Numerical parametric study of expanded polystyrene (EPS) geofoam seismic buffers

2009 ◽  
Vol 46 (3) ◽  
pp. 318-338 ◽  
Author(s):  
Saman Zarnani ◽  
Richard J. Bathurst
Keyword(s):  
Numerical Study ◽  
Retaining Wall ◽  
Expanded Polystyrene ◽  
Buffer System ◽  
Predominant Frequency ◽  
Eps Geofoam ◽  
Wall Structures ◽  
Earthquake Record ◽  
Numerical Parametric Study ◽  
Parameter Values

Expanded polystyrene (EPS) geofoam seismic buffers can be used to reduce earthquake-induced loads acting on rigid retaining wall structures. A numerical study was carried out to investigate the influence of wall height; EPS geofoam type, thickness, and stiffness; and excitation record on seismic buffer performance. The numerical simulations were carried out using a verified FLAC code. The influence of parameter values was examined by computing the maximum forces on the walls, the buffer compressive strains, and the relative efficiency of the buffer system. In general, the closer the predominant frequency of excitation to the fundamental frequency of the wall model, the greater the seismic loads and buffer compression. The choice of earthquake record is shown to affect the magnitude of maximum earth force and isolation efficiency. However, when the wall response for walls 3 to 9 m in height are presented in this study in terms of isolation efficiency, the data from scaled accelerograms and matching harmonic records with the same predominant frequency fall within a relatively narrow band when plotted against relative buffer thickness. For the range of parameters investigated, a buffer stiffness value less than 50 MN/m3 was judged to be the practical range for the design of these systems.

scholarly journals Evaluating the Role of Geofoam Properties in Reducing Lateral Loads on Retaining Walls: A Numerical Study

2021 ◽  
Vol 13 (9) ◽  
pp. 4754
Author(s):  
Muhammad Imran Khan ◽  
Mohamed A. Meguid
Keyword(s):  
Numerical Study ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Retaining Walls ◽  
Expanded Polystyrene ◽  
Wall Structure ◽  
Eps Geofoam ◽  
Lateral Earth Pressure ◽  
Backfill Soil

Expanded polystyrene (EPS) geofoam is a lightweight compressible material that has been widely used in various civil engineering projects. One interesting application of EPS in geotechnical engineering is to reduce the lateral earth pressure on rigid non-yielding retaining walls. The compressible nature of the EPS geofoam allows for the shear strength of the backfill soil to be mobilized, which leads to a reduction in lateral earth pressure acting on the wall. In this study, a finite element model is developed and used to investigate the role of geofoam inclusion between a rigid retaining wall and the backfill material on the earth pressure transferred to the wall structure. The developed model was first calibrated using experimental data. Then, a parametric study was conducted to investigate the effect of EPS geofoam density, relative thickness with respect to the wall height, and the frictional angle of backfill soil on the effectiveness of this technique in reducing lateral earth pressure. Results showed that low-density EPS geofoam inclusion provides the best performance, particularly when coupled with backfill of low friction angle. The proposed modeling approach has shown to be efficient in solving this class of problems and can be used to model similar soil-geofoam-structure interaction problems.

scholarly journals Effects of Geofoam Panels on Static Behavior of Cantilever Retaining Wall

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Navid Hasanpouri Notash ◽  
Rouzbeh Dabiri
Keyword(s):  
Numerical Study ◽  
Retaining Wall ◽  
Retaining Walls ◽  
Expanded Polystyrene ◽  
Buffer System ◽  
Static Behavior ◽  
Static Loads ◽  
Static Performance ◽  
Cantilever Retaining Walls ◽  
Better Than

Geofoam is one of the geosynthetic products that can be used in geotechnical applications. According to researches, expanded polystyrene (EPS) geofoam placed directly against a rigid retaining wall has been proposed as a strategy to reduce static loads on the wall. This study employed a finite difference analysis using a 2-D FLAC computer program by considering yielding and nonyielding states for retaining walls to explore the effectiveness of geofoam panels in improving the static performance of cantilever retaining walls. Retaining walls at heights of 3, 6, and 9 meters and geofoam panels with densities of 15, 20, and 25 (kg/m3) at three relative thicknesses of t/H = 0.05, 0.2, and 0.4 were modelled in this numerical study. In addition, the performance of the double EPS buffer system, which involves two vertical geofoam panels, in retaining walls’ stability with four panel spacing (50, 100, 150, and 200 cm) was also evaluated in this research. The results showed that use of EPS15 with density equal to 15 (kg/m3) which has the lowest density among other geofoam panels has a significant role in reduction of lateral stresses, although the performance of geofoam in nonyielding retaining walls is better than yielding retaining walls.

scholarly journals Use of Compressible Expanded Polystyrene Blocks and Geogrids for Retaining Wall Structures

2002 ◽  
Vol 42 (4) ◽  
pp. 29-41 ◽  
Author(s):  
Yoshimichi Tsukamoto ◽  
Kenji Ishihara ◽  
Hirohito Kon ◽  
Takayuki Masuo
Keyword(s):  
Retaining Wall ◽  
Expanded Polystyrene ◽  
Wall Structures

scholarly journals Numerical Analysis of Earthquake Load Mitigation on Rigid Retaining Walls Using EPS Geofoam

2012 ◽  
Vol 6 (1) ◽  
pp. 21-25 ◽  
Author(s):  
Deling Wang ◽  
Richard J. Bathurst
Keyword(s):  
Numerical Simulations ◽  
Retaining Wall ◽  
Expanded Polystyrene ◽  
Numerical Results ◽  
Shaking Table ◽  
Great Promise ◽  
Finite Element Program ◽  
Physical Test ◽  
Eps Geofoam ◽  
Element Program

