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Journal articles on the topic 'Impedance of foundation'

Author: Grafiati

Published: 4 June 2021

Last updated: 1 February 2022

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1

Crouse, C. B., George C. Liang, and Geoffrey R. Martin. "Experimental Foundation Impedance Functions." Journal of Geotechnical Engineering 111, no. 6 (June 1985): 819–22. http://dx.doi.org/10.1061/(asce)0733-9410(1985)111:6(819).

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2

Lian, Jiang, Dong, Zhao, and Zhao. "Dynamic Impedance of the Wide-Shallow Bucket Foundation for Offshore Wind Turbine using Coupled Finite–Infinite Element Method." Energies 12, no. 22 (November 16, 2019): 4370. http://dx.doi.org/10.3390/en12224370.

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The dynamic impedances of foundation play an important role in the dynamic behavior and structural stability of offshore wind turbines (OWT). Though the behaviors of bucket foundation, which are considered as a relatively innovative foundation type under static loading, have been extensively investigated, the corresponding dynamic performances were neglected in previous research. This study focuses on the dynamic impedances of wide-shallow bucket foundations (WSBF) under the horizontal and rocking loads. Firstly, the numerical model was established to obtain the dynamic impedances of WSBF using the coupled finite-infinite element technique (FE-IFE). The crucial parameters affecting the dynamic responses of WSBF are investigated. It is shown that the skirt length mainly affects the rocking dynamic impedance and the diameter significantly affects the horizontal and coupling impedances, especially when the diameter is larger than 34 m. The overall dynamic responses of WSBF are profoundly affected by the relative soil thickness and the multi-layer soil stiffness. Additionally, dynamic impedances of WSBF are insensitive to the homogeneous soil stiffness. Lastly, the safety threshold curve was calculated according to the OWT, which can provide essential reference for the design of the OWT supported by large scale WSBF.

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3

Crouse, C. B., Behnam Hushmand, J. Enrique Luco, and H. L. Wong. "Foundation Impedance Functions: Theory Versus Experiment." Journal of Geotechnical Engineering 116, no. 3 (March 1990): 432–49. http://dx.doi.org/10.1061/(asce)0733-9410(1990)116:3(432).

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4

Ashoori, Taha, and Keivan Pakiman. "Dynamic Response of Different Types of Shallow Foundation over Sandy Soils to Horizontal Harmonic Loading." International Journal of Geotechnical Earthquake Engineering 6, no. 1 (January 2015): 1–14. http://dx.doi.org/10.4018/ijgee.2015010101.

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Increasing requirements of industries and research institutes to analytically results of interaction soil-foundation related systems, reveals the importance of the dynamic impedance functions than ever before. The dynamic impedance function relations are presented for mass less rigid foundations which is possible to obtain dynamic response of foundations for different frequencies and masses accordingly. In this study, the dynamic impedance functions were investigated using physical modeling tests on sandy soil with finite thickness soil stratum over bedrock. The tests were carried out inside a steel container of dimensions 1×1×0.8m in length, width and height respectively which was filled into container with Babolsar sand by using air – pluviation technique after calibration test with relative density of 55.1 percent. The selected foundations were square and circular with same surface area and rectangular with length to width ratio of 2 that were investigated to determine effects of shape, inertia, embedment ratio, dynamic force amplitude and bedrock on horizontal impedance.

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5

Wang, Hong Fang, Jiang Chun Hu, and Zhen Xia Yuan. "The Mathematical Foundation of Rock Electrochemical Impedance Spectroscopy." Advanced Materials Research 446-449 (January 2012): 1703–8. http://dx.doi.org/10.4028/www.scientific.net/amr.446-449.1703.

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The electromagnetic characteristics of rock and ore play an important role in resources, engineering and environmental fields. The high frequency part of rock electrochemical impedance spectroscopy can reveal its crack characteristics according to the test results and rock physical model and equivalent circuit. The mathematical foundation of high frequency part of rock electrochemical impedance spectroscopy is studied, and the ideal Nyquist figure is obtained from that, and the response characteristics of rock electrochemical impedance spectroscopy volume arc are been proofed. It provides the theory basis for further study rock electrochemical detection technology.

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6

He, Fang Ding, Guang Jun Guo, and Yang Yang. "Research on Dynamic Impedance Function for Horizontal Vibration of Single Pile." Applied Mechanics and Materials 90-93 (September 2011): 393–401. http://dx.doi.org/10.4028/www.scientific.net/amm.90-93.393.

