Soil Dynamics and Earthquake Engineering最新文献_第3页

Rapid and automated seismic design of cable restrainer for simply supported bridges crossing fault rupture zones using explainable machine learning 利用可解释的机器学习，为跨越断层破裂带的简支桥梁快速自动设计缆索约束装置

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-09 DOI: 10.1016/j.soildyn.2024.109011

Earthquakes in recent decades have demonstrated that fault-crossing simply supported bridges were susceptible to damage caused by the fault-induced permanent ground dislocation. Cable restrainer can potentially reduce the relative displacement of bridge spans, but the current seismic design method for restrainer is time-consuming and labor-intensive. This study aims to develop a rapid and automated seismic design method for cable restrainer using explainable machine learning (ML) models. To do this, a large database was first generated based on the current design approach. ML algorithms were utilized to develop classification models to determine the design classes and then regression models to estimate the restrainer stiffness for the fault-crossing bridges. Furthermore, SHapley Additive exPlanations (SHAP) analysis was utilized to provide interpretations for the best regression model. In particular, an empirical formula and two explainable prediction models by combining the empirical formula with simplified ML models were finally proposed to facilitate the design for engineers. Results show that the proposed design method can provide accurate and robust results of bridge restrainers. Within the method, artificial neural network was selected among nine ML models, because of its highest accuracy for both classification and regression. The SHAP analysis reveals that, the allowable displacement has a negative nonlinear effect, while permanent ground dislocation and initial relative displacement present positive nonlinear effects. The proposed empirical formula for restrainer design can provide conservative estimations with an accuracy of 79 %, whereas the proposed explainable prediction models have a high accuracy of 94 % and are significantly efficient and user-friendly.

近几十年来发生的地震表明，跨越断层的简支桥梁很容易受到断层引起的永久地表位移的破坏。拉索约束装置有可能减少桥跨的相对位移，但目前的约束装置抗震设计方法耗时耗力。本研究旨在利用可解释的机器学习（ML）模型，开发一种快速、自动化的缆索约束抗震设计方法。为此，首先根据当前的设计方法生成了一个大型数据库。利用 ML 算法开发分类模型来确定设计类别，然后利用回归模型来估算跨断层桥梁的约束刚度。此外，还利用 SHapley Additive exPlanations（SHAP）分析法为最佳回归模型提供解释。特别是，通过将经验公式与简化的 ML 模型相结合，最终提出了一个经验公式和两个可解释的预测模型，以方便工程师进行设计。结果表明，所提出的设计方法可以为桥梁约束装置提供准确、稳健的结果。在该方法中，人工神经网络在分类和回归方面都具有最高的准确性，因此在九个 ML 模型中被选中。SHAP 分析表明，容许位移具有负非线性效应，而永久地面错位和初始相对位移则具有正非线性效应。所提出的约束装置设计经验公式可以提供保守的估计，准确率为 79%，而所提出的可解释预测模型的准确率高达 94%，并且非常高效和易于使用。

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引用次数: 0

Seismic failure analysis of a high arch dam-foundation multiple nonlinear coupling system 高拱坝-地基多重非线性耦合系统的地震破坏分析

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-07 DOI: 10.1016/j.soildyn.2024.109001

In this study, a high arch dam-foundation system model with more than ten million degrees of freedom was constructed. The model innovatively incorporates multiple nonlinear couplings of the strength failure of the dam body and stability failure of dam abutment blocks for the first time. A nonlinear dynamic response analysis of the coupling system was performed at different overload coefficients. The maximum damage depth-thickness ratio and sliding area ratio are proposed as performance evaluation indices. The failure mechanism of the model under strong earthquakes was elucidated. The residual displacement of the dam crest relative to the dam bottom in the stream direction is proposed as another performance evaluation index. Sudden changes and rapid growth are suggested as evaluation criteria to assess the ultimate seismic capacity of arch dams based on proposed multi-nonlinear coupled model. The results show that the strength failure of the dam body and stability failure of the dam abutments vary dynamically with the duration and intensity of the earthquake. Earthquake energy can be fully released by only one failure mode at low seismic intensity, whereas it is gradually released by both failure modes as the seismic intensity increases. The overload coefficient corresponding to the ultimate seismic capacity of the dam is concluded to be 2.0.

