Soil Dynamics and Earthquake Engineering最新文献

{"title":"The role of underground archaeological remains on the seismic response of a historic tower","authors":"","doi":"10.1016/j.soildyn.2024.109017","DOIUrl":"10.1016/j.soildyn.2024.109017","url":null,"abstract":"<div><div>The Italian territory features plenty of historic masonry buildings, many of which have undergone reconstruction, often atop ancient ruins. The presence of archaeological remains in the shallow layers of the ground is always disregarded in the seismic assessment of masonry buildings. To address this gap, the paper delves into the influence of underground masonry ruins on the seismic response of a bell tower built above a historic soil deposit. A comprehensive 3D finite-element model encompassing the tower, foundation, soil, and underground remains was developed. A parametric analysis was conducted, involving modifications to the geometry, mechanical properties, and location of the buried ruins. From the parametric study it emerged that the buried walls could alter the seismic signal at the base of the structure. The most critical scenario occurs when the buried archaeological ruins have a grid spacing comparable to the characteristic size of the foundation, especially in soft soils. Analysis of displacements, accelerations, and spectral accelerations at different elevations along the tower height revealed that the presence of archaeological ruins could modify the seismic response of the structure built above them.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shaking table experiment on seismic response of a three-stage slope supported by anchoring lattice beam","authors":"","doi":"10.1016/j.soildyn.2024.109003","DOIUrl":"10.1016/j.soildyn.2024.109003","url":null,"abstract":"<div><div>Multi-stage anchoring lattice beam is widely used to support high slope in high earthquake intensity area, while the seismic behavior and interaction are not very clear. The previous studies mainly focused on a single-stage slope, while the analysis of multi-stage effect on the seismic response of anchoring lattice beam is lacking. Subsequently, a shaking table experiment was carried out to investigate the dynamic characteristics and seismic responses of a three-stage slope supported by an anchoring lattice beam. The displacement mode and the residual displacement are observed by Digital Image Correlation (DIC) technology. Kobe and Landers ground motions were input in shaking table test with an increasing order of shaking intensity. The original Kobe motion was applied at the last sequence to investigate the effect of frequency characteristic of ground motion. The results show that the acceleration response increases nonlinearly along the height of three-stage slope, and a reduction of acceleration response is observed at platform. The energy within a frequency band close to natural frequency of three-stage slope is especially amplified. The anchor takes more responsibility to resist the seismic loading, and decreases the earth pressure behind lattice beam. By setting multiple stages, the acceleration amplification and seismic earth pressure are reduced effectively. The intensity and the frequency characteristic of seismic motion affect the axial strain of anchor. The potential local failure and the frequency characteristic of seismic motion are suggested to be considered in seismic design.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420010","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}

{"title":"An experimental and numerical insight into the unbonded and partially bonded high-damping fiber-reinforced elastomeric isolators","authors":"","doi":"10.1016/j.soildyn.2024.109016","DOIUrl":"10.1016/j.soildyn.2024.109016","url":null,"abstract":"<div><div>Elastomeric isolators are commonly used for seismic isolation. Typically, they are composed of alternating rubber pads and steel laminas. The composite action provides horizontal flexibility through the rubber and vertical and rotational stiffness through the steel. However, due to costs, they are mainly limited to use in strategic, nonresidential structures, especially in developing countries. A new elastomeric device, the fiber-reinforced elastomeric isolator (FREI), has been developed using fiber layers instead of steel laminas, reducing costs. FREIs offer bonded (traditional), unbonded, and partially bonded applications. In the unbonded setup, FREIs are placed between structures and foundations without any bonding or fastening. The shear load is transferred through the friction generated between the isolator and the structure surfaces, improving the seismic performances and the damping ability compared to the same device in a bonded condition. However, they can't resist vertical tension. The partially bonded approach addresses this by partially attaching the contact surfaces of the device to connection steel plates, retaining the advantages of both bonded and unbonded methods. Central to the efficacy of these isolators is the rubber material itself. Natural rubber (NR) is the most used, but artificial rubber is promising for the fabrication of isolators because NR has a poor damping performance, it is vulnerable to quick aging, and its industrial production is of concern. Factors such as escalating demand, price fluctuations, high labor costs, trade policies, and a ban on deforestation have made NR production unreliable.