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The horizontal vibration characteristic of the pile foundation is a key technology in dynamic design of foundation engineering. By researching on the horizontal harmonic loads in layered foundation, use horizontal vibration answers of buried foundation to deal with horizontal vibration impedance problems of pile tip. The transition matrix can be used to analyze the dynamic impedance function for horizontal vibration of pile foundation in layered foundation. And results in the paper is checked with traditional methods, which shows the both results fitting well.

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7

LIOU, Gin-Show. "IMPEDANCE FOR RIGID SQUARE FOUNDATION ON LAYERED MEDIUM." Doboku Gakkai Ronbunshu, no. 471 (1993): 47–57. http://dx.doi.org/10.2208/jscej.1993.471_47.

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8

Wang, Hong Fang, Jiang Chun Hu, and Zhen Xia Yuan. "The Mathematical Foundation of Rock Electrochemical Impedance Spectroscopy." Advanced Materials Research 446-449 (January 2012): 1703–8. http://dx.doi.org/10.4028/scientific5/amr.446-449.1703.

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9

Luco, J. E., and H. L. Wong. "Identification of Soil Properties from Foundation Impedance Functions." Journal of Geotechnical Engineering 118, no. 5 (May 1992): 780–95. http://dx.doi.org/10.1061/(asce)0733-9410(1992)118:5(780).

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10

Ahmad, S., and A. K. Rupani. "Horizontal impedance of square foundation in layered soil." Soil Dynamics and Earthquake Engineering 18, no. 1 (January 1999): 59–69. http://dx.doi.org/10.1016/s0267-7261(98)00028-1.

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11

Messioud, Salah, Badreddine Sbartai, and Daniel Dias. "Estimation of Dynamic Impedance of the Soil–Pile–Slab and Soil–Pile–Mattress–Slab Systems." International Journal of Structural Stability and Dynamics 17, no. 06 (August 2017): 1750057. http://dx.doi.org/10.1142/s0219455417500572.

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A 3D finite-element model for the dynamic analysis of soil–pile–slab is presented, with the soil–pile–mattress–slab interaction included in studying the dynamic behavior of the rigid–pile–reinforced soils. The soil, piles, and mattress are represented as continuum solids, and the slab is represented by structural plate elements. Quiet boundaries are placed at the boundaries of the model to avoid wave reflection. The formulation is based on the sub-structure method. Different geometric configurations are studied in terms of dynamic impedance. The numerical results are presented to show the influence of the mattress stiffness and the pile–soil contact conditions on the dynamic response of the foundation system. The horizontal and vertical impedances of the pile foundations are presented with the results compared with those available in previous studies.

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12

Taciroglu, Ertugrul, Mehmet Çelebi, S. Farid Ghahari, and Fariba Abazarsa. "An Investigation of Soil-Structure Interaction Effects Observed at the MIT Green Building." Earthquake Spectra 32, no. 4 (November 2016): 2425–48. http://dx.doi.org/10.1193/072215eqs118m.

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The soil-foundation impedance function of the MIT Green Building is identified from its response signals recorded during an earthquake. Estimation of foundation impedance functions from seismic response signals is a challenging task, because: (1) the foundation input motions (FIMs) are not directly measurable, (2) the as-built properties of the super-structure are only approximately known, and (3) the soil-foundation impedance functions are inherently frequency-dependent. In the present study, aforementioned difficulties are circumvented by using, in succession, a blind modal identification (BMID) method, a simplified Timoshenko beam model (TBM), and a parametric updating of transfer functions (TFs). First, the flexible-base modal properties of the building are identified from response signals using the BMID method. Then, a flexible-base TBM is updated using the identified modal data. Finally, the frequency-dependent soil-foundation impedance function is estimated by minimizing the discrepancy between TFs (of pairs instrumented floors) that are (1) obtained experimentally from earthquake data and (2) analytically from the updated TBM. Using the fully identified flexible-base TBM, the FIMs as well as building responses at locations without instruments can be predicted, as demonstrated in the present study.

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13

Wang, Chenyu, Hong Qiao, Yi Wang, and Xianting Du. "Numerical Algorithm for Dynamic Impedance of Bridge Pile-Group Foundation and Its Validation." Algorithms 14, no. 8 (August 20, 2021): 247. http://dx.doi.org/10.3390/a14080247.

