Parametric Study on the Interpretation of Wave Velocity Obtained by Seismic Interferometry in Beam‐Like Buildings

2019 ◽  
Vol 109 (5) ◽  
pp. 1829-1842 ◽  
Author(s):  
Philippe Guéguen ◽  
E. Diego Mercerat ◽  
Felipe Alarcon
Keyword(s):  
Timoshenko Beam ◽  
Parametric Study ◽  
Soil Structure ◽  
Pulse Wave ◽  
Pure Shear ◽  
Horizontal Displacement ◽  
Seismic Interferometry ◽  
Fixed Base ◽  
Time Histories ◽  
Bending Ratio

Abstract In this article, we propose an interpretation of the propagation velocities of the pulse wave obtained in vertical structures through seismic interferometry by deconvolution. The novelty of this article is to propose a parametric study applied to canonical finite‐element models of fixed‐base buildings from pure‐shear to pure‐bending beam‐like buildings, adjusted to equivalent Timoshenko beam‐like structures. For given input seismic motions, the time histories of the horizontal displacement at each floor are obtained and used to estimate the propagation velocity of the pulse wave by deconvolution. A frequency–wavenumber technique is used to highlight the dispersive characteristics of the pulse wave. The obtained velocity is compared with the theoretical dispersion curve of the Timoshenko beam‐like structure and interpreted according to the nature of the structure. We propose a corrective coefficient to link the first resonance frequency of the building to the velocity obtained by deconvolution, according to the shear‐to‐bending ratio. Finally, we compare specific Timoshenko beam models with a number of previously published studies on the experimental interpretation of velocity in real‐case buildings for which soil–structure interaction conditions are different from the fixed‐base conditions of the Timoshenko beam‐like structure.

Comparison of eigenanalysis and Ritz vector approaches for response spectrum analysis of soil-pile-bridge systems

2021 ◽  
Vol 17 (3-4) ◽  
pp. 89-100
Author(s):  
M. Davidson ◽  
A. Patil ◽  
S.A. Rosenfeld ◽  
Z. Zhu
Keyword(s):  
Spectrum Analysis ◽  
Soil Structure ◽  
Response Spectrum ◽  
Active Regions ◽  
Ritz Vector ◽  
Response Spectrum Analysis ◽  
Fixed Base ◽  
Potential Benefits ◽  
Eigenvectors And Eigenvalues ◽  
Vector Approach

Frequency-based analysis techniques such as response spectrum analysis (RSA) are widely used for designing bridges in seismically active regions. Two well-known analysis procedures that underlie RSA are the solution of the eigenproblem and the approximation of the solution to the eigenproblem (i.e., approximation of eigenvectors and eigenvalues) through use of force-dependent Ritz vectors. While frequency-based methods have achieved widespread adoption in practice, certain simplifications remain common, such as neglecting soil-structure interaction (SSI) due to a fixed-base assumption. In the present study, frequency-based techniques packaged within a research version of a design-oriented computational tool are employed to analyze, assess, and compare results obtained from RSA with use of the eigenanalysis, and separately, Ritz vector approaches. Importantly, for the bridge configurations analyzed, SSI is taken into account. As outcomes, the potential benefits of the Ritz vector approach (as well as modeling strategies) are demonstrated. The study outcomes are intended to aid practicing engineers when the need to account for SSI is recognized as pertinent to a given bridge seismic design application.

Dynamic structure-soil-structure interaction

1973 ◽  
Vol 63 (4) ◽  
pp. 1289-1303
Author(s):  
J. Enrique Luco ◽  
Luis Contesse
Keyword(s):  
Soil Structure ◽  
Natural Frequencies ◽  
Shear Walls ◽  
Dynamic Structure ◽  
Soil Structure Interaction ◽  
Sh Wave ◽  
Low Frequencies ◽  
High Frequencies ◽  
State Response ◽  
Fixed Base

abstract A study is made of the dynamic interaction, through the soil, between two parallel infinite shear walls placed on rigid foundations. The steady-state response of both structures for a vertically incident SH wave is obtained and compared with the corresponding values resulting from consideration of only one structure. It is found that the additional interaction effects caused by the presence of a second structure are especially important at low frequencies and in the neighborhood of the fixed-base natural frequencies of the second structure. For high frequencies it is sufficient to consider the interaction between each structure and the soil, ignoring the presence of other structures.

