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1دورية أكاديمية
المؤلفون: Taiebat, Mahdi, Jeremic, Boris, Dafalias, Yannis, Kaynia, Amir, Cheng, Zhao
المصدر: Soil Dynamics and Earthquake Engineering. 30(4)
وصف الملف: application/pdf
الوصول الحر: https://escholarship.org/uc/item/3nm1327rTest
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المؤلفون: Zuada Coelho, Bruno, Nuttall, J., Noordam, A., Dijkstra, Jelke, 1980
المصدر: Soil Dynamics and Earthquake Engineering. 169
مصطلحات موضوعية: Soil variability, Finite element, Wave propagation, Random fields
الوصف: Soil is by nature a variable, non-homogeneous material, which has implications for engineering problems involving wave propagation. This paper investigates the impact of the spatial heterogeneity of the stiffness of the soil on the three-dimensional wave propagation. A dynamic Random Finite Element Model is presented in which the soil variability is modelled by means of random fields, applied to the Young's modulus of the soil, following a Monte-Carlo approach. The results show the importance of accounting for soil variability when making predictions on the maximum vibration level. Deterministic analysis is demonstrated to be insufficient when quantifying the maximum vibration level, because no information on the expected variability of the maximum vibration level is obtained. Furthermore, the scale of fluctuation and anisotropy of the random field strongly impact the estimation of the maximum vibration level, and the time of occurrence.
الوصول الحر: https://research.chalmers.se/publication/534946Test
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3دورية أكاديمية
المصدر: Soil Dynamics and Earthquake Engineering
مصطلحات موضوعية: Structure soil structure interaction (SSSI), Integral transform method (ITM), Finite element method (FEM), Substructure technique, Elastic wave propagation, Flexible foundation
الوصف: The dynamic response of rigid and flexible three-dimensional (3D) foundations of arbitrary shape, placed on a homogeneous or layered halfspace, which may contain a finite, longitudinally invariant structure or inhomogeneity, is determined numerically. A 2.5D coupled Integral Transform Method (ITM) - Finite Element Method (FEM) approach is used to compute the dynamic compliance at the surface of the stratified soil with inclusion, whereas 3D ITM fundamental solutions are applied in case of a homogeneous or layered subgrade. The foundation is modelled by 3D finite elements in both cases and coupled to the underlying ground by enforcing the compatibility conditions at the interface. Compliance functions at the soil foundation interface are presented and compared with existing solutions for verification as well as displacement distributions within the underlying ground are illustrated. The influence of the foundation stiffness on the total response as well as on the frequency dependent power transmission into the soil due to different load types is studied. Finally, the method is applied to evaluate the influence of a tunnel and a stiff cylindrical inclusion on the dynamic response of the foundation, thereby demonstrating the importance of taking into account the Structure-Soil-Structure-Interaction (SSSI).
الإتاحة: https://doi.org/10.1016/j.soildyn.2021.107007Test
https://grafar.grf.bg.ac.rs/handle/123456789/2452Test -
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المؤلفون: Hongjing Li, Michael J. O'Rourke
المصدر: Soil Dynamics and Earthquake Engineering. 116:612-619
مصطلحات موضوعية: Total internal reflection, Wave propagation, Wave velocity, 0211 other engineering and technologies, Soil Science, 020101 civil engineering, 02 engineering and technology, Amplification factor, Geotechnical Engineering and Engineering Geology, Seismic wave, Physics::Geophysics, 0201 civil engineering, Shear (geology), Inclination angle, Seismic wave propagation, Seismology, Geology, 021101 geological & geomatics engineering, Civil and Structural Engineering
الوصف: It is recognized that seismic damages to segmented buried pipelines depend in part upon transient ground strain due to seismic wave propagation. Such wave propagation damage seems to be larger at sites with variable subsurface conditions, because of drastic changes in seismic wave characteristics as they propagates in heterogeneous rock and soil layers. This paper intends to investigate the amplification of horizontal ground strains in a valley subjected to vertically incident SH waves. A 2D model with an inclined soil-rock interface is established to simulate conditions of the valley subject to seismic wave propagation. A procedure for evaluating the ground strain amplification is developed by consideration of travel path effects. Three amplification/de-amplification mechanisms are specifically considered, the ground velocity amplification, ground strain amplification due to the change in the propagation direction, and de-amplification due to a lack of total reflection at the soil-rock interface. The analysis results show that the maximum amplification factor is mainly affected by the interface inclination angle and shear wave velocity ratio between the valley soil and the base rock. For a given number of wave cycles, the amplification factor grows with the increment of the inclination angle and declines with the growth of shear wave velocity ratio. The de-amplification at inclined interface is likely to nullify the amplification generated by travel path effects.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::1ad2c0972c27f756e16e26592fb2cf07Test