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The characteristics of bridge pile-group foundation have a significant influence on the dynamic performance of the superstructure. Most of the existing analysis methods for the pile-group foundation impedance take the trait of strong specialty, which cannot be generalized in practical projects. Therefore, a project-oriented numerical solution algorithm is proposed to compute the dynamic impedance of bridge pile-group foundation. Based on the theory of viscous-spring artificial boundary, the derivation and solution of the impedance function are transferred to numerical modeling and harmonic analysis, which can be carried out through the finite element method. By taking a typical pile-group foundation as a case study, the results based on the algorithm are compared with those from existing literature. Moreover, an impact experiment of a real pile-group foundation was implemented, the results of which are also compared with those resulting from the proposed numerical algorithm. Both comparisons show that the proposed numerical algorithm satisfies engineering precision, thus showing good effectiveness in application.

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14

Gajan, Sivapalan, Prishati Raychowdhury, Tara C. Hutchinson, Bruce L. Kutter, and Jonathan P. Stewart. "Application and Validation of Practical Tools for Nonlinear Soil-Foundation Interaction Analysis." Earthquake Spectra 26, no. 1 (February 2010): 111–29. http://dx.doi.org/10.1193/1.3263242.

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Practical guidelines for characterization of soil-structure interaction (SSI) effects for shallow foundations are typically based on representing foundation-soil interaction in terms of viscoelastic impedance functions that describe stiffness and damping characteristics. Relatively advanced tools can describe nonlinear soil-foundation behavior, including temporary gap formation, foundation settlement and sliding, and hysteretic energy dissipation. We review two tools that describe such effects for shallow foundations and that are implemented in the computational platform OpenSees: a beam-on-nonlinear-Winkler foundation (BNWF) model and a contact interface model (CIM). We review input parameters and recommend parameter selection protocols. Model performance with the recommended protocols is evaluated through model-to-model comparisons for a hypothetical shear wall building resting on clay and model-data comparisons for several centrifuge test specimens on sand. The models describe generally consistent moment-rotation behavior, although shear-sliding and settlement behaviors deviate depending on the degree of foundation uplift. Pronounced uplift couples the moment and shear responses, often resulting in significant shear sliding and settlements. Such effects can be mitigated through the lateral connection of foundation elements with tie beams.

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15

Chen, Yang, Wen Zhao, Pengjiao Jia, Jianyong Han, and Yongping Guan. "Dynamic Behavior of an Embedded Foundation under Horizontal Vibration in a Poroelastic Half-Space." Applied Sciences 9, no. 4 (February 20, 2019): 740. http://dx.doi.org/10.3390/app9040740.

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More and more huge embedded foundations are used in large-span bridges, such as caisson foundations and anchorage open caisson foundations. Most of the embedded foundations are undergoing horizontal vibration forces, that is, wind and wave forces or other types of dynamic forces. The embedded foundations are regarded as rigid due to its high stiffness and small deformation during the forcing process. The performance of a rigid, massive, cylindrical foundation embedded in a poroelastic half-space is investigated by an analytical method developed in this paper. The mixed boundary problem is solved by reducing the dual integral equations to a pair of Fredholm integral equations of the second kind. The numerical results are compared with existing solutions in order to assess the accuracy of the presented method. To further demonstrate the applicability of this method, parametric studies are performed to evaluate the dynamic response of the embedded foundation under horizontal vibration. The horizontal dynamic impedance and response factor of the embedded foundation are examined based on different embedment ratio, foundation mass ratio, relative stiffness, and poroelastic material properties versus nondimensional frequency. The results of this study can be adapted to investigate the horizontal vibration responses of a foundation embedded in poroelastic half-space.

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16

Wang, Jue, Ding Zhou, Wei Qing Liu, and Shu Guang Wang. "Rocking Response of a Surface-Supported Strip Foundation under a Harmonic Swaying Force." Applied Mechanics and Materials 226-228 (November 2012): 1453–57. http://dx.doi.org/10.4028/www.scientific.net/amm.226-228.1453.

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This paper presents an accurate analytical method to obtain the rocking impedance function of a surface-supported strip foundation. The Green’s functions of the elastic half-space under concentrated or uniform loads with infinite length are derived and an elaborate integration method is used to calculate the multi-value improper integral. The interface between the foundation and the supporting medium is divided into a number of strip units. The rocking impedance function is solved by adding the moments in every strip, based on the fact that the vertical displacement of each unit can be uniquely determined by the rotation amplitude of the rigid foundation. Excellent convergence has been observed. Comparing the numerical results to those obtained by the thin layer method, good agreements are achieved. Finally, the effect of the Poisson’s ratio on the rocking impedance function of the strip foundation is discussed in detail.