本研究构建了一个自由度超过 1000 万的高拱坝-地基系统模型。该模型首次创新性地加入了坝体强度破坏和坝基稳定性破坏的多重非线性耦合。在不同超载系数下，对耦合系统进行了非线性动态响应分析。提出了最大破坏深度厚度比和滑动面积比作为性能评价指标。阐明了模型在强震下的破坏机理。提出了坝顶相对于坝底在流向上的残余位移作为另一个性能评价指标。根据所提出的多非线性耦合模型，提出了突变和快速增长作为评估拱坝极限抗震能力的评价标准。结果表明，坝体的强度破坏和坝基的稳定性破坏随地震持续时间和烈度的变化而动态变化。在地震烈度较低时，只有一种破坏模式可以完全释放地震能量，而随着地震烈度的增加，两种破坏模式都会逐渐释放地震能量。与大坝极限抗震能力相对应的超载系数为 2.0。

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引用次数: 0

An enhanced hybrid approach for spatial distribution of seismic liquefaction characteristics by integrating physics-based simulation and machine learning 基于物理的模拟与机器学习相结合的地震液化特征空间分布增强型混合方法

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-07 DOI: 10.1016/j.soildyn.2024.109007

This study aims to propose an enhanced hybrid approach that combines physics-based simulation and machine learning to investigate the spatial distribution of seismic liquefaction characteristics. This innovative approach comprises two main components: Firstly, the physics-based frequency-wavenumber method is employed to construct the spatial-temporal field of ground motion in the study area, which provides ground motion quantities for assessing the liquefaction characteristic (e.g., liquefaction potential index) of the site. Subsequently, the seismic liquefaction parameters of the region are predicted using a machine learning (ML)-based SSA-XGBoost model. Due to the integration of physics-based simulation and machine learning techniques, which consider the effects of near-fault ground motion characteristics on seismic liquefaction, the proposed solution enables the evaluation of the spatial distribution of seismic liquefaction parameters under scenario earthquakes. In this study, the SSA-XGBoost model, constructed using the sparrow search algorithm (SSA) to automate and optimize the hyper-parameter tuning of the eXtreme gradient boosting (XGBoost), incorporates factors such as peak ground acceleration, magnitude scaling factor, ground water level, soil depth, vertical total overburden stress, vertical effective overburden stress, and fine content to evaluate their influence on liquefaction potential index. To demonstrate the effectiveness of the enhanced hybrid approach, the Jinnan district of Tianjin is taken as an example to evaluate liquefaction potential under various scenario earthquakes (M_w = 5.0, 5.5 and 6.0). The results show that the constructed SSA-XGBoost model has excellent predictive ability and is suitable for evaluating the liquefaction potential index of large-scale site soils. In the case of M_w 6.0 earthquake, most of the northern region of Jinnan district has the possibility of liquefaction, and some areas are seriously liquefied, and the liquefaction grade gradually decreases from the north to the south. These findings distinctly illustrate the spatial distribution of liquefaction characteristic parameters across the entire region, providing new insights and methods for similar studies and serving as a decision-making basis for the prevention and control of seismic liquefaction hazards.