https://doi.org/10.1016/j.soildyn.2018.10.018Test -
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المؤلفون: Qiang Xu, Jianyun Chen, Dapeng Qiu
المصدر: Soil Dynamics and Earthquake Engineering. 117:216-220
مصطلحات موضوعية: Ground motion, Scale (ratio), Horizontal and vertical, Wave propagation, Frame (networking), 0211 other engineering and technologies, Soil Science, Boundary (topology), Oblique case, 020101 civil engineering, 02 engineering and technology, Geotechnical Engineering and Engineering Geology, Seismic wave, Physics::Geophysics, 0201 civil engineering, Geology, Seismology, 021101 geological & geomatics engineering, Civil and Structural Engineering
الوصف: This paper mainly focuses on distinctive dynamic responses of the underground large scale frame structure (ULSFS) under obliquely asynchronous seismic inputs of the near-fault ground motion. To achieve the arbitrarily oblique input of seismic waves, the ground motions are transformed into equivalent forces adding on the 3-D viscous-spring artificial boundary nodes based on the theory of wave propagation. The ULSFS with great scales along two horizontal directions are proposed according to a well-designed underground market under construction. The dynamic responses of the ULSFS under different oblique incident angles of seismic waves are compared. The failure mechanisms of the ULSFS are explored by the tensile damage of floor slabs and walls, and stresses and strains of frame columns. The results demonstrate that dynamic responses of the ULSFS with two horizontal great scales would be sensitive to oblique incident angles of the seismic input; and the ULSFS is more likely to be compression-shear failure under the combination of the asynchronous horizontal and vertical seismic waves.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::62238a7e5571187c712e6c0e3b0fae89Test
https://doi.org/10.1016/j.soildyn.2018.11.032Test -
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المؤلفون: Domniki Asimaki, Joseph Wartman, Jacob Dafni, Seokho Jeong
المصدر: Soil Dynamics and Earthquake Engineering. 116:654-667
مصطلحات موضوعية: Centrifuge, Wave propagation, 0211 other engineering and technologies, Soil Science, 020101 civil engineering, Laminar flow, 02 engineering and technology, Mechanics, Geotechnical Engineering and Engineering Geology, Finite element method, 0201 civil engineering, Stratigraphy, Spatial variability, Seismic risk, Material properties, Geology, 021101 geological & geomatics engineering, Civil and Structural Engineering
الوصف: Topographic effects, the modification of seismic shaking by irregular topographies compared to flat ground, have been extensively studied. Very few studies, however, have investigated the effects of the stratigraphy and nonlinear response of the underlying geology on topographic amplification. Furthermore, most experimental studies have been performed in the field, where it is often difficult to establish an ideal flat-ground reference station, as well as to characterize the soil properties and their spatial variability in sufficient detail. Dafni [1] recently tested the seismic response of step-like slopes in a series of centrifuge experiments, where the incident motion, reference station and material properties were characterized in detail. In this study, we investigated the influence of the container boundary on topographic effects observed in the centrifuge experiments by performing numerical simulations with and without the container boundary. Our analysis suggested that the rigid-body rocking motion of the centrifuge container likely increased the experimental topographic spectral ratios, contributing to the discrepancy between the simulated and observed spectral ratios. We also found that although the laminar box lateral boundaries caused spurious reflections, they didn't qualitatively affect the ground surface amplification pattern compared to numerical predictions of the same configuration without boundaries. At the same time, and most importantly, however, we found that the baseplate –by trapping waves scattered and diffracted by the slope– amplified the ground motion at the crest up to one order of magnitude compared to numerical predictions of the response in absence of the baseplate. Our results show that topographic effects can be significantly affected by the underlying soil stratigraphy, and allude to the potentially significant role of this phenomenon in elevating seismic risk in regions with strong topographic relief. The findings of this study also suggest that future studies will benefit from clear understanding and careful considerations of capabilities and limitations of different investigation methods and that the numerical modeling and the lab testing (or the field testing) methods should complement each other.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::e0c49b4e2b73a799fe6b2bb57ad3f75cTest