Study of Pushover Analysis on RC Framed Structure with Underground Structure Considering the Effects of Soil Structure Interaction

2020 ◽  
Vol 8 ◽  
pp. 22-29
Author(s):  
Nasala Dongol ◽  
Prachand Man Pradhan ◽  
Suman Manandhar
Keyword(s):  
Soil Structure ◽  
Response Spectrum ◽  
Underground Structure ◽  
Pushover Analysis ◽  
Standard Penetration Test ◽  
Soil Structure Interaction ◽  
Base System ◽  
Building Site ◽  
Structure Interaction ◽  
Fixed Base

This study states that the effects of soil structure interaction on the Reinforced Concrete (RC) framed structures is directly influenced by the soil properties of the site. Here, one preexisting structure is taken for the study. The building is a hospital building with two underground basements. Taking into account the actual soil condition of building site, this study provides idea on the soil structure interaction on the structure The properties of springs are calculated from different standard penetration test (SPT) values, Poisson’s ratio and elasticity of soil along the depth of the soil. Entire soil-foundation-structure system is modelled and analyzed using spring approach. Static analysis, response spectrum analysis and pushover analysis (PA) are done in order to find the variations in natural periods, base shears and deflections of the structures by incorporating soil flexibility as compared to structures with conventional fixed base. Pushover analysis is done to evaluate the performance of the structure when modelled in fixed base and spring base system.

scholarly journals Effect of Soil-Structure Interaction on the Seismic Response of Existing Low and Mid-Rise RC Buildings

2020 ◽  
Vol 10 (23) ◽  
pp. 8357
Author(s):  
Ibrahim Oz ◽  
Sevket Murat Senel ◽  
Mehmet Palanci ◽  
Ali Kalkan
Keyword(s):  
Seismic Response ◽  
Seismic Performance ◽  
Soil Structure ◽  
Soft Soil ◽  
Soil Structure Interaction ◽  
Soil Conditions ◽  
Existing Buildings ◽  
Structure Interaction ◽  
Fixed Base ◽  
New Buildings

Reconnaissance studies performed after destructive earthquakes have shown that seismic performance of existing buildings, especially constructed on weak soils, is significantly low. This situation implies the negative effects of soil-structure interaction on the seismic performance of buildings. In order to investigate these effects, 40 existing buildings from Turkey were selected and nonlinear models were constructed by considering fixed-base and stiff, moderate and soft soil conditions. Buildings designed before and after Turkish Earthquake code of 1998 were grouped as old and new buildings, respectively. Different soil conditions classified according to shear wave velocities were reflected by using substructure method. Inelastic deformation demands were obtained by using nonlinear time history analysis and 20 real acceleration records selected from major earthquakes were used. The results have shown that soil-structure interaction, especially in soft soil cases, significantly affects the seismic response of old buildings. The most significant increase in drift demands occurred in first stories and the results corresponding to fixed-base, stiff and moderate cases are closer to each other with respect to soft soil cases. Distribution of results has indicated that effect of soil-structure interaction on the seismic performance of new buildings is limited with respect to old buildings.

Internal Explosions in Embedded Concrete Pipes

2011 ◽  
Vol 82 ◽  
pp. 452-457 ◽  
Author(s):  
Pamela Bonalumi ◽  
Matteo Colombo ◽  
Marco di Prisco
Keyword(s):  
Soil Structure ◽  
Soft Soil ◽  
High Energy ◽  
Radial Acceleration ◽  
Structure System ◽  
Concrete Pipe ◽  
Pressure Time ◽  
Time Histories ◽  
Solid Explosives ◽  
Thin Plastic

Blast tests on a full-scale concrete pipe embedded in soft soil were carried out to evaluate the behavior of the soil-structure system under the internal detonation of high-energy solid explosives. Two different stages were considered: the former focused on the detonation of a low entity charge within the pipe to maintain the concrete in the elastic regime and the latter concerned with adopting larger quantities of explosive to produce cracking and failure of the structure. Cylindrical charges ranging from few grams to hundreds of grams of a high-energy solid explosive were investigated and different tests were performed for each quantity by inserting the explosive charge in a cardboard cylinder hanged up in the middle of the pipe central segment by means of three thin plastic wires. The following quantities were measured in different sections along the pipe: side-on and reflected pressure-time histories at the inner surface of the structure, pipe radial acceleration, peak particle acceleration of the surrounding soil by means of accelerometers placed at different distances and depths from the section where the explosion occurred. The experimental results obtained during the performed blast tests are thus analyzed to understand the soil-structure system behavior under such fast transient dynamic phenomena.