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17

Lee, Doo-Ho, Bong-Ki Kim, Joung-Woo Byun, and Hyun-Sil Kim. "Impedance Analysis of Ship Equipment Foundation and Its Verification." Transactions of the Korean Society for Noise and Vibration Engineering 21, no. 5 (May 20, 2011): 393–99. http://dx.doi.org/10.5050/ksnve.2011.21.5.393.

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18

Şafak, Erdal. "Time-domain representation of frequency-dependent foundation impedance functions." Soil Dynamics and Earthquake Engineering 26, no. 1 (January 2006): 65–70. http://dx.doi.org/10.1016/j.soildyn.2005.08.004.

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19

Liou, Gin-Show, and I. L. Chung. "Impedance matrices for circular foundation embedded in layered medium." Soil Dynamics and Earthquake Engineering 29, no. 4 (April 2009): 677–92. http://dx.doi.org/10.1016/j.soildyn.2008.07.004.

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20

Liou, Gin‐Show, and Pao‐Han Huang. "Effect of Flexibility on Impedance Functions for Circular Foundation." Journal of Engineering Mechanics 120, no. 7 (July 1994): 1429–46. http://dx.doi.org/10.1061/(asce)0733-9399(1994)120:7(1429).

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21

Chen, Lin. "Dynamic Interaction Between Rigid Surface Foundations on Multi-Layered Half Space." International Journal of Structural Stability and Dynamics 16, no. 05 (April 27, 2016): 1550004. http://dx.doi.org/10.1142/s0219455415500042.

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A numerical approach is presented to calculate the dynamic response of a group of rigid surface foundations. The formulation is unconditionally stable and has the computational simplicity with only the algebraic calculations involved. It imposes no limit to the foundation shape, foundation separations, thickness of the layered medium and magnitude of frequency. In the analysis, the foundation–ground interface is discretized into a number of sub square-regions. The Green’s function, which is obtained by the Fourier–Bessel transform and precise integration method, is employed to calculate the dynamic response of each sub-region. Finally, a system of linear algebraic equation in terms of the contact forces within each sub-region is observed, which leads to the desired dynamic impedance functions of the foundations. Comparison is carried out between the proposed method and the solutions available in the literature. Parametric studies on the dynamic interaction between adjacent foundations are also described. Addressed in this study are the effects of the distance and direction of foundation alignment. Several conclusions are drawn the significance of each factor. Illustrative results for a case of several closely-spaced foundations are also presented. Although the dynamic interaction analysis of foundations is concerned here, further applications of this approach can be extended to the interaction analysis of structures.

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22

Amendola, C., F. de Silva, A. Vratsikidis, D. Pitilakis, A. Anastasiadis, and F. Silvestri. "Foundation impedance functions from full-scale soil-structure interaction tests." Soil Dynamics and Earthquake Engineering 141 (February 2021): 106523. http://dx.doi.org/10.1016/j.soildyn.2020.106523.

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23

Harte, M., and B. Basu. "Foundation impedance and tower transfer functions for offshore wind turbines." Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics 227, no. 2 (February 14, 2013): 150–61. http://dx.doi.org/10.1177/1464419312473056.

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24

Saitoh, Masato, and Hiroyuki Watanabe. "Effects of Flexibility on Rocking Impedance of Deeply Embedded Foundation." Journal of Geotechnical and Geoenvironmental Engineering 130, no. 4 (April 2004): 438–45. http://dx.doi.org/10.1061/(asce)1090-0241(2004)130:4(438).

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25

Kumar, Sunil, Vikas Rastogi, and Pardeep Gupta. "A hybrid impedance control scheme for underwater welding robots with a passive foundation in the controller domain." SIMULATION 93, no. 7 (February 1, 2017): 619–30. http://dx.doi.org/10.1177/0037549717693687.

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A hybrid impedance control scheme for the force and position control of an end-effector is presented in this paper. The interaction of the end-effector is controlled using a passive foundation with compensation gain. For obtaining the steady state, a proportional–integral–derivative controller is tuned with an impedance controller. The hybrid impedance controller is implemented on a terrestrial (ground) single-arm robot manipulator. The modeling is done by creating a bond graph model and efficacy is substantiated through simulation results. Further, the hybrid impedance control scheme is applied on a two-link flexible arm underwater robot manipulator for welding applications. Underwater conditions, such as hydrodynamic forces, buoyancy forces, and other disturbances, are considered in the modeling. During interaction, the minimum distance from the virtual wall is maintained. A simulation study is carried out, which reveals some effective stability of the system.