</div><div>This paper presents an in-depth investigation of circular high-damping FREIs in both partially bonded and unbonded applications. The study employs a combined numerical and experimental approach. It provides a detailed explanation of the design process, numerical modeling, and experimental characterization for both the rubber material and the seismic devices, highlighting the advantages of design optimization based on preliminary numerical results. This methodology can serve as a valuable example, offering significant help to manufacturers and engineers. Additionally, a novel simplified analytical model is introduced for the employment of unbonded and partially bonded FREIs in structural applications, based on the fitting of cyclic shear tests used for the characterization of the dynamic properties of the elastomeric devices.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Convolutional neural network-based seismic response prediction method using spectral acceleration of earthquakes and conditional vector of structural property","authors":"","doi":"10.1016/j.soildyn.2024.109021","DOIUrl":"10.1016/j.soildyn.2024.109021","url":null,"abstract":"<div><div>This study proposes a method for predicting the seismic response of structures using seismic information and structural properties. In the proposed method, the relationship between seismic and structural characteristics and seismic responses was investigated using a convolutional neural network (CNN) to predict the seismic response. Spectral acceleration (Sa) calculated from the seismic wave was selected as seismic information used in CNN-based seismic response prediction techniques. The study introduced seismic information and structural properties, which correspond to the parameters to express the structure's unique characteristics or nonlinear hysteretic behaviors that determine the response characteristics of the structure subjected to seismic waves. Meanwhile, Sa and structural properties were utilized to constitute the input map of CNN and predict the maximum inter-story drift ratio that corresponds to the output of CNN. As data corresponding to the period range of interest rather than a scalar value for a specific period, Sa is rearranged in matrix form to constitute the input map of CNN. Structural properties are also placed in the input map of CNN as scalar values are converted into conditional vectors. To confirm the validity of the proposed method, multiple CNN-based models with changes in the information of the input map are presented, and their prediction performances are compared. Furthermore, CNN-based models that additionally consider seismic intensity measures are presented, and their influences on seismic response prediction performance are analyzed. In addition, a vast number of linear and nonlinear structures were generated, and seismic responses extracted via seismic analysis of multiple earthquakes were used to create datasets for training the presented models. The prediction performance of the presented models trained using the datasets was compared. The validity of the simultaneous use of structural properties with Sa, the introduction of conditional vectors, the additional use of seismic intensity measures, and their contributions to improving prediction performance were also examined.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142419971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"AI-driven predictions of the dynamic properties of fine-grained soils in South Italy based on laboratory testing","authors":"","doi":"10.1016/j.soildyn.2024.109009","DOIUrl":"10.1016/j.soildyn.2024.109009","url":null,"abstract":"<div><div>This study presents the use of Artificial Intelligence (AI) to predict the dynamic behaviour of fine-grained soils of South Italy based on a detailed laboratory investigation. The investigation consists of Resonant Column (RC), Cyclic Torsional Shear (CTS), and Cyclic Triaxial (CTx) tests performed on 25 specimens of fine-grained soils retrieved from 11 sites in Sicily (South Italy). To develop accurate predictive models of soil dynamic properties, essential for site response analyses and dynamic soil-structure interaction, various regression techniques were applied. These techniques range from Multiple Linear Regression (MLR) to more complex AI methods, specifically Machine Learning (ML) and Deep Learning (DL) based on FeedForward Neural networks (FFN). Three predictive models were developed to derive strain-dependent shear modulus (<em>G</em>), damping ratio (<em>D</em>), and normalized shear modulus (<em>G</em>/<em>G</em>_<em>0</em>), using four inputs: shear strain (<em>γ)</em>, plasticity index (<em>PI)</em>, confining pressure (<em>p’</em>_<em>0</em>), and the Over Consolidation Ratio (OCR). To determine the optimal FFN topology, 1350 networks were developed by varying hidden layers (1–3), hidden neurons (1–50 per layer), and activation functions (ReLU, sigmoid and hyperbolic tangent). Hybrid FFN optimised through Genetic Algorithm and Particle Swarm Optimization techniques were also investigated. Single-hidden layer networks with fewer than 15 neurons provided acceptable predictions (<em>R</em>^<em>2</em>_{<em>test</em>} of 0.97 for <em>G</em>-<em>γ</em>, 0.93 for <em>G</em>/<em>G</em>_<em>0</em>-<em>γ</em>, and 0.85 for <em>D</em>-<em>γ</em> models). Multiple-hidden layer networks yielded higher accuracy for <em>G</em> and <em>D</em> models but are more complex for practical use. The FFN models outperformed MLR and other established empirical formulations, highlighting the site-specificity of the modelling parameters of the latter.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An optimization suggestion for site classification scheme in Chinese seismic code based on clustering analysis of site amplification","authors":"","doi":"10.1016/j.soildyn.2024.109018","DOIUrl":"10.1016/j.soildyn.2024.109018","url":null,"abstract":"<div><div>There has been extensive discussion as to whether the scope of site classification II is too broad in current Chinese seismic code. To address this issue, this study aims to optimize the site classification scheme for Chinese seismic code using clustering analysis of site amplification. Firstly, we estimate the empirical site amplification factors of KiK-net stations by the residual analysis method, and classify them by the site classification scheme of Chinese seismic code. Next, we perform <em>k</em>-means clustering analysis on the stations of site class II, considering site amplification factors, equivalent shear wave velocities and thicknesses of sedimentary layers as explanatory variables, and obtain two clusters with distinct site amplification effects. Finally, we use correlation analysis and Receiver Operating Characteristic (ROC) curve to guide the optimization of site classification scheme, and suggest dividing site class II into two subclasses, II_a and II_b, by a threshold of 15m for the thickness of sedimentary layer. The proposed optimized classification scheme would be beneficial for improving the seismic design code and could be further applied to the development of ground motion models and seismic hazard analysis.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420081","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}

{"title":"Parameter-normalized probabilistic seismic demand model considering the structural design strength for structural response assessment","authors":"","doi":"10.1016/j.soildyn.2024.109023","DOIUrl":"10.1016/j.soildyn.2024.109023","url":null,"abstract":"<div><div>The Probabilistic Seismic Demand Model (PSDM) is a crucial component of the performance-based seismic design framework when establishing the relationship between the ground motion intensity measure (IM) and the engineering demand parameter (EDP). The definitions of IMs and EDPs introduce varying degrees of uncertainty into the PSDM and notes different fragility or hazard analysis results. In accordance with the elastic limit state of the structural seismic response, this study normalizes two key parameters, the IM and EDP, within the PSDM. Normalized EDP (<em>EDP</em>^N) is the ratio of the structural response to the elastic limit state of the structure, as defined by the onset of the strength yielding of the main structural element. Similarly, the IM (<em>IM</em>^N) is normalized based on corresponding ground motions (scaled) that cause the structure to offer an elastic limit state response. This means that structural design strength is considered in <em>IM</em>^N following the construction of a parameter-normalized PSDM. The study examined two typical isolated bridges presented their hazard curves with <em>IM</em>^N. The results show that <em>IM</em>^N can unify the efficiency and sufficiency of different IMs and reduce uncertainty in the PSDM. The assessment error of the structural elastic limit state for its design strength had little effect on the parameter-normalized PSDM, so the model is robust. Additionally, the <em>IM</em>^N outperformed traditional IMs for efficiency and sufficiency in most instances.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420089","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}

