Soil Dynamics and Earthquake Engineering最新文献

A method to truncate elastic half-plane for soil–structure interaction analysis under moving loads and its implementation to ABAQUS 移动荷载下土体与结构相互作用分析的弹性半平面截断方法及其在 ABAQUS 中的应用

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-17 DOI: 10.1016/j.soildyn.2024.109015

Moving loads appear in many half-plane problems, including analyses involving highway or railway bridges, culverts, and embankments. Current modeling approaches are mostly analytical, which provide only limited utility in practical problems featuring embedded or supported scatterers (e.g., a tunnel). Basic applications of fully numerical/discrete approaches (e.g., the finite element method) are also complicated because of the moving inbound load(s). One approach is to use a very large domain so that the wavefield reaches a steady state prior to any significant interaction of the moving loads with the local region containing the scatterer. This scenario elevates the computational burden to impractically high levels. In the present study, we devise an approach featuring Perfectly-Matched-Layers (PMLs) and the Domain Reduction Method (DRM) for a linear elastic half-plane, which enables drastic reductions in the domain size without sacrificing accuracy. The effective nodal forces at the boundary of the truncated local domain are computed a priori for the far free-field problem. Both the scattered and otherwise outbound waves are absorbed by the PMLs. The DRM approach and the PMLs are implemented together in commercial software ABAQUS—the former with a stand-alone code that modifies the ABAQUS input file and the latter through a user-defined element (UEL) subroutine. The accuracy of the method and its implementation is verified for homogeneous half-planes with and without a rectangle-shaped hollow zone under a concentrated moving load. We also present a parametric study involving a variety of scatterer geometries, embedment depths, and load speeds. The results indicate the veracity and the utility of the DRM and PML implementations for moving loads on half-plane.

移动荷载出现在许多半平面问题中，包括涉及公路或铁路桥梁、涵洞和路堤的分析。目前的建模方法大多是分析方法，对于具有嵌入式或支撑式散射体（如隧道）的实际问题，这种方法只能提供有限的效用。完全数值/离散方法（如有限元法）的基本应用也因为移动的入站荷载而变得复杂。一种方法是使用一个非常大的域，使波场在移动载荷与包含散射体的局部区域发生明显相互作用之前达到稳定状态。这种方案会将计算负担提升到不切实际的高度。在本研究中，我们为线性弹性半平面设计了一种以完美楔形层（PMLs）和域缩减法（DRM）为特征的方法，它能在不牺牲精度的情况下大幅缩小域尺寸。针对远自由场问题，先验计算了截断局部域边界的有效节点力。散射波和出射波都会被 PML 吸收。DRM 方法和 PML 都是在商业软件 ABAQUS 中实现的--前者是通过修改 ABAQUS 输入文件的独立代码实现的，后者是通过用户自定义元素 (UEL) 子程序实现的。在集中移动载荷作用下，我们对带有和不带矩形空心区的均质半圆平面验证了该方法的准确性及其实现。我们还提出了一项参数研究，涉及各种散射体几何形状、嵌入深度和载荷速度。结果表明了 DRM 和 PML 实现在半平面上移动载荷的真实性和实用性。

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引用次数: 0

Study on deformation patterns of tunnel isolation layers and seismic response of a shield tunnel 隧道隔离层变形模式及盾构隧道地震响应研究

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-17 DOI: 10.1016/j.soildyn.2024.108998

Tunnel seismic isolation is an effective measure to reduce the seismic response of tunnels; however, the unclear mechanism limits the popularization and application of this measure. In this study, the deformation patterns of tunnel seismic isolation were investigated using theoretical analyses and shaking-table experiments. The analytical solution for the dynamic response of the seismic isolation tunnel under SH-wave incidence was derived using the wave-function expansion method. A novel loading device based on the reaction-displacement method was used to study the mechanism of the tunnel seismic isolation layer. It was found that the seismic isolation layer helped reduce and spread the deformation from the outer surface to the inner surface, effectively minimizing the deformation affecting the lining. The DSCF response of the lining is subsequently reduced. Moreover, the installation of seismic isolation did not result in a significant alteration in the acceleration response of the tunnel. These results provide a reference for the seismic isolation design of tunnels.

