scholarly journals Effect of Height Ratio and Mass Ratio on Structure—Soil—Structure Interaction of Two Structures Using Centrifugal Experiment

2019 ◽  
Vol 9 (3) ◽  
pp. 526 ◽  
Author(s):  
Van-Linh Ngo ◽  
Jae-Min Kim ◽  
Soo-Hyuk Chang ◽  
Changho Lee
Keyword(s):  
Soil Structure ◽  
Soil Structure Interaction ◽  
Geotechnical Centrifuge ◽  
Structure Interaction ◽  
Structure Response ◽  
Centrifuge Tests ◽  
Adjacent Structures ◽  
Soil Foundation ◽  
Period Lengthening ◽  
Significant Increment

: In a megacity, structure response during an earthquake could be increased or decreased due to effects from neighboring structures, through structure-soil-structure interaction (SSSI). In the present study, a series of dynamic geotechnical centrifuge tests are carried out to investigate SSSI effects on responses of structure with various characteristics of mass, height, and natural frequency. Experimental observations are focused on the effects of the distance between two structures, type, and peak acceleration of input excitation. A period lengthening is observed in the soil-foundation-structure interaction (SFSI) effects of all structures. It is monitored that an increment in response of smaller structure and a decrement in response of larger structure, compared to isolated structure, due to SSSI effects. Unfavorable distance reveals that the most significant increment in response of S2 structure occurred at approximately one-fourth of wavelength transmitted from the vibrating adjacent structure. More severe SSSI effects are found under a lower input earthquake acceleration. It is found that both height and mass ratios, between two adjacent structures, are particular parameters on SSSI, resulting in increment or reduction of structure response.

A Centrifuge Study of Seismic Structure-Soil-Structure Interaction on Liquefiable Ground and Implications for Design in Dense Urban Areas

2018 ◽  
Vol 34 (3) ◽  
pp. 1113-1134 ◽  
Author(s):  
Peter Kirkwood ◽  
Shideh Dashti
Keyword(s):  
Urban Areas ◽  
Soil Structure ◽  
Free Field ◽  
Mitigation Strategies ◽  
Soil Structure Interaction ◽  
Minimal Risk ◽  
Seismic Structure ◽  
Structure Interaction ◽  
Centrifuge Tests ◽  
Adjacent Structures

Current practice in seismic design often assumes free-field conditions for the estimation of liquefaction-induced building settlement. This is inaccurate, as a structure places additional stresses on the soil, resulting in changes to the spatial and temporal occurrence of liquefaction, accelerations, and deformations. Further complications arise in dense urban environments where closely spaced structures may interact through structure-soil-structure interaction (SSSI). Previous studies have shown that SSSI may have positive or negative effects on the response of adjacent structures in terms of permanent settlement, rotation, and flexural deformations. However, little is known regarding how to maximize the benefits of SSSI with minimal risk of adverse consequence. In this study, centrifuge tests were conducted on both isolated and closely spaced structures to identify how the building separation and ground motion characteristics affect the response of adjacent structures founded on a layered, liquefiable soil profile. Results indicate that properly planned configurations and interactions may be employed in combination with traditional mitigation strategies to improve the settlement-rotation response of adjacent structures, while also reducing the demand imposed on the superstructure.

scholarly journals Centrifuge testing of soil–structure interaction effects on cyclic failure potential of fine-grained soil

2021 ◽  
pp. 875529302098197
Author(s):  
Jason M Buenker ◽  
Scott J Brandenberg ◽  
Jonathan P Stewart
Keyword(s):  
Soil Structure ◽  
Interaction Effects ◽  
Soil Structure Interaction ◽  
Centrifuge Testing ◽  
Geotechnical Centrifuge ◽  
Structure Interaction ◽  
Fine Grained ◽  
Stiffness Properties ◽  
Fine Grained Soil ◽  
Strip Footings

We describe two experiments performed on a 9-m-radius geotechnical centrifuge to evaluate dynamic soil–structure interaction effects on the cyclic failure potential of fine-grained soil. Each experiment incorporated three different structures with a range of mass and stiffness properties. Structures were founded on strip footings embedded in a thin layer of sand overlying lightly overconsolidated low-plasticity fine-grained soil. Shaking was applied to the base of the model container, consisting of scaled versions of recorded earthquake ground motions, sweep motions, and step waves. Data recorded during testing were processed and published on the platform DesignSafe. We describe the model configuration, sensor information, shaking events, and data processing procedures and present selected processed data to illustrate key model responses and to provide a benchmark for data use.