本研究旨在提出一种增强型混合方法，结合基于物理的模拟和机器学习来研究地震液化特征的空间分布。这种创新方法包括两个主要部分：首先，采用基于物理的频率-波数方法构建研究区域的地动时空场，为评估场地的液化特征（如液化潜力指数）提供地动量。随后，使用基于机器学习（ML）的 SSA-XGBoost 模型对该地区的地震液化参数进行预测。由于基于物理的模拟与机器学习技术相结合，考虑了近断层地动特征对地震液化的影响，所提出的解决方案能够评估情景地震下地震液化参数的空间分布。在本研究中，利用麻雀搜索算法（SSA）构建了 SSA-XGBoost 模型，用于自动优化极限梯度提升（XGBoost）的超参数调整，将地表加速度峰值、震级缩放因子、地下水位、土层深度、垂直总覆土应力、垂直有效覆土应力和细粒含量等因素纳入模型，以评估它们对液化潜在指数的影响。为证明增强型混合方法的有效性，以天津市津南区为例，评估了各种情景地震（Mw = 5.0、5.5 和 6.0）下的液化潜力。结果表明，所构建的 SSA-XGBoost 模型具有出色的预测能力，适用于评估大型场地土壤的液化潜力指数。在 Mw 6.0 地震中，津南区北部大部分地区有液化的可能，部分地区液化严重，且液化等级由北向南逐渐降低。这些研究结果清楚地说明了全区液化特征参数的空间分布情况，为类似研究提供了新的认识和方法，也为防治地震液化灾害提供了决策依据。

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引用次数: 0

Theoretical relationship between the horizontal-to-vertical response and Fourier spectral ratios of ground motions 地动水平-垂直响应与傅里叶频谱比之间的理论关系

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-07 DOI: 10.1016/j.soildyn.2024.109010

Similar to the horizontal-to-vertical Fourier spectral ratio (HVF) of ground motions, the horizontal-to-vertical response spectral ratio (HVR) is a valuable tool for evaluating site effects. Although these two spectral ratios often exhibit similar behaviours, each possesses its own set of properties, prompting increased attention to their relationship. Previously, the relationship between HVF and HVR has been statistically investigated to explore which is more reasonable for predominant period estimation. However, the theoretical link between them remains unexplored. To clarify their theoretical relationship, in this study, an expression relating HVR to HVF based on random vibration theory was derived. The accuracy of the derived expression was confirmed through a comparison with the results obtained via direct numerical integration using real seismic records. Subsequently, based on the derived expression, the theoretical relationship between HVF and HVR was systematically explored. HVR was found to be the result of smoothing the square of the HVF, and the spectral window for this smoothing operation was determined using the Fourier amplitude spectrum of the vertical ground motion and the oscillator transfer function.

与地震动的水平-垂直傅立叶频谱比（HVF）类似，水平-垂直响应频谱比（HVR）也是评估场地效应的重要工具。虽然这两个频谱比经常表现出相似的行为，但各自都有自己的特性，这促使人们更加关注它们之间的关系。在此之前，曾对 HVF 和 HVR 之间的关系进行过统计调查，以探索哪一个在主要周期估算中更合理。然而，它们之间的理论联系仍未得到探讨。为了阐明它们之间的理论关系，本研究基于随机振动理论推导出了 HVR 与 HVF 的相关表达式。通过与使用真实地震记录进行直接数值积分得到的结果进行比较，确认了推导表达式的准确性。随后，根据推导出的表达式，系统地探讨了 HVF 和 HVR 之间的理论关系。研究发现 HVR 是平滑 HVF 平方的结果，并利用垂直地面运动的傅里叶振幅谱和振荡器传递函数确定了平滑操作的频谱窗口。

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引用次数: 0

Seismic response of a model soil-pile-bridge system in cohesive soil 粘性土中土桩桥模型系统的地震响应

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-05 DOI: 10.1016/j.soildyn.2024.109013