隧道隔震是降低隧道地震反应的有效措施，但由于其机理不清，限制了该措施的推广和应用。本研究利用理论分析和振动台实验研究了隧道隔震的变形模式。利用波函数展开法得出了隔震隧道在 SH 波入射下的动态响应解析解。利用基于反作用位移法的新型加载装置研究了隧道隔震层的机理。研究发现，隔震层有助于减少和分散从外表面到内表面的变形，从而有效地将影响衬砌的变形降到最低。衬砌的 DSCF 反应随之减小。此外，隔震层的安装并未导致隧道加速度响应的显著改变。这些结果为隧道的隔震设计提供了参考。

引用次数: 0

High robust eddy current tuned tandem mass dampers-inerters for structures under the ground acceleration 用于地面加速度下结构的高稳健性涡流调谐串联质量阻尼器-插入器

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-17 DOI: 10.1016/j.soildyn.2024.109040

In this work, a novel eddy current tuned tandem mass dampers-inerters, referred to as EC-TTMDI is proposed, a theoretical analysis model of the vibration control mechanism is established, and parameterized analysis and design are conducted using the intelligent optimization algorithm. This model is the single-degree-of-freedom (SDOF) structure with EC-TTMDI subjected to Gaussian white noise base excitation. Specifically, the expression for the displacement variance of the SDOF structure-EC-TTMDI system was firstly obtained with resorting to both the equivalent linearization of eddy current damper (ECD) and residue theorem. The optimization objective function was then defined as minimization of the displacement variance, which is product of the white noise intensity and the square of H₂ norm of the model transfer function. Employing the pattern-search algorithm, the variation trends of the objective function and the optimum design parameters were subsequently scrutinized. The vibration damping mechanism of EC-TTMDI is then revealed in terms of control effectiveness, robustness, structural frequency response, suppression bandwidth, and stroke. Finally, the time history response analysis of the SDOF structure-EC-TTMDI system subjected to the near-field impulse, near-field non-impulse, and far-field earthquakes was conducted to further confirm the performance superiority of EC-TTMDI. Results demonstrates that EC-TTMDI offers higher robustness and better control effectiveness compared to TTMDI and TMDI. Furthermore, EC-TTMDI features the damping force limiting characteristic, which enhances the integrity and reliability of TTMDI.

本文提出了一种新型涡流调谐串联质量阻尼器-插入器（简称 EC-TTMDI），建立了振动控制机制的理论分析模型，并利用智能优化算法进行了参数化分析和设计。该模型为带有 EC-TTMDI 的单自由度（SDOF）结构，受到高斯白噪声基本激励。具体来说，首先利用电涡流阻尼器（ECD）的等效线性化和残差定理得到了 SDOF 结构-EC-TTMDI 系统的位移方差表达式。然后将优化目标函数定义为位移方差最小化，位移方差是白噪声强度与模型传递函数 H2 准则平方的乘积。采用模式搜索算法，对目标函数的变化趋势和最佳设计参数进行了仔细研究。然后，从控制效果、鲁棒性、结构频率响应、抑制带宽和行程等方面揭示了 EC-TTMDI 的减振机理。最后，对 SDOF 结构-EC-TTMDI 系统进行了近场脉冲、近场非脉冲和远场地震的时间历程响应分析，进一步证实了 EC-TTMDI 的性能优越性。结果表明，与 TTMDI 和 TMDI 相比，EC-TTMDI 具有更高的鲁棒性和更好的控制效果。此外，EC-TTMDI 还具有阻尼力限制特性，从而提高了 TTMDI 的完整性和可靠性。

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引用次数: 0

Simplified site response analysis for regional seismic risk assessments 用于区域地震风险评估的简化场地响应分析

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-16 DOI: 10.1016/j.soildyn.2024.109022

Seismic risk assessment on a regional scale requires an estimation of ground motion intensity and its spatial variation over large geographical areas. This task is particularly challenging in the presence of very soft soil deposits where significant amplification occurs at specific frequencies that are often referred to as local resonances. It is often not feasible to conduct a nonlinear site response analysis at thousands of sites of interest across a region such as an urban area due to the computational effort involved and the required detailed information on soil profiles at each site. Thus, in regional seismic risk analyses the hazard is typically represented by a field of response spectral ordinates estimated by ground motion models. This study proposes a simplified site response analysis procedure to improve the characterization of spectral ordinates to be used in regional seismic risk assessments. In the proposed procedure, reduced-order models are used to conduct site response analysis using very few parameters to transform response spectra at rock outcrop into response spectra at the surface of each of the sites. A particular emphasis is given to soft-soil sites characterized by low shear-wave velocities overlaid on rock or firm soils. A non-uniform continuous shear beam model with a parabolic variation of shear modulus along the depth and modal damping is used in combination with Random Vibration Theory. It is shown that the proposed approach provides better estimates than those of ground motion models or physics-based ground motion simulation models which often cannot capture the local resonances. Site-specific validation of the shear beam model and overall simplified site response analysis is performed at four soft-soil sites in San Francisco, California. Despite its simplicity, it is shown that the proposed procedure adequately captures the amplitudes and spectral shapes of the motions. It is also shown that in conjunction with ground motion models or physics-based models, the proposed simplified site response analysis procedure can be used to efficiently simulate the seismic hazard on a regional scale through an example of a regional seismic hazard analysis of 160 softer soil sites in Downtown San Francisco during the Loma Prieta earthquake.