Seismic behavior of structures considering uplift and soil–structure interaction

2017 ◽  
Vol 20 (11) ◽  
pp. 1712-1726
Author(s):  
Farhad Behnamfar ◽  
Seyyed Mohammad Mirhosseini ◽  
Hossein Alibabaei
Keyword(s):  
Seismic Behavior ◽  
Soil Structure ◽  
Nonlinear Dynamic Analysis ◽  
Steel Structures ◽  
Soil Structure Interaction ◽  
Structure Interaction ◽  
Nonlinear Seismic Response ◽  
Tensile Forces ◽  
Fixed Base ◽  
Flexible Base

A common assumption when analyzing a structure for earthquake forces is that the building is positively attached to a rigid ground so that it can sustain possible tensile forces without being detached, or uplifted, from its bearing points. Considering the facts that almost no tension can be transferred between a surface foundation and soil and soft soils interact with the supported structure during earthquakes, in this research, the effects of uplift and soil–structure interaction on nonlinear seismic response of structures are evaluated. Several reinforced concrete and steel structures under different suits of consistent ground motions are considered. The base of the buildings is modeled with vertical no-tension springs being nonlinear in compression. The total soil–structure interaction system is modeled within OpenSees, and the seismic behavior is evaluated using a nonlinear dynamic analysis. The nonlinear responses of buildings are determined and compared between three cases: fixed base, flexible base without uplift, and flexible base with uplift. The cases for which uplift in conjunction with soil–structure interaction should be considered are identified.

Probabilistic Seismic Soil Structure Interaction Analysis of the Mu¨hleberg Nuclear Power Plant Reactor and SUSAN Buildings

2010 ◽  
Author(s):  
David K. Nakaki ◽  
Philip S. Hashimoto ◽  
James J. Johnson ◽  
Yahya Bayraktarli ◽  
Olivier Zuchuat
Keyword(s):  
Power Plant ◽  
Nuclear Power ◽  
Soil Structure ◽  
Response Spectra ◽  
Soil Structure Interaction ◽  
Response Analysis ◽  
Structure Interaction ◽  
Fixed Base ◽  
Plant Reactor ◽  
Stiffness And Damping

Probabilistic seismic soil-structure interaction (SSI) analysis was performed for the Mu¨hleberg Nuclear Power Plant Reactor and SUSAN Buildings in support of the seismic probabilistic saftety assessment of the plant. An efficient hybrid method, employing computer programs SASSI2000 and CLASSI presented in a companion paper, was used in this analysis. The method takes advantage of the capability of SASSI2000 to analyze embedded structures with irregular geometry and the computational efficiency of CLASSI to rapidly perform the SSI response analysis of large structure models. Fixed base finite element models of the buildings were first developed from which the structure geometry, nodal masses, natural frequencies, and mode shapes were extracted. The structure embedments were modeled using SASSI2000. Impedance functions and scattering vectors were calculated by imposing rigid body constraints to the embedded foundation. The fixed base structure dynamic properties and the foundation impedances and scattering functions were input to CLASSI to perform the response analysis. The probabilistic analysis was performed following the Latin Hypercube Simulation (LHS) approach documented in NUREG/CR-2015. Variables defined by probability distributions were sampled according to a stratified sampling approach. The combination of the parameters for each simulation was determined by Latin Hypercube experimental design. Variables in the LHS included the earthquake ground acceleration time histories, structure stiffness and damping, and soil stiffness and damping. Thirty response simulations were performed using CLASSI in which the variable values were randomly selected. The use of CLASSI has the advantage that the response analysis simulations can be executed in a fraction of the time that would be required with SASSI2000 alone. For each simulation, in-structure response spectra (ISRS) were calculated at selected locations in the buildings. Probabilistic distributions, described by the median and 84th percentile response spectra, were calculated from the thirty simulations. The probabilistic ISRS are subsequently used in the seismic fragility evaluations of selected essential equipment.

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