https://doi.org/10.1016/j.soildyn.2018.10.028Test -
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المؤلفون: Xiuli Du, Mi Zhao, Shurui Wang, Zilan Zhong, Liyun Li
المصدر: Soil Dynamics and Earthquake Engineering. 115:776-786
مصطلحات موضوعية: 021110 strategic, defence & security studies, business.industry, Cured-in-place pipe, 0211 other engineering and technologies, Soil Science, 020101 civil engineering, 02 engineering and technology, Structural engineering, engineering.material, Dissipation, Geotechnical Engineering and Engineering Geology, Seismic wave, 0201 civil engineering, Pipeline transport, Ductile iron, engineering, Seismic wave propagation, business, Geology, Civil and Structural Engineering
الوصف: The cured in place pipe (CIPP) liner technology is to install flexible polymeric liners with thermosetting resin inside existing pipelines. Compared with traditional methods of pipeline retrofits, CIPP provides an economic and environmentally friendly alternative for pipeline rehabilitation. However, the lack of proper constitutive models of the push-on joints and the CIPP-liner reinforced joints remains a critical deficiency in current numerical simulations of buried segmental pipelines. This paper presents new constitutive models of ductile iron (DI) push-on joints, before and after reinforced with one type of the CIPP liners, commonly used in pipeline retrofits. The proposed models were calibrated from the full-scale quasi-static tests performed on water-pressurized DI pipelines with push-on joints. These new joint models, considering strength degradation and energy dissipation of the joint, well characterizes the longitudinal behavior of the push-on joint and the liner-strengthened joints under repetitive axial loading, which primarily represents the expansion and contraction effects of the joints due to thermal effects or seismic waves traveling along the buried pipelines. Moreover, this paper also provides a rational procedure for evaluating the seismic performance of buried pipeline with different push-on joints. The proposed numerical procedure could be generally applied to quantify the seismic performance of buried straight pipelines incorporating the proposed joint models under seismic wave propagation. Numerical results indicate that the CIPP liner can significantly improve the seismic performance of the push-on joints subjected earthquake induced transient ground deformations.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::77cf201c5d5701dd01ad8fb29a65bd78Test
https://doi.org/10.1016/j.soildyn.2018.09.031Test -
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المؤلفون: Yaqiang Liu, Guohuan Liu, Haitao Yu, Jijian Lian
المصدر: Soil Dynamics and Earthquake Engineering. 115:104-118
مصطلحات موضوعية: 021110 strategic, defence & security studies, Computer simulation, Wave propagation, 0211 other engineering and technologies, Soil Science, Spectral density, 020101 civil engineering, Soil science, 02 engineering and technology, Half-space, Geotechnical Engineering and Engineering Geology, Physics::Geophysics, 0201 civil engineering, Seismic analysis, Amplitude, Reflection (physics), Response spectrum, Geology, Civil and Structural Engineering
الوصف: Simulation of multi-support (i.e. spatially variable) seismic underground motions in sea areas plays a significant role in the seismic analysis of cross-sea structures such as cross-sea bridges or subsea tunnels. However, existing approaches for predicting multi-support seismic motions mainly focus on the dry site soils without overlying surface water. This paper proposes an approach for predicting multi-support seismic underground motions in layered saturated half space under surface water, subjected to oblique incident P waves. The transfer function in saturated soil under surface water, as the theoretical basis of the subsequent numerical simulation, is first derived based on wave propagation theory and the calculated reflection coefficients of P wave–induced P1, P2, SV waves in saturated soils. The derived transfer function is further employed to deduce and obtain the underground (sub-seabed) power spectral density function and response spectrum function. The two obtained functions, combined with the additional cross-coherence function, are subsequently employed to construct the cross power spectral density matrix and thus to simulate multi-support seismic underground motions. The solutions are validated against the target power spectral density, target response spectrum and target cross-coherence functions. A parametric analysis is presented where the effects of the soil thickness, the incident angle and the overlying water depth are investigated. Results show that the soil thickness, incident angle and overlying water depth have significant influences on the amplitude of transfer functions, which further affect the ratios between seismic ground and underground motions.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::df97937c607a3e44fa3080cd418199a1Test