区域范围的地震风险评估需要估算地动强度及其在大面积地理区域内的空间变化。在存在非常松软的土壤沉积的情况下，这项任务尤其具有挑战性，因为在特定频率下会出现明显的放大现象，这通常被称为局部共振。由于计算工作量大，而且每个地点都需要详细的土壤剖面信息，因此在城市地区等区域内对数千个相关地点进行非线性场地响应分析通常是不可行的。因此，在区域地震风险分析中，通常用地动模型估算的响应谱序数场来表示危险。本研究提出了一种简化的场地响应分析程序，以改进区域地震风险评估中使用的频谱序号的特征描述。在建议的程序中，使用简化阶模型进行场地响应分析，使用极少的参数将岩石露头处的响应谱转化为每个场地表面的响应谱。特别强调的是软土场地，其特点是岩石或坚硬土壤上的剪切波速度较低。结合随机振动理论，使用了剪切模量沿深度抛物线变化和模态阻尼的非均匀连续剪切梁模型。结果表明，与通常无法捕捉局部共振的地面运动模型或基于物理的地面运动模拟模型相比，所提出的方法能提供更好的估算结果。在加利福尼亚州旧金山的四个软土场地对剪力梁模型和整体简化场地响应分析进行了特定场地验证。结果表明，尽管程序简单，但所建议的程序能够充分捕捉到运动的振幅和频谱形状。此外，通过对洛马普列塔地震期间旧金山市中心 160 个软土场地进行区域地震危害分析的实例还表明，结合地面运动模型或基于物理的模型，所提出的简化场地响应分析程序可用于有效模拟区域范围内的地震危害。

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引用次数: 0

Long-term effect of soil settlement on lateral dynamic responses of end-bearing friction pile 土壤沉降对端承式摩擦桩侧向动力响应的长期影响

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-16 DOI: 10.1016/j.soildyn.2024.109041

This paper presents a closed-form solution to evaluate the lateral dynamic responses of pile foundation adjacent to superficial surcharge. The equilibrium equation of soil is analyzed using continuum solutions, and the Euler-Bernoulli beam theory is employed to model the pile. The consolidation settlement of surrounding soil induced by the superficial surcharge is determined by Terzaghi's consolidation theory. The lateral soil resistance is formulated using potential functions, and the dynamic responses of the end-bearing friction pile are subsequently obtained by considering the vertical load and skin friction. Our results are compared with analytical approaches from previous literature to validate the effectiveness of the present solution. The evolutions of lateral dynamic responses of pile foundation are systematically analyzed. It is suggested that the superficial surcharge influences the distribution of skin friction of the pile foundation, thereby altering its lateral dynamic responses. This phenomenon does not manifest immediately but demonstrates significant long-term effects during the consolidation settlement of surrounding soil.

本文提出了一种闭式求解方法，用于评估邻近表层附加荷载的桩基侧向动力响应。土的平衡方程采用连续解进行分析，桩的模型采用欧拉-伯努利梁理论。表层附加荷载引起的周围土壤固结沉降由 Terzaghi 的固结理论确定。侧向土体阻力采用势函数计算，随后通过考虑垂直荷载和表皮摩擦力得出端承摩擦桩的动态响应。我们的结果与之前文献中的分析方法进行了比较，以验证本解决方案的有效性。系统分析了桩基横向动力响应的演变。研究表明，表层附加荷载会影响桩基表层摩擦力的分布，从而改变桩基的侧向动力响应。这种现象不会立即显现，但在周围土壤固结沉降过程中会产生显著的长期影响。

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引用次数: 0

A PSHA for Mexico City based solely in Fourier-based GMM of the response spectra 完全基于傅里叶响应谱 GMM 的墨西哥城 PSHA 系统

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-15 DOI: 10.1016/j.soildyn.2024.109025