This paper investigates the dynamic response of a model pile-soil-bridge system subjected to seismic loading using a finite element model (FEM) developed in OpenSees. The numerical model is validated against shake table test data from a companion experimental study, which tested a piles-bridge model fabricated from organic glass. The bridge model comprised four piers, each supported by two-by-two pile groups, with edge piers featuring 60 × 60 mm rubber pads between the pier and deck. Two earthquake ground motions, El Centro and Tianjin, were applied at three intensity levels. The calculated and measured responses show good agreement. The validated FEM reveals that the El Centro earthquake typically induces higher acceleration and moment responses in structural elements compared to the Tianjin earthquake, while the Tianjin earthquake results in greater displacement responses. These findings highlight the impact of earthquake wave characteristics, such as predominant period, on the bridge system's response. Furthermore, the bending moments at the pier top for edge piers remain relatively consistent across different earthquake motions and intensity levels, indicating the role of rubber pads in mitigating seismic forces in the piers.

本文使用在 OpenSees 中开发的有限元模型（FEM）研究了模型桩-土-桥系统在地震荷载作用下的动态响应。数值模型根据配套实验研究的振动台测试数据进行了验证，该实验研究测试了用有机玻璃制作的桩-桥模型。桥梁模型由四个桥墩组成，每个桥墩由两两一组的桩组支撑，桥墩和桥面之间的边缘有 60 × 60 毫米的橡胶垫。在三个烈度水平上应用了埃尔中心罗和天津两种地震地面运动。计算和测量的响应显示出良好的一致性。经过验证的有限元模型显示，与天津地震相比，埃尔中心罗地震通常会在结构元件中产生更高的加速度和力矩响应，而天津地震则会产生更大的位移响应。这些发现凸显了地震波特征（如主要周期）对桥梁系统响应的影响。此外，在不同的地震运动和烈度水平下，边缘桥墩墩顶的弯矩保持相对一致，这表明橡胶垫在减轻桥墩地震力方面发挥了作用。

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引用次数: 0

Prediction on seismic performance levels of reinforced concrete beams by considering crack development 通过考虑裂缝发展预测钢筋混凝土梁的抗震性能等级

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-05 DOI: 10.1016/j.soildyn.2024.109006

The plastic rotation angle or deflection is typically used as the indicator to evaluate the earthquake-induced damage and classify the seismic performance levels of reinforced concrete (RC) beams. Herein, one of the most important issues is to determine the seismic performance level limits of RC beams. Whereas, different countries provided their specific method to determine the limit values by considering the loading-carrying capacity of RC beams, which could not be used to describe the earthquake-induced seepage of structures, especially for underground structures. Therefore, in this study, the seismic performance level limits of RC beams were predicted by using the machine learning methods and considering the development of cracks. Firstly, the seismic performance level limits of RC beams were presented after discussing the methods in different codes and the development of cracks. Then an earthquake performance test database of RC beams was established after collecting 452 test results of RC beams, and Pearson correlation analysis was conducted for feature selection to determine the input mechanical parameters and dimensional parameters for machine learning. Meanwhile, the correlation between the inputs and limit values was analyzed using the mutual information method. Regression models of seven machine learning methods were then established to predict the performance level limits of RC beams, and the hyperparameters of the machine learning models were optimized with the TPE optimization algorithm and cross-validation. The generalization ability of the prediction models was evaluated and the accuracy of predicted results by different methods was analyzed. Finally, the predicted seismic performance level limits of RC beams could be used to evaluate the earthquake-induced damage of RC beams by combining them with the seismic behavior of RC beams.