Effects of Slenderness and Fundamental Frequency on the Dynamic Response of Adjacent Structures

2019 ◽  
Vol 19 (09) ◽  
pp. 1950105
Author(s):  
Gonzalo Barrios ◽  
Vinuka Nanayakkara ◽  
Pramodya De Alwis ◽  
Nawawi Chouw
Keyword(s):  
Dynamic Response ◽  
Fundamental Frequency ◽  
Soil Structure ◽  
Numerical Models ◽  
Ground Motions ◽  
Soil Structure Interaction ◽  
Reference Case ◽  
Maximum Acceleration ◽  
Structure Interaction ◽  
Adjacent Structures

In conventional seismic design, the structure is often assumed to be fixed at the base. However, this assumption does not reflect reality. Furthermore, if the structure has close neighbors, the adjacent structures will alter the response of the structure considered. Investigations on soil–structure interaction and structure–soil–structure interaction have been performed mainly using numerical models. The present work addresses the dynamic response of adjacent single-degree-of-freedom models on a laminar box filled with sand. Impulse loads and simulated ground motions were applied. The standalone condition was also studied as a reference case. Models with different fundamental frequencies and slenderness were considered. Results from the impulse tests showed that the top displacement of the models with an adjacent structure was reduced compared with that of the standalone case. Changes in the fundamental frequency of the models due to the presence of an adjacent model were also observed. Results from ground motions showed amplification of the maximum acceleration and the top displacement of the models when both structures have a similar fundamental frequency.

A Study on the Embedment Effect in the Soil-Structure Interaction Analysis of the APR1400

2002 ◽  
Author(s):  
Young-Sun Jang ◽  
Kwang-Ho Joo ◽  
Chong-Hak Kim
Keyword(s):  
Nuclear Power ◽  
Soil Structure ◽  
Interaction Analysis ◽  
Response Spectra ◽  
Soil Structure Interaction ◽  
Soil Conditions ◽  
Structure Interaction ◽  
Structure Response ◽  
Parametric Analyses ◽  
Volume Method

The SSI (Soil-Structure Interaction) analyses are being performed for the APR1400 (Advanced Power Reactor 1400MWe, Old name - KNGR ; Korean Next Generation Reactor) design, because the APR1400 is developed as a Standard Nuclear Power Plant concept enveloping suitable soil conditions. For the SSI analyses, SASSI program which adopts the Flexible Volume Method is used. In the SSI analyses, there can be uncertainties by Bond and De-bond problem between the structure and lateral soil elements. According to ASCE Standard 4, one method to address this concern is to assume no connectivity between structure and lateral soil over the upper half of the embedment of 20ft (6m), whichever is less. This study is performed as a part of the parametric analyses for the APR1400 seismic analyses to address the concern of the potential embedment effect on the in-structure response spectra due to connectivity between structure and lateral soil. In this study, 4 model cases are analyzed to check the potential embedment effect — Full connection, 20ft no connectivity which is defined as a minimum De-bond depth of the soil in ASCE Standard 4 and 26.5ft no connectivity between structure and lateral soil over the upper half of the embedment. Last one is full no connection for only reference. The in-structure response spectra are compared with the response spectra without considering the embedment effect.

Nonlinear Soil–Foundation–Structure and Structure–Soil–Structure Interaction: Engineering Demands

2015 ◽  
Vol 141 (7) ◽  
pp. 04014177 ◽  
Author(s):  
Nicholas W. Trombetta ◽  
H. Benjamin Mason ◽  
Tara C. Hutchinson ◽  
Joshua D. Zupan ◽  
Jonathan D. Bray ◽  
...  
Keyword(s):  
Soil Structure ◽  
Soil Structure Interaction ◽  
Structure Interaction ◽  
Soil Foundation ◽  
Foundation Structure

Generalized dynamic Winkler model for nonlinear soil–structure interaction analysis

2008 ◽  
Vol 45 (4) ◽  
pp. 560-573 ◽  
Author(s):  
Nii Allotey ◽  
M. Hesham El Naggar
Keyword(s):  
Soil Structure ◽  
Interaction Analysis ◽  
Soil Structure Interaction ◽  
Winkler Foundation ◽  
Deep Foundations ◽  
Structure Interaction ◽  
Design Engineers ◽  
Winkler Model ◽  
Centrifuge Tests ◽  
Cyclic Degradation