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26

Badreddine, Sbartai, and Kamel Goudjil. "Prediction of Dynamic Impedances Functions Using an Artificial Neural Network (ANN)." Applied Mechanics and Materials 170-173 (May 2012): 3588–93. http://dx.doi.org/10.4028/www.scientific.net/amm.170-173.3588.

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Artificial Neural Networks (ANN) has seen an explosion of interest over the last few years. Indeed, anywhere that there are problems of prediction, classification or control, neural networks are being introduced. Hence, the main objective of this paper is to develop a model to predict the response of the soil-structure interaction system without using the calculate code based on sophisticate numerical methods by the employment of a statistical approach based on an Artificial Neural Network model (ANN). In this study, a data base which relates the impedance functions to the geometrics characteristic of the foundation and the dynamic properties of the soil is implemented. This leads to develop a neural network model to predict impedances functions (all modes) of a rectangular surface foundation. Then the results are compared with unused data to check the ANN model’s validity.

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27

Ren, Yafeng, Shan Chang, and Geng Liu. "Study on low vibration isolator arrangement of marine gearboxes based on an impedance model." Transactions of the Canadian Society for Mechanical Engineering 44, no. 4 (December 1, 2020): 580–91. http://dx.doi.org/10.1139/tcsme-2019-0259.

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To reduce the underwater noise of ships, gearboxes are usually flexibly installed on the ship’s foundation. A reasonable isolator arrangement can effectively reduce the vibration transmitted from the gears to the foundation. In this paper, a dynamic model of a single-stage vibration-isolated gear system is established based on an impedance synthesis approach. This model is a multiple degrees of freedom, multi-mount, and flexible model that can take into account the local stiffness of the housing and foundation. By studying the influence of installation span, installation offset, and number of isolators on the vibrations of the ship’s foundation, it was determined that reducing isolator span is beneficial to isolation, increasing isolator offset can slightly reduce vibration, increasing the number of isolators does not always increase vibration, and the local stiffness characteristics of the housing and foundation have a greater influence than other factors on the isolation performance.

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28

Joshi, Sharad, Ishwer Datt Gupta, Lalitha R. Pattanur, and Pranesh B. Murnal. "Investigating the Effect of Depth and Impedance of Foundation Rock in Seismic Analysis of Gravity Dams." International Journal of Geotechnical Earthquake Engineering 5, no. 2 (July 2014): 1–18. http://dx.doi.org/10.4018/ijgee.2014070101.

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The inhomogenieties of the foundation can be modeled explicitly in standard FEM procedure, however, the results vary significantly with the extent of foundation block modeled and mechanism of applying the input earthquake excitation. The substructure approach provides mathematically exact solution but assumes average properties for the entire foundation as viscoelastic half space. This paper has carried out detailed investigations with varying impedance contrasts and different size of foundation block to show that the results, with suitably deconvoluted free-field ground acceleration time-history applied at the base of foundation block in the FEM approach, are in good agreement with the substructure approach. However, the other variants of the FEM approach may lead to erroneous and overestimated stresses in the dam body. As the foundation of gravity dams can generally be approximated as an equivalent homogeneous half-space, the more accurate and efficient substructure approach can be used to model the dam-foundation rock interaction (SSI) effects in most practical situations.

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29

Trofymchuk, Oleksandr, and Oleh Savytskyi. "Vertical Impedance of Rigid Shallow Foundation on Layered Water-Saturated Soil." Modeling, Control and Information Technologies, no. 3 (November 6, 2019): 165–67. http://dx.doi.org/10.31713/mcit.2019.48.

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Methods have been developed for numerical analysis the vertical oscillations of rigid plate with a liquidimpermeable sole rested on the layer (Biot’s model) with a rigidly restrained lower edge. The plate sole is liquid-impermeable. The analysis of the impedance functions depending on the oscillation frequency, the geometry of the system and the mechanical parameters of the soil model is carried out.

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30

Yong, Y., Ruichong Zhang, and J. Yu. "Motion of foundation on a layered soil medium — I. Impedance characteristics." Soil Dynamics and Earthquake Engineering 16, no. 5 (January 1997): 295–306. http://dx.doi.org/10.1016/s0267-7261(97)00006-7.