{"title":"Seismic behavior of shallow buried water reservoirs via large scale three-dimensional numerical models","authors":"","doi":"10.1016/j.soildyn.2024.109005","DOIUrl":"10.1016/j.soildyn.2024.109005","url":null,"abstract":"<div><div>As buried water reservoirs are increasingly being utilized to store and deliver water, they are now regarded as critical infrastructures that must continue to operate in the event of an earthquake. This paper presents the results of a large-scale numerical parametric study that was carried out to advance our understanding of the seismic fluid-structure-soil interaction (FSSI) response of buried water reservoirs. Advanced nonlinear three-dimensional (3D) FSSI numerical models of reservoirs were employed while considering reservoir size, embedment depth, soil profile, and ground motion variability. The study showed that, unlike other conventional underground structures, the peak ground acceleration (PGA) has the strongest correlation to the reservoir seismic response. Increasing the embedment depth or reservoir size was found to generally increase the demands on the structural elements while reducing the base and backfill slippage. Softer sites were found to cause an increase in the roof racking and including the vertical component of the motion increased the water dynamic pressures. Among the columns, the ones closest to the center were found to experience the highest demands and the ones at the corner the lowest. In fact, in some extreme cases, a total collapse of the reservoir was initiated by column failure due to the lack of structural redundancy. The roof in-plane shear stresses were observed to accumulate near the walls, indicating a diaphragm behavior. The reservoir's unique seismic response compared to other underground structures makes generalizing the commonly used simplified design procedures inapplicable. Instead, 3D FSSI numerical models were demonstrated to be a reliable tool for the seismic design of buried reservoirs.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420088","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}

{"title":"Axial kinematic response of an end-bearing pile subjected to seismic P-wave excitation in a double-layered soil","authors":"","doi":"10.1016/j.soildyn.2024.109012","DOIUrl":"10.1016/j.soildyn.2024.109012","url":null,"abstract":"<div><div>This paper presents an analytical solution for the axial kinematic response of an end-bearing pile under seismic P-wave excitation in a double-layered soil. The motions of the pile and adjacent soil layers are determined using the derived series solution. The seismic wave scattering effect caused by the combined action of the soil layers and pile foundations is accounted for. To validate the accuracy of the derived solution, the kinematic responses obtained from the proposed analytical solution are compared with the results from an existing solution for a pile in a single soil layer. The validated solution is then utilized to conduct a parametric study to investigate the impacts of the modulus and thickness ratios between the two soil layers on response characteristics. These characteristics include the kinematic response factor, amplification factor, frictional force exerted on the pile body, pile displacement with depth, and motion of soil around the pile.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420077","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}

{"title":"Seismic resilience evaluation of confined masonry school buildings retrofitted by shotcrete method","authors":"","doi":"10.1016/j.soildyn.2024.108980","DOIUrl":"10.1016/j.soildyn.2024.108980","url":null,"abstract":"<div><div>This study addresses the urgent need for retrofitting masonry schools in Iran, where over 89 % of schools are constructed using masonry (107000 Schools consisted of 563000 classrooms). Focusing on seismic performance evaluation, this research is of paramount importance as the current state of these schools poses a significant risk to the safety of millions of students. Without proper evaluation, the consequences could be catastrophic. To illustrate the significance of this study, a confined masonry school in Tehran was selected as a representative case study. The seismic resilience index was calculated, considering two hazard levels (2 % and 10 %) over a 50-year period, with and without near-fault pulse-type ground motions. Furthermore, a comparative analysis was conducted by modeling the retrofitted structure, which involved the application of shotcrete on walls, to assess the benefits of retrofitting. The seismic resilience index, derived from analytical functions that account for probable hazards and the recovery process, serves as a comprehensive measure of the structure's vulnerability. Through this evaluation, valuable insights into the retrofitting and rehabilitation of confined masonry schools can be gained. The results obtained from this research will aid in informed decision-making regarding the mitigation of seismic risks in similar structures. In conclusion, this paper indicates applying shotcrete to masonry walls can be substantially efficient as the resilience index and functionality of the building increases by a significant margin. Furthermore, the building damage was halved after the retrofitting operation and fragility curves admit it by showing better performance in higher drift ratios.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420079","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}