A key component of any probabilistic seismic hazard analysis (PSHA) is the capability of predicting ground motion intensities for future earthquakes with different characteristics and occurrence frequencies. Ground motion models (GMMs) have been the preferred tools to predict, in a probabilistic manner, the size of the ground motion as a function of the earthquake's rupture parameters (i.e., location, depth, orientation of the rupture plane, rupture area, and rupture shape, among others). For this purpose, two different approaches have been used in PSHA practice. The first one, widely used and with hundreds of available models, are semi-empirical derivations of GMMs for response spectral values. The second one, which is less used in professional practice, requires the development of the predicting model for the Fourier amplitude spectrum (FAS) and the duration of the strong motion, to convert them into response spectral values through random vibration theory (RVT). The second approach, although computationally complex, should be preferred when site-effects are considered in the PSHA since these can be incorporated in a more efficient and theoretically correct way. Also, this second approach allows estimating hazard levels for different damping ratios and other hazard intensity measures such as peak ground velocity (PGV) and peak ground displacement (PGD) straightforward. This paper shows the methodology and results of a PSHA for Mexico City, a place with well-known existence and relevance of site-effects, carried out exclusively using Fourier-based GMMs, developed to be representative for the different types of earthquakes that contribute to earthquake hazard in the city (i.e., interface, intraslab, and crustal). The strategy to estimate ground motions in Mexico City consists in obtaining FAS-based ground motion models for a reference firm ground station and multiplying the computed FAS by an empirical transfer function that describes the frequency-dependent amplification factors between the reference station and the soft site of interest.

任何概率地震灾害分析（PSHA）的一个关键组成部分都是能够预测具有不同特征和发生频率的未来地震的地动强度。地震动模型（GMM）是以概率方式预测地震动大小的首选工具，它是地震破裂参数（即位置、深度、破裂面方向、破裂面积和破裂形状等）的函数。为此，在 PSHA 实践中使用了两种不同的方法。第一种方法应用广泛，有数百种可用模型，是响应谱值 GMM 的半经验推导。第二种方法在专业实践中使用较少，需要开发傅立叶振幅谱（FAS）和强运动持续时间的预测模型，通过随机振动理论（RVT）将其转换为响应谱值。第二种方法虽然计算复杂，但在 PSHA 中考虑场地效应时应优先采用，因为可以以更有效和理论上更正确的方式纳入这些效应。此外，第二种方法还可以直接估算不同阻尼比和其他危险强度指标（如峰值地表速度 (PGV) 和峰值地表位移 (PGD)）的危险等级。本文展示了墨西哥城 PSHA 的方法和结果，墨西哥城是一个众所周知存在场地效应且与场地效应相关的地方，PSHA 完全采用基于傅立叶的 GMM，其开发目的是代表造成墨西哥城地震灾害的不同地震类型（即界面地震、台内地震和地壳地震）。估算墨西哥城地动的策略包括：为一个基准坚固地面站获取基于 FAS 的地动模型，并将计算出的 FAS 乘以一个经验传递函数，该函数描述了基准站和相关软地点之间随频率变化的放大系数。

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引用次数: 0

Dynamic analysis for horizontal vibration of piles in layered Pasternak soils considering secondary ground waves 考虑次生地波的帕斯捷尔纳克层状土中桩基水平振动动态分析

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-15 DOI: 10.1016/j.soildyn.2024.109026

To comprehensively investigate the effects of secondary ground waves (SGWs) induced by the vibration of receiver piles (RPs) in layered soils on the pile-pile horizontal vibration (PPHV), a simplified mechanical model for frequency-domain analysis of PPHV is proposed. This proposed model is based on layered Pasternak soils and elastic Euler-Bernoulli beam theory, incorporating the effects of axial loads and SGW. Firstly, the horizontal displacements (HDs) and the internal forces of the source pile (SP) are obtained using the differential transformation method combined with the continuity boundary conditions (BCs) at the pile-soil interface. Secondly, considering the influence of the vibration of the SP on the RP, a horizontal vibration analysis model for the RP is established, followed by the derivation of an analytical solution for the horizontal dynamic response (HDR). Furthermore, to consider the influence of SGWs induced by the vibration of the RP on the HDR of the SP, an improved analytical solution for the HDR of the RP is obtained. Finally, based on the definition of the dynamic interaction factor, the pile-pile horizontal dynamic interaction factor (PPHDIF) is derived and its rationality is validated by comparisons with existing solutions. Parametric analyses are performed to explore the effects of soil shear deformation, pile-soil modulus ratio, and axial loads on the PPHDIF. The results provide theoretical guidance and references for the dynamic design of pile groups in engineering practice.