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31

Wang, Jue, Ding Zhou, Weiqing Liu, and Shuguang Wang. "Nested Lumped-Parameter Model for Foundation with Strongly Frequency-dependent Impedance." Journal of Earthquake Engineering 20, no. 6 (February 6, 2016): 975–91. http://dx.doi.org/10.1080/13632469.2015.1109568.

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32

Lund, J. W., and Z. Wang. "Application of the Riccati Method to Rotor Dynamic Analysis of Long Shafts on a Flexible Foundation." Journal of Vibration and Acoustics 108, no. 2 (April 1, 1986): 177–81. http://dx.doi.org/10.1115/1.3269319.

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A method is described for calculating critical speeds, unbalance response and damped natural frequencies of long rotors on a flexible foundation. The shaft and the foundation are calculated separately and coupled at the bearings through impedance matching. Included in the analysis is also a method for representing the shaft response by an expansion in its free-free modes.

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33

Gatscher, Jeffrey A., and Grzegorz Kawiecki. "Comparison of Mechanical Impedance Methods for Vibration Simulation." Shock and Vibration 3, no. 3 (1996): 223–32. http://dx.doi.org/10.1155/1996/871696.

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The work presented here explored the detrimental consequences that resulted when mechanical impedance effects were not considered in relating vibration test requirements with field measurements. The ways in which these effects can be considered were evaluated, and comparison of three impedance methods was accomplished based on a cumulative damage criterion. A test structure was used to simulate an equipment and support foundation system. Detailed finite element analysis was performed to aid in computation of cumulative damage totals. The results indicate that mechanical impedance methods can be effectively used to reproduce the field vibration environment in a laboratory test. The establishment of validated computer models, coupled with laboratory impedance measurements, can eliminate the overtesting problems inherent with constant motion, infinite impedance testing strategies.

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34

Liu, Jing, Jianke Du, Ji Wang, and Jiashi Yang. "Effects of surface impedance on current density in a piezoelectric resonator for impedance distribution sensing." Applied Mathematics and Mechanics 42, no. 5 (May 2021): 677–88. http://dx.doi.org/10.1007/s10483-021-2723-9.

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AbstractWe study the relationship between the surface mechanical load represented by distributed acoustic impedance and the current density distribution in a shear mode piezoelectric plate acoustic wave resonator. A theoretical analysis based on the theory of piezoelectricity and trigonometric series is performed. In the specific and basic case when the surface load is due to a local mass layer, numerical results show that the current density concentrates under the mass layer and is sensitive to the physical as well as geometric parameters of the mass layer such as its location and size. This provides the theoretical foundation for predicting the surface impedance pattern from the current density distribution, which is fundamental to the relevant acoustic wave sensors.

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35

Zahafi, Amina, and Mohamed Hadid. "Simplified frequency-independent model for vertical vibrations of surface circular foundations." World Journal of Engineering 16, no. 5 (October 7, 2019): 592–603. http://dx.doi.org/10.1108/wje-05-2019-0145.

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Purpose This paper aims to simplify a new frequency-independent model to calculate vertical vibration of rigid circular foundation resting on homogenous half-space and subjected to vertical harmonic excitation is presented in this paper. Design/methodology/approach The proposed model is an oscillator of single degree of freedom, which comprises a mass, a spring and a dashpot. In addition, a fictitious mass is added to the foundation. All coefficients are frequency-independent. The spring is equal to the static stiffness. Damping coefficient and fictitious mass are first calculated at resonance frequency where the response is maximal. Then, using a curve fitting technique the general formulas of damping and fictitious mass frequency-independent are established. Findings The validity of the proposed method is checked by comparing the predicted response with those obtained by the half-space theory. The dynamic responses of the new simplified model are also compared with those obtained by some existing lumped-parameter models. Originality/value Using this new method, to calculate the dynamic response of foundations, the engineer only needs the geometrical and mechanical characteristics of the foundation (mass and radius) and the soil (density, shear modulus and the Poisson’s ratio) using just a simple calculator. Impedance functions will no longer be needed in this new simplified method. The methodology used for the development of the new simplified model can be applied for the resolution of other problems in dynamics of soil and foundation (superficial and embedded foundations of arbitrary shape, other modes of vibration and foundations resting on non-homogeneous soil).

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36

He, R., R. Y. S. Pak, and L. Z. Wang. "Elastic lateral dynamic impedance functions for a rigid cylindrical shell type foundation." International Journal for Numerical and Analytical Methods in Geomechanics 41, no. 4 (August 30, 2016): 508–26. http://dx.doi.org/10.1002/nag.2567.