塑性旋转角或挠度通常被用作评估地震引起的破坏和划分钢筋混凝土（RC）梁抗震性能等级的指标。其中，最重要的问题之一是确定钢筋混凝土梁的抗震性能等级限值。不同国家提供了各自特定的方法，通过考虑钢筋混凝土梁的承载能力来确定限值，但这些方法无法用于描述地震引起的结构渗流，尤其是地下结构。因此，本研究采用机器学习方法，并考虑裂缝的发展情况，对 RC 梁的抗震性能等级限值进行了预测。首先，在讨论了不同规范的方法和裂缝发展情况后，介绍了 RC 梁的抗震性能等级限制。然后，在收集了 452 个钢筋混凝土梁的试验结果后，建立了钢筋混凝土梁抗震性能试验数据库，并对特征选择进行了皮尔逊相关分析，以确定机器学习的输入力学参数和尺寸参数。同时，使用互信息方法分析了输入值和极限值之间的相关性。然后建立了七种机器学习方法的回归模型来预测 RC 梁的性能等级限值，并利用 TPE 优化算法和交叉验证对机器学习模型的超参数进行了优化。评估了预测模型的泛化能力，并分析了不同方法预测结果的准确性。最后，结合钢筋混凝土梁的抗震行为，预测出的钢筋混凝土梁抗震性能等级限值可用于评估地震诱发的钢筋混凝土梁破坏。

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引用次数: 0

Laboratory investigation of liquefaction mitigation in sand using zeolite-cement injection 利用沸石-水泥注入缓解砂土液化的实验室研究

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-05 DOI: 10.1016/j.soildyn.2024.109014

The study on liquefaction mitigation using cement-based materials in soils with liquefaction potential is of great interest. As cement production is a costly and environmentally polluting process, replacing part of it with environmentally friendly and cheaper materials such as natural zeolite is very important and attractive. In the present study, to evaluate the improvement of the liquefaction resistance in loose sand using zeolite-cement injection, a series of triaxial tests was performed. Also, the liquefaction potential of injected specimens was investigated based on the results of bender element, unconfined compressive strength and monotonic triaxial tests. The results of the study indicated that the injection of tested sand with zeolite-cement grout is significantly effective in liquefaction mitigation of the sand. Even under very strong earthquakes, liquefaction did not occur in the injected specimens with water to cementitious materials' ratio (W/CM) of 3 and a cement replacement with zeolite (Z) up to 70 %. The optimum amount of zeolite (Z_opt) corresponding to the maximum liquefaction resistance was 30 %. It was shown that, considering the optimization of energy consumption as well as environmental considerations, for earthquakes with a CSR ≤ 0.2, by grout injection with Z₉₀ and W/CM of 5, the used sand liquefaction resistance is more than double. For more severe earthquakes (CSR ≤ 0.3), injection with a grout containing Z₇₀ and W/CM of 7 resulted in no liquefaction. To counteract the liquefaction under very strong earthquakes (CSR_0.5), grout injection with Z₅₀ and W/CM of 5 can be effective.

在具有液化潜力的土壤中使用水泥基材料缓解液化的研究非常有意义。由于水泥生产是一个成本高昂且污染环境的过程，因此用天然沸石等环境友好且成本较低的材料来替代部分水泥生产是非常重要且有吸引力的。在本研究中，为了评估利用沸石-水泥注入改善松散砂土抗液化性能的情况，进行了一系列三轴试验。此外，还根据弯管元件、无侧限抗压强度和单调三轴试验的结果，对注入试样的液化潜力进行了研究。研究结果表明，在试验砂中注入沸石-水泥灌浆料对缓解砂的液化非常有效。即使在非常强烈的地震中，水与胶凝材料比（W/CM）为 3、沸石（Z）水泥替代率高达 70% 的注入试样也不会发生液化。与最大液化阻力相对应的沸石最佳用量（Zopt）为 30%。研究表明，考虑到能源消耗的优化和环境因素，对于 CSR ≤ 0.2 的地震，通过注入 Z90 和 W/CM 为 5 的注浆，所用砂土的抗液化能力提高了一倍以上。对于更严重的地震（CSR ≤ 0.3），注入含 Z70 和 W/CM 为 7 的灌浆料不会导致液化。在极强烈地震（CSR0.5）下，注入含 Z50 和 W/CM 为 5 的灌浆材料可有效抵御液化。

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引用次数: 0

Effect of moving train load on ground movement and tunnel deformation due to stacked shield tunnelling 动车荷载对堆叠式盾构隧道地面移动和隧道变形的影响