为全面研究层状土中接收桩（RPs）振动引起的次生地波（SGWs）对桩-桩水平振动（PPHV）的影响，本文提出了一种用于频域分析 PPHV 的简化力学模型。该模型基于层状帕斯捷尔纳克土和弹性欧拉-伯努利梁理论，并考虑了轴向荷载和 SGW 的影响。首先，利用微分变换法结合桩土界面上的连续性边界条件（BCs）获得源桩（SP）的水平位移（HDs）和内力。其次，考虑到 SP 的振动对 RP 的影响，建立了 RP 的水平振动分析模型，然后推导出水平动力响应 (HDR) 的解析解。此外，为了考虑 RP 振动引起的 SGW 对 SP 的 HDR 的影响，还获得了 RP HDR 的改进分析解。最后，根据动态相互作用系数的定义，得出了桩-桩水平动态相互作用系数（PPHDIF），并通过与现有解决方案的比较验证了其合理性。通过参数分析，探讨了土体剪切变形、桩土模量比和轴向荷载对 PPHDIF 的影响。研究结果为工程实践中的桩群动态设计提供了理论指导和参考。

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引用次数: 0

Mitigation of numerical dispersion in seismic data in spectral domain with neural networks 利用神经网络减轻频谱域地震数据的数值离散性

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-14 DOI: 10.1016/j.soildyn.2024.109028

Seismic modeling has various engineering applications, including exploration seismology, seismic monitoring of greenhouse gas sequestration, and earthquake engineering. However, it is computationally demanding if conventional grid-based methods are used due to the mathematical restrictions on the grid size. This research presents an approach combining conventional grid-based seismic modeling with machine learning, where the solution is simulated using a coarse grid with high numerical error. Then, it is corrected by the numerical dispersion mitigation neural network (NDM-net). Previously, the NDM-net was applied to the simulated seismic data in the time domain, where either large datasets are treated, leading to increased training time and memory usage, or the patches are constructed, leading to accuracy reduction. This paper focuses on applying the NDM-net in the frequency domain, where only low frequencies of about 10% to 30% of spectra are used. It is possible due to the band-limited nature of the source’s impulse. Thus, the frequency domain NDM-net allows for preserving the original NDM-net’s high accuracy with reduced computational resources and time demand, improving the NDM-net performance and making it applicable to large-scale 3D problems. We illustrate the applicability of the suggested approach on three velocity models representing completely different geological environments where NDM-net allows to speed up seismic modeling by a factor of 2.5 to 4 in comparison to fine-grid modeling.

地震建模有多种工程应用，包括地震勘探、温室气体封存的地震监测和地震工程。然而，由于对网格大小的数学限制，如果使用传统的网格方法，计算要求很高。本研究提出了一种将传统基于网格的地震建模与机器学习相结合的方法，即使用数值误差较大的粗网格模拟求解。然后，通过数值分散减缓神经网络（NDM-net）对其进行修正。此前，NDM-net 被应用于时域的模拟地震数据，要么处理大型数据集，导致训练时间和内存占用增加，要么构建补丁，导致精度降低。本文的重点是在频域中应用 NDM 网，在频域中仅使用约 10% 至 30% 的低频频谱。这是因为声源脉冲具有频带限制的特性。因此，频域 NDM 网可以在减少计算资源和时间需求的情况下保持原始 NDM 网的高精度，从而提高 NDM 网的性能，并使其适用于大规模三维问题。我们在代表完全不同地质环境的三个速度模型上说明了所建议方法的适用性，与细网格建模相比，NDM 网可将地震建模速度提高 2.5 至 4 倍。

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引用次数: 0

Seismic retrofitting of GFRP-reinforced concrete columns using precast UHPC plates 使用预制超高性能混凝土板对 GFRP 加固混凝土柱进行抗震改造

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-14 DOI: 10.1016/j.soildyn.2024.109024