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37

Cottereau, Régis, Didier Clouteau, and Christian Soize. "Probabilistic impedance of foundation: Impact of the seismic design on uncertain soils." Earthquake Engineering & Structural Dynamics 37, no. 6 (2008): 899–918. http://dx.doi.org/10.1002/eqe.794.

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38

Lou, M., A. Ghobarah, and T. S. Aziz. "An iterative method to evaluate the impedance matrix of finite-size foundation." Computers and Geotechnics 11, no. 2 (January 1991): 97–124. http://dx.doi.org/10.1016/0266-352x(91)90022-8.

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39

Gao, Yuan Sheng, Qiang Chen, Qiang Sun, Zhong Chen, and Wen Hai Zhang. "The Impedance Calculation Methods Using Damped Sinusoidal Signal." Advanced Materials Research 860-863 (December 2013): 2003–6. http://dx.doi.org/10.4028/www.scientific.net/amr.860-863.2003.

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There are large number of transient signals will be produced when the operation mode is changed. And the frequency of the transient signals distributed in wide range. The most of them are damped and oscillated. The impedance is a popular feature in power system, and it has been widely used in relay protection and fault location. So the impedance calculation based on the damped sinusoidal signal have been the important way to diagnosis the fault, locate the fault and so on. But the methods used now are based on the fundamental impedance calculation theory, lacking theoretical basis. In fact, the traditional methods for fundamental signal calculation are not appropriate for the quantitative analysis of damped sinusoidal signal. The paper analyzed the impedance calculation based on damped sinusoidal signal, combined the features of damped sinusoidal signals and the traditional impedance calculation method. The two typical signal analysis methods for damped sinusoidal signal extraction are used to calculate the accurate impedance based on the different extraction results. And the analysis laid a foundation for the impedance calculation using damped sinusoidal signals.

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Wen, Xuezhang, Fangyuan Zhou, Nobuo Fukuwa, and Hongping Zhu. "A simplified method for impedance and foundation input motion of a foundation supported by pile groups and its application." Computers and Geotechnics 69 (September 2015): 301–19. http://dx.doi.org/10.1016/j.compgeo.2015.06.004.

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Zhou, Fangyuan, Xuezhang Wen, Nobuo Fukuwa, and Hongping Zhu. "A simplified method of calculating the impedance and foundation input motion of foundations with a large number of piles." Soil Dynamics and Earthquake Engineering 78 (November 2015): 175–88. http://dx.doi.org/10.1016/j.soildyn.2015.08.003.

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Saitoh, Masato, Tomoya Saito, Toshifumi Hikima, Makoto Ozawa, and Keiichi Imanishi. "Representation of Soil-Foundation Systems and Its Application to Shaking Table Tests by Constructing a Mechanical Interface." Earthquake Spectra 29, no. 2 (May 2013): 547–71. http://dx.doi.org/10.1193/1.4000142.

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Experimental studies on the dynamic response of structures comprising soil-foundation systems require an appropriately constructed soil-foundation model below the superstructures in order to properly estimate structural responses. In most studies, applying a small scaling is necessary for constructing the entire structural system, since there is limited space on shaking tables. This constraint has been a hindrance in experimental studies. Thus this study proposes a mechanical interface (MI) that represents the impedance characteristics of a 3 × 5 pile group embedded in a layered soil medium. The MI is constructed on the basis of lumped parameter models with gyro-mass elements. This element is mechanically realized in the MI using a rotational mass in combination with coupling gears. The results show that the MI properly simulates the impedance functions with frequency-dependent oscillations, and shaking table tests using the MI for an inelastic structure are demonstrated.

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Han, Zejun, Gao Lin, and Jianbo Li. "Dynamic Impedance Functions for Arbitrary-Shaped Rigid Foundation Embedded in Anisotropic Multilayered Soil." Journal of Engineering Mechanics 141, no. 11 (November 2015): 04015045. http://dx.doi.org/10.1061/(asce)em.1943-7889.0000915.

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Srinivasan, M. G., C. A. Kot, and B. J. Hsieh. "Determination of soil impedance functions from vibration-test response of a circular foundation." Soil Dynamics and Earthquake Engineering 10, no. 4 (May 1991): 212–27. http://dx.doi.org/10.1016/0267-7261(91)90035-x.