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-04 DOI: 10.1016/j.soildyn.2024.108992

Stacked tunnel constructions adjacent to operating metro lines are frequently encountered in dense underground space, leading to undesired settlement and existing tunnel deformation. In this paper, ground movement and tunnel deformation were studied due to stacked shield tunnelling using field monitoring and numerical simulation, particularly the effect of adjacent moving train load on ground and tunnel responses was mainly investigated. Numerical model was implemented based one engineering project of the stacked shield tunnel in Tianjin, China. The results indicate that the ground vertical deformation is influenced by the position of new tunnel and existing tunnel, while the ground horizontal deformation occurs specifically at the top of the new tunnel. The train load contributes to an increase in both vertical and horizontal deformations of the ground and an intensified longitudinal settlement deformation in the existing tunnel. A ground settlement prediction was proposed that considers the stiffness of the existing tunnel and effect of train load. This study provides an in-depth investigation into the deformation of ground and existing tunnel and addressed the non-negligible effect of adjacent train load when evaluating safety of stacked shield tunnelling.

在密集的地下空间中，经常会遇到与运营中的地铁线路相邻的堆载隧道施工，从而导致意外沉降和现有隧道变形。本文利用现场监测和数值模拟研究了叠合盾构隧道施工引起的地面运动和隧道变形，尤其是邻近的动车组荷载对地面和隧道响应的影响。数值模型是基于中国天津的一个堆载盾构隧道工程项目实现的。结果表明，地面垂直变形受新建隧道和既有隧道位置的影响，而地面水平变形主要发生在新建隧道顶部。列车荷载导致地面垂直和水平变形增加，并加剧了既有隧道的纵向沉降变形。考虑到既有隧道的刚度和列车荷载的影响，提出了地面沉降预测方法。这项研究对地面和现有隧道的变形进行了深入调查，并解决了在评估堆叠式盾构隧道安全时邻近列车荷载不可忽略的影响问题。

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引用次数: 0

Experimental and numerical investigation of a novel passive energy dissipation system with viscoelastic damper and angle-reaction controller 带粘弹性阻尼器和角度反应控制器的新型被动消能系统的实验和数值研究

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-04 DOI: 10.1016/j.soildyn.2024.108939

Sharp and significant changes in the relative angle between beam and column during earthquakes often lead to failure of structural joints. This study proposed a novel passive Energy Dissipation system (PEDs) consisting of a viscoelastic damper (VED) and an angle-reaction controller (ARC). The ARC provides mutual support to the joint by establishing temporary supports in reinforced concrete or steel frames to allow for free-angle multilevel control in the case of excessive relative angle. This feature distinguishes the novel PEDs from previous systems as it allows the reaction force of the temporary support to compensate for the loss of joint rotational stiffness. The cyclic loading tests were conducted by constructing fundamental components, and then a mechanical model for the novel PEDs was established. Numerical simulations were performed to analyze parameter variations and to provide a comprehensive methodology for evaluating the seismic performance of the novel PEDs. The results demonstrated that two mechanisms were effectively incorporated into the novel PEDs: vibration energy dissipation and protection against excessive angles. The multistage flag hysteresis curve confirmed the reliability of our theoretical model in representing this novel PEDs. Therefore, supplementing rotational stiffness while achieving energy dissipation can be considered a new approach for enhancing seismic performance in frame structures.

