springs at the bell-spigot joints, which is solved by the finite difference method. Comparisons of pipe deflection and joint rotation with the results from two full-scale experiments confirm the effectiveness of this method. Parametric analysis is conducted with respect to soil modulus, location of peak curvature, burial condition, pipe diameter, and joint rotational stiffness. It is found that increase in soil modulus can deteriorate the deformation of pipe bodies. Concentration of shear zones intensifies the responses of both pipeline segments and bell-spigot joints. For deeply buried jointed pipelines, less compacted backfills can reduce the soil-pipe interaction forces, mitigating the detrimental impact of fault rupture. A concept of relative joint-pipe stiffness ratio, <em>R</em>, is introduced to describe different joint rotational stiffness, identifying the threshold of <em>R</em> = 10 % for transition between jointed and continuous pipelines. Considering different failure limits, joint rotation failure always occurs earlier than pipe bending failure.</p></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142238224","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}

引用次数: 0