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Srinivasan, M. G., C. A. Kot, and B. J. Hsieh. "Determination of soil impedance functions from vibration-test response of a circular foundation." International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts 28, no. 6 (November 1991): A387. http://dx.doi.org/10.1016/0148-9062(91)91573-a.

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Mezeh, Reda, Marwan Sadek, Fadi Hage Chehade, and Isam Shahrour. "A frequency and velocity-dependent impedance method for prediction of rail/foundation dynamics." Earthquake Engineering and Engineering Vibration 20, no. 1 (January 2021): 101–11. http://dx.doi.org/10.1007/s11803-021-2008-9.

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Nikulin, S. V., V. A. Petrov, and D. A. Sakharov. "Analysis of the Dynamics of the Electric Capacitance of a Cell Monolayer at the Late Stages of Caco-2 cell Differentiation." Biotekhnologiya 35, no. 6 (2019): 87–90. http://dx.doi.org/10.21519/0234-2758-2019-35-6-87-90.

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The real-time monitoring of electric capacitance (impedance spectroscopy) allowed obtaining evidence that structures which look like intestinal villi can be formed during the cultivation under static conditions as well as during the cultivation in microfluidic chips. It was shown in this work via transcriptome analysis that the Hh signaling pathway is involved in the formation of villus-like structures in vitro, which was previously shown for their formation in vivo. impedance spectroscopy, intestine, villi, electric capacitance, Hh The study was funded by the Russian Science Foundation (Project 16-19-10597).

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Yeh, C. S., T. J. Teng, and W. I. Liao. "Dynamic Response of a Hemispherical Foundation Embedded in an Elastic Half-Space." Journal of Pressure Vessel Technology 120, no. 4 (November 1, 1998): 343–48. http://dx.doi.org/10.1115/1.2842341.

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The dynamic response of a massless rigid hemispherical foundation embedded in a uniform homogeneous elastic half-space is considered in this study. The foundation is subjected to external forces, moments, plane harmonic P and SH waves, respectively. The series solutions are constructed by three sequences of Lamb’s singular solutions which satisfy the traction-free conditions on ground surface and radiation conditions at infinity, automatically, and their coefficients are determined by the boundary conditions along the soil-foundation interface in the least square sense. The fictitious eigen-frequencies, which arise in integral equation method, will not appear in the numerical calculation by the proposed method. The impedance functions which characterize the response of the foundation to external harmonic forces and moments at low and intermediate frequencies are calculated and the translational and rocking responses of the foundation when subjected to plane P and SH waves are also presented and discussed in detail.

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Harichane, Zamila, Mohamed Elhebib Guellil, and Hamid Gadouri. "Benefits of Probabilistic Soil-Foundation-Structure Interaction Analysis." International Journal of Geotechnical Earthquake Engineering 9, no. 1 (January 2018): 42–64. http://dx.doi.org/10.4018/ijgee.2018010103.

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The present article highlights the beneficial effect of considering soil and structure parameters uncertainties on the soil-structure response. The impedance functions of a circular foundation resting on a random soil layer over a homogeneous half-space were obtained by using cone models. The obtained results showed that the randomness of the layer's thickness and the shear wave velocity significantly affected the mean spring coefficients whereby coefficients of variation (COV) of 10% and 20% in these parameters reduced the mean spring coefficients about 32% and 40%, respectively, for the horizontal motion and about 12.5% and 25%, respectively, for the rocking motion. The sensitivity of the mean structural response to the randomness effect was obtained to be more pronounced to structural parameters than to soil parameters. In addition, 20% COV in both soil and structure parameters reduced the mean structural response about 39%, translated by an increase in the damping of the coupled system which may be considered as a beneficial effect from code provisions point of view.

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Liu, Chun Lin, Shuo Zhang, Meng Xiong Tang, He Song Hu, Zhen Kun Hou, and Hang Chen. "Vertical Dynamic Response of Rock-Socketed Piles in a Layered Foundation." E3S Web of Conferences 173 (2020): 04002. http://dx.doi.org/10.1051/e3sconf/202017304002.

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A simplified method is presented to investigate the dynamic response of rock-socketed piles embedded in a layered foundation. The finite element method is utilized to derive the dynamic stiffness matrix equations of the pile modelled as a 1D bar, and the exact stiffness matrix method is employed to establish the flexibility matrix equations of the foundation modelled as a 3D body. According to the pilesoil interaction condition, these matrices are incorporated together to obtain the solution for the dynamic response of rock-socketed piles. Finally, some numerical results are given to illustrate the influence of rocksocketed depth on the pile vertical impedance.

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