https://doi.org/10.1016/j.soildyn.2018.08.009Test -
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المؤلفون: Amir M. Kaynia, Joonsang Park
المصدر: Soil Dynamics and Earthquake Engineering. 115:169-182
مصطلحات موضوعية: Physics, Wave propagation, Mathematical analysis, Isotropy, Soil Science, Stiffness, Boundary (topology), 020101 civil engineering, Context (language use), 02 engineering and technology, Geotechnical Engineering and Engineering Geology, 0201 civil engineering, Discontinuity (linguistics), 020303 mechanical engineering & transports, Perfectly matched layer, 0203 mechanical engineering, medicine, medicine.symptom, Civil and Structural Engineering, Stiffness matrix
الوصف: In this study, we introduce and discuss features and improvements of the well-established stiffness matrix method that is used in simulation of wave propagation in layered media. More specifically, we present stiffness matrices for an acoustic layer and a vertically transverse isotropic (VTI) viscoelastic soil layer. Combining these stiffness matrices enables a straightforward technique for modeling of acousto-elastic wave propagation in layered infinite media. In addition, we propose a technique to simulate discontinuity seismic sources, which was not used earlier in the context of the stiffness matrix method. Finally, we propose a framework to derive a key parameter of the absorbing boundary domain technique Perfectly Matched Layer (PML). Numerical examples are presented in order to help understanding the features and improvements discussed in the study from the fields of geophysics and soil dynamics. It is believed that the features and improvements discussed herein will make the application of the stiffness matrix method even wider and more flexible.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::1f292d6c96f0f42acebfc088d3158be1Test
https://doi.org/10.1016/j.soildyn.2018.06.030Test -
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المؤلفون: Domniki Asimaki, Kami Mohammadi
المصدر: Soil Dynamics and Earthquake Engineering. 114:424-437
مصطلحات موضوعية: Earthquake engineering, Wave propagation, Linear elasticity, 0211 other engineering and technologies, Elevation, Soil Science, Context (language use), 02 engineering and technology, Geophysics, 010502 geochemistry & geophysics, Geotechnical Engineering and Engineering Geology, 01 natural sciences, Seismic wave, Physics::Geophysics, Amplitude, Stratigraphy, Geology, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, Civil and Structural Engineering
الوصف: Documented observations from strong seismic events have repeatedly shown that the ground surface topography significantly affects the characteristics of seismic waves (amplitude, frequency and duration) travelling from the deeper layers of the crust compared to what the ground motion would have been on the surface of a flat homogeneous linear elastic half-space. Although numerous theoretical studies have qualitatively corroborated these observations, they systematically underestimate the absolute level of topographic amplification up to an order of magnitude or more in some cases. In this paper, we try to bridge the quantitative gap between previous theoretical studies and observations by systematically studying the role of geometry, stratigraphy, and ground motion characteristics through a series of elaborate numerical analyses. We show a collection of examples that highlight the effects of topography on seismic ground shaking, and we point out what these results suggest in the context of the current state of earthquake engineering practice. Examples range from semi-analytical solutions of wave propagation in infinite wedges to three-dimensional numerical simulations of topography effects using digital elevation map-generated models and layered geologic features. We conclude by demonstrating that topography effects vary strongly with the stratigraphy and material properties of the underlying geologic materials, and thus it cannot be accurately predicted by studying the effects of ground surface geometry alone.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::30d156f6edfd2208556d7e904248060dTest
https://doi.org/10.1016/j.soildyn.2018.07.020Test