在地震中，梁和柱之间相对角度的急剧和显著变化往往会导致结构连接失效。本研究提出了一种新型被动消能系统（PEDs），由粘弹性阻尼器（VED）和角度反应控制器（ARC）组成。ARC 通过在钢筋混凝土或钢架上建立临时支撑来为连接提供相互支撑，从而在相对角度过大时实现自由角度多级控制。这一特点使新型 PED 有别于以往的系统，因为它允许临时支撑的反作用力补偿关节旋转刚度的损失。通过构建基本组件进行了循环加载试验，然后建立了新型 PED 的机械模型。数值模拟分析了参数变化，为评估新型 PED 的抗震性能提供了全面的方法。结果表明，新型 PED 中有效地融入了两种机制：振动能量消耗和防止角度过大。多级标志滞后曲线证实了我们的理论模型在表示这种新型 PED 方面的可靠性。因此，在实现能量耗散的同时补充旋转刚度可被视为提高框架结构抗震性能的一种新方法。

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引用次数: 0

Seismic performance of Li-Tie type brick masonry infilled wooden frames considering joint damage: Degradation mechanism and hysteretic model 考虑接缝破坏的 Li-Tie 型砖砌体填充木框架的抗震性能：退化机制和滞后模型

IF 4.2 2区工程技术 Q1 ENGINEERING, GEOLOGICAL

Soil Dynamics and Earthquake Engineering

Pub Date : 2024-10-04 DOI: 10.1016/j.soildyn.2024.109008

This paper investigated the influence of the damage to column-foot (C-F) joints and the gaps of mortise-tenon (M-T) joints on the seismic behavior of Li-Tie style timber frames with masonry-infilled wall. Five full-scale Li-Tie type brick masonry-infilled timber frames, two without the joint damage, two with the damage to C-F, and one with the gaps of M-T joints, were cyclically tested. The failure modes, mechanical and deformation mechanisms were revealed. The second-order effect, strength degradation law, and the changing laws of the equivalent viscous damping coefficient and strain of the specimens were analyzed. The results showed that when the maximum inter-layer drift ratio was less than 2.4 %, the second-order effect of Li-Tie type timber structure with the masonry infill can be ignored. The masonry infilled timber frames considering the joint deterioration suffered a large strength degradation degree, and a more significant loss of the peak load and ductility. The equivalent viscous damping coefficient of the masonry infilled timber frame considering C-F damage increased by up to 24.67 %, while that of the one including the gaps of M-T joint decreased by 6.67 %. The C-F damage led to an increase in the strain at the beam end, the damage to M-T joint resulted in an decrease in the strain at the beam end. However, the damage to C-F and the gaps in M-T joint had little influence on the strain distribution in the C-F area. Based on the hysteretic, stiffness and strength degradation characteristics, and tests results of the specimens, the new tri-linear hysteretic models of Li-Tie type brick masonry infilled wooden frames with and without the joint damage were established and verified. Good agreement between the model predictions and test results was observed.

本文研究了柱脚（C-F）接缝损坏和榫卯（M-T）接缝间隙对砌体填充墙 Li-Tie 型木结构抗震性能的影响。对五种全尺寸的锂铁式砖砌体填充木框架进行了周期性试验，其中两种框架的接缝没有损坏，两种框架的 C-F 接缝有损坏，一种框架的 M-T 接缝有间隙。试验揭示了破坏模式、力学和变形机理。分析了试样的二阶效应、强度退化规律以及等效粘滞阻尼系数和应变的变化规律。结果表明，当最大层间漂移比小于 2.4 % 时，带砌体填充物的 Li-Tie 型木结构的二阶效应可以忽略。考虑了接缝劣化的砌体填充木结构强度退化程度较大，峰值荷载和延性损失较明显。考虑 C-F 损伤的砌体填充木框架的等效粘性阻尼系数增加了 24.67%，而包括 M-T 接缝间隙的砌体填充木框架的等效粘性阻尼系数则降低了 6.67%。C-F 破坏导致梁端应变增加，M-T 连接破坏导致梁端应变减少。然而，C-F 的损坏和 M-T 接头的间隙对 C-F 区域的应变分布影响不大。根据试件的滞回、刚度和强度退化特征以及试验结果，建立并验证了有和无接缝损坏的锂铁砌体砖填充木框架的新三线性滞回模型。结果表明，模型预测与试验结果之间具有良好的一致性。

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引用次数: 0