Soil Dynamics and Earthquake Engineering最新文献

{"title":"Simplified site response analysis for regional seismic risk assessments","authors":"James Bantis ,&nbsp;Eduardo Miranda ,&nbsp;Pablo Heresi","doi":"10.1016/j.soildyn.2024.109022","DOIUrl":"10.1016/j.soildyn.2024.109022","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"188 ","pages":"Article 109022"},"PeriodicalIF":4.2,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442234","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":"Long-term effect of soil settlement on lateral dynamic responses of end-bearing friction pile","authors":"Chunyu Song ,&nbsp;Zhaowei Ding ,&nbsp;Lei Huang ,&nbsp;Lingsen Zhao","doi":"10.1016/j.soildyn.2024.109041","DOIUrl":"10.1016/j.soildyn.2024.109041","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"188 ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442235","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":"A PSHA for Mexico City based solely in Fourier-based GMM of the response spectra","authors":"Mario Ordaz ,&nbsp;Danny Arroyo ,&nbsp;Shri K. Singh ,&nbsp;Mario A. Salgado-Gálvez","doi":"10.1016/j.soildyn.2024.109025","DOIUrl":"10.1016/j.soildyn.2024.109025","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"187 ","pages":"Article 109025"},"PeriodicalIF":4.2,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433669","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":"Dynamic analysis for horizontal vibration of piles in layered Pasternak soils considering secondary ground waves","authors":"Yu Xin ,&nbsp;Chunyi Cui ,&nbsp;Hailong Liu ,&nbsp;Benlong Wang ,&nbsp;Chengshun Xu ,&nbsp;Lina Xu ,&nbsp;Guoyang Fu","doi":"10.1016/j.soildyn.2024.109026","DOIUrl":"10.1016/j.soildyn.2024.109026","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"187 ","pages":"Article 109026"},"PeriodicalIF":4.2,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433670","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":"Mitigation of numerical dispersion in seismic data in spectral domain with neural networks","authors":"Kirill Gadylshin,&nbsp;Elena Gondyul,&nbsp;Vadim Lisitsa,&nbsp;Ksenia Gadylshina,&nbsp;Dmitry Vishnevsky","doi":"10.1016/j.soildyn.2024.109028","DOIUrl":"10.1016/j.soildyn.2024.109028","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"187 ","pages":"Article 109028"},"PeriodicalIF":4.2,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433668","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 retrofitting of GFRP-reinforced concrete columns using precast UHPC plates","authors":"Cheng Wu ,&nbsp;Gao Ma ,&nbsp;Deju Zhu ,&nbsp;Hongya Qu ,&nbsp;Haiyang Zhuang","doi":"10.1016/j.soildyn.2024.109024","DOIUrl":"10.1016/j.soildyn.2024.109024","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"187 ","pages":"Article 109024"},"PeriodicalIF":4.2,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433667","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":"Regional study of site effects on the high-frequency spectral-decay parameter","authors":"Zhengru Tao ,&nbsp;Pei Xiao ,&nbsp;Jiayao Li ,&nbsp;Yuwei Huang ,&nbsp;Zhiguo Tao","doi":"10.1016/j.soildyn.2024.109030","DOIUrl":"10.1016/j.soildyn.2024.109030","url":null,"abstract":"<div><div>The high-frequency spectral-decay parameter <em>κ</em> has been used in the field of engineering seismology for several decades. The zero-distance <em>κ</em> value (<em>κ</em>₀) 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 <em>κ</em>₀, 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 <em>κ</em>₀ on two horizontal components and the median value of the rotated <em>κ</em>₀ at surface and borehole stations. The same process was applied to <em>Δκ</em>₀, the difference between surface station <em>κ</em>₀ and borehole station <em>κ</em>₀, 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 <em>κ</em> is investigated. In the same area, strong ground motion records with peak ground acceleration &gt;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 <em>κ</em> at the 50 surface stations were assessed.</div></div>","PeriodicalId":49502,"journal":{"name":"Soil Dynamics and Earthquake Engineering","volume":"187 ","pages":"Article 109030"},"PeriodicalIF":4.2,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433666","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":"The role of underground archaeological remains on the seismic response of a historic tower","authors":"A. Ambrosino,&nbsp;S. Sica","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":"187 ","pages":"Article 109017"},"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":"Yu-Liang Lin ,&nbsp;Li Lu ,&nbsp;Xiao-Bin Chen ,&nbsp;Yuan Xue ,&nbsp;Zhi-meng Wang","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":"187 ","pages":"Article 109003"},"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":"G. Pianese ,&nbsp;N. Van Engelen ,&nbsp;H. Toopchi-Nezhad ,&nbsp;G. Milani","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":"187 ","pages":"Article 109016"},"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}