The beam on nonlinear Winkler foundation (BNWF) model is widely used in soil–structure interaction (SSI) analysis owing to its relative simplicity. This paper focuses on the development of a versatile dynamic BNWF model for the analysis of shallow and deep foundations. The model is developed as a stand-alone module to be incorporated in commercial nonlinear structural analysis software. The features of the model discussed are the loading and unloading rules, slack zone development, the modeling of cyclic degradation and radiation damping. The model is shown to be capable of representing various response features observed in SSI experiments. In addition, the predictions of the model for centrifuge tests of piles in weakening and partially weakening soil are shown to be in good agreement with the experimental results. This agreement demonstrates the potential of the model as a useful tool for design engineers involved in seismic design, especially performance-based design.

Nonlinear Soil–Foundation–Structure and Structure–Soil–Structure Interaction: Centrifuge Test Observations

2014 ◽  
Vol 140 (5) ◽  
pp. 04013057 ◽  
Author(s):  
Nicholas W. Trombetta ◽  
H. Benjamin Mason ◽  
Tara C. Hutchinson ◽  
Joshua D. Zupan ◽  
Jonathan D. Bray ◽  
...  
Keyword(s):  
Soil Structure ◽  
Soil Structure Interaction ◽  
Centrifuge Test ◽  
Structure Interaction ◽  
Soil Foundation ◽  
Foundation Structure

Seismic response of sands in centrifuge tests

2008 ◽  
Vol 45 (4) ◽  
pp. 470-483 ◽  
Author(s):  
Mohammad H.T. Rayhani ◽  
M. Hesham El Naggar
Keyword(s):  
Shear Modulus ◽  
Seismic Response ◽  
Soil Structure ◽  
Site Response ◽  
Damping Ratio ◽  
Soil Structure Interaction ◽  
Response Analysis ◽  
Structure Interaction ◽  
Centrifuge Tests ◽  
Seismic Site Response

Seismic site response of sandy soils and seismic soil–structure interaction are investigated using an electrohydraulic earthquake simulator mounted on a centrifuge container at an 80g field. The results of testing uniform and layered loose to medium-dense sand models subjected to 13 simulated earthquakes on the centrifuge are presented. The variation of shear modulus and damping ratio with shear strain amplitude and confining pressure was evaluated and their effects on site response were assessed. The evaluated shear modulus and damping ratio agreed reasonably with laboratory tests and empirical relationships. Site response analysis using the measured shear wave velocity and estimated modulus reduction and damping ratio as input parameters produced good agreement with the measured site response. The effect of soil–structure interaction for structures situated on dry sand is also investigated. These tests have revealed many important insights with regard to the characteristics of seismic site response and seismic soil–structure behaviour. The tests showed that the seismic response of soil deposits, input motions, and overall behaviour of the structure are affected by soil stratification. The results showed that the seismic kinematic soil–structure interaction is not very significant for structures situated on loose sand.

scholarly journals Soil-structure interaction effects on modal parameters of office buildings with different number of stories

2018 ◽  
Vol 219 ◽  
pp. 03001 ◽  
Author(s):  
Natalia Lasowicz ◽  
Tomasz Falborski
Keyword(s):  
Soil Structure ◽  
Interaction Effects ◽  
Office Buildings ◽  
Soil Structure Interaction ◽  
Modal Parameters ◽  
Soil Conditions ◽  
Fundamental Vibration ◽  
Shear Moduli ◽  
Structure Interaction ◽  
Soil Foundation

The paper summarizes the results of a numerical investigation designed to study the soil-structure interaction effects on modal parameters of three office buildings. The reinforced-concrete 4-storey, 8-storey, and 12-storey office buildings, each with additional two levels of embedded basements, represent low, medium, and high-rise structures, respectively. In order to conduct this research, detailed finite-element structure models were prepared. Soil-foundation flexibility was represented with the use of spring-based solutions, incorporating foundation springs and dashpots. The influence of diverse soil conditions (represented by their average effective profile velocities and shear moduli) on the dynamic characteristics of the analyzed three office buildings (e.g. fundamental vibration periods) was investigated and discussed.

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