With the increasing utilization of fiber-reinforced polymer (FRP) bars in concrete structures, the issue of retrofitting damaged FRP-reinforced concrete (FRP-RC) structures will emerge. However, limited research is available on the seismic performance of damaged FRP-RC structures after retrofitting. In this study, cyclic tests were conducted to evaluate the efficiency of precast ultra-high performance concrete (UHPC) plates in retrofitting the seismic performance of GFRP-RC columns with continuous or lap-spliced GFRP bars. Three GFRP-RC columns, among which one column with lap-spliced details was strengthened with precast UHPC plates, and the other two columns were retrofitted with precast UHPC plates combined with NSM after simulated seismic damage testing. To compare the retrofitting efficiency of this method for GFRP-RC and steel-RC columns, a previous study on steel-RC columns retrofitted with UHPC was incorporated. For the pre-damaged GFRP-RC columns after retrofitting with precast UHPC plates combined with NSM, the peak load experienced an increase of 76 %–79 %, and the ductility was complete restored. The failure modes of strengthened or retrofitted GFRP-RC columns differ from those of strengthened or retrofitted steel-RC columns. Further, the flexural strength of GFRP-RC columns and beams after being strengthened or retrofitted by UHPC can be predicted well based on the cross-section analysis model.

随着纤维增强聚合物（FRP）钢筋在混凝土结构中的应用越来越广泛，对受损的 FRP-RC 结构进行改造的问题也随之出现。然而，关于改造后受损 FRP-RC 结构抗震性能的研究还很有限。本研究进行了循环试验，以评估预制超高性能混凝土（UHPC）板在改造带有连续或搭接 GFRP 杆件的 GFRP-RC 柱抗震性能方面的效率。在三根 GFRP-RC 柱子中，一根采用搭接细节的柱子使用预制超高性能混凝土板进行加固，另外两根柱子在模拟地震破坏试验后使用预制超高性能混凝土板结合 NSM 进行改造。为了比较这种方法对 GFRP-RC 和钢-RC 柱的改造效率，还结合了之前对采用 UHPC 改造的钢-RC 柱的研究。对于预先损坏的 GFRP-RC 柱，在使用预制 UHPC 板结合 NSM 进行改造后，峰值载荷增加了 76 %-79%，延性也完全恢复。加固或改造后的 GFRP-RC 柱的破坏模式与加固或改造后的钢-RC 柱不同。此外，根据截面分析模型，可以很好地预测采用超高性能混凝土加固或改造后的 GFRP-RC 柱和梁的抗弯强度。

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引用次数: 0

Regional study of site effects on the high-frequency spectral-decay parameter 遗址对高频频谱衰减参数影响的区域研究

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-13 DOI: 10.1016/j.soildyn.2024.109030

The high-frequency spectral-decay parameter κ has been used in the field of engineering seismology for several decades. The zero-distance κ value (κ₀) is a site parameter in ground motion models and strong motion synthesis. Using surface-borehole pairs of strong motion records from the strong-motion seismograph network KiK-net, we explored the effect of site soil on κ₀, specifically the contribution from ground motion directionality. In the target area (138°E−143°E, 36°N–40°N), and records from earthquakes at 50 pairs of stations were collected. All horizontal orthogonal records were rotated from 0° to 180° with an increment of 10° to capture the difference between the average κ₀ on two horizontal components and the median value of the rotated κ₀ at surface and borehole stations. The same process was applied to Δκ₀, the difference between surface station κ₀ and borehole station κ₀, to measure the contribution by soil column. The nonlinear behavior of soils led to large shear strains, reduced stiffness, and decreased resonance frequency. Thus, the effect of soil nonlinearity on κ is investigated. In the same area, strong ground motion records with peak ground acceleration >100 cm/s² were selected to identify the soil nonlinearity by the moving time window deconvolution method, and the temporal variation of time-average shear wave velocity and κ at the 50 surface stations were assessed.

高频频谱衰减参数 κ 已在工程地震学领域应用了几十年。零距离κ值（κ0）是地动模型和强震合成中的场地参数。利用强震动地震仪网络 KiK-net 的地表-钻孔强震动记录对，我们探索了场地土壤对 κ0 的影响，特别是地动方向性的贡献。我们在目标区域（138°E-143°E，36°N-40°N）收集了 50 对台站的地震记录。所有水平正交记录以 10° 为增量从 0° 旋转到 180°，以捕捉两个水平分量上平均 κ0 与地面站和钻孔站旋转后 κ0 中值之间的差异。对地表站 κ0 和钻孔站 κ0 之间的差值 Δκ0 也采用了同样的方法，以测量土柱的贡献。土壤的非线性行为导致剪切应变较大、刚度降低和共振频率降低。因此，研究了土壤非线性对 κ 的影响。在同一地区，选取峰值地面加速度为 100 cm/s2 的强地面运动记录，采用移动时间窗解卷法识别土壤非线性，并评估了 50 个地面站的时间平均剪切波速度和 κ 的时间变化。

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引用次数: 0