The mitigation of seismic-induced dynamic earth forces by placing a vertical layer of expanded polystyrene (EPS) geofoam buffer between a rigid retaining wall and the backfill soil is a recent geotechnical innovation. In this paper, the influence of an EPS geofoam buffer on the reduction of dynamic wall forces is numerically studied by simulating the results of three reduced-scale models of rigid walls mounted on a large shaking table. Numerical simulations were carried out using the finite element program ABAQUS. The paper shows that the numerical results capture the trend in earth forces with increasing base acceleration for all three models. The quantitative dynamic load-time response from the numerical simulations was also judged to be in good agreement with measured physical test values. The numerical trend of EPS geofoam also is the same as that of measured test data. With the increasing time, the compression of EPS geofoam increases. And softer EPS geofoam produces more compression which takes more vibration energy by its deformation. The numerical results confirm the results of physical tests that demonstrate that EPS geofoam seismic buffers hold great promise to reduce earthquake-induced dynamic loads against rigid retaining wall structures.

scholarly journals Application of EPS Geofoam to a Soil–Steel Bridge to Reduce Seismic Excitations

Geosciences ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 448 ◽  
Author(s):  
Tomasz Maleska ◽  
Joanna Nowacka ◽  
Damian Beben
Keyword(s):  
Numerical Study ◽  
Expanded Polystyrene ◽  
Steel Bridges ◽  
Steel Bridge ◽  
The Finite Element Method ◽  
Seismic Excitations ◽  
Eps Geofoam ◽  
Mining Areas ◽  
Natural Earthquakes ◽  
Wave Induced

There have only been a limited number of analyses of soil–steel bridges under seismic and anthropogenic (rockburst) excitations. Rockbursts are phenomena similar to low-intensity natural earthquakes. They can be observed in Poland (Upper and Lower Silesia) as well as in many parts of the world where coal and gas are mined. The influence of rockbursts and natural earthquakes on soil–steel bridges should be investigated because the ground motions caused by these two kinds of excitations differ. In the present paper, a non-linear analysis of a soil–steel bridge was carried out. Expanded polystyrene (EPS) geofoam blocks were used in a numerical model of the soil–steel bridge to buffer the seismic wave induced by a rockburst (coming from a coal mine) as well as a natural earthquake (El Centro record). The analyzed soil–steel bridge had two closed pipe arches in its cross-section. The span of the shells was 4.40 m and the height of the shells was 2.80 m. The numerical analysis was conducted using the DIANA program based on the finite element method (FEM). The paper presents the FEM results of a 3D numerical study of a soil–steel bridge both with and without the application of the EPS geofoam under seismic excitations. The obtained results can be interesting to bridge engineers and scientists dealing with the design and analysis of bridges situated in seismic and mining areas.

Numerical Analysis on Vibration Mitigation Effect of EPS Geofoam on Retaining Wall

2010 ◽  
Vol 168-170 ◽  
pp. 1038-1041
Author(s):  
De Ling Wang
Keyword(s):  
Retaining Wall ◽  
Expanded Polystyrene ◽  
Shaking Table ◽  
Finite Element Program ◽  
Physical Test ◽  
Eps Geofoam ◽  
Backfill Soil ◽  
Scale Models ◽  
Element Program ◽  
Rigid Walls

The mitigation of earth force by placing expanded polystyrene (EPS) geofoam buffer between retaining wall and backfill soil under dynamic loading is a topic worth consideration. In this paper, the effects of EPS geofoam buffer on the reduction of thrust wall force are numerically studied to simulate three reduced-scale models of rigid walls using a large shaking table. Numerical simulation technique using the finite element program Abaqus is described. The paper shows that the numerical Abaqus models are able to capture the trend in earth forces with increasing base acceleration for all three models. The use of the EPS geofoam as a compressible buffer yields obviously reduction of the lateral seismic thrust against retaining wall. The quantitative dynamic load–time response of the numerical simulations was in good agreement with measured physical test values.

Expanded Polystyrene (EPS) Geofoam Unit Cells with Fly Ash

2016 ◽  
Author(s):  
A. H. Padade ◽  
S. Dutta ◽  
M. B. Nadaf ◽  
B. Ram Rathan Lal ◽  
J. N. Mandal
Keyword(s):  
Fly Ash ◽  
Expanded Polystyrene ◽  
Eps Geofoam ◽  
Unit Cells

A Numerical Study of Single Phase Dielectric Fluid Immersion Cooling of Multichip Modules

2012 ◽  
Vol 2012 (1) ◽  
pp. 000581-000590
Author(s):  
Roy W. Knight ◽  
Seth Fincher ◽  
Sushil H. Bhavnani ◽  
Daniel K. Harris ◽  
R. Wayne Johnson
Keyword(s):  
Single Phase ◽  
Printed Circuit Board ◽  
Numerical Study ◽  
Design Guidelines ◽  
Circuit Board ◽  
Dielectric Fluid ◽  
Multichip Modules ◽  
Ansys Fluent ◽  
Immersion Cooling ◽  
Numerical Parametric Study

Immersion, single phase free convection cooling of multichip modules on a printed circuit board in a pool of dielectric fluid was examined numerically, with experimental verification of baseline cases. A multi-chip module with multiple thermal test cells with temperature sensing capability was simulated. The commercially available computational fluid dynamics program from ANSYS, Fluent, was used with the electronics packaging front end, Icepak, employed to create the models and compact conduction modules. Simulations were first performed of an experimental test vehicle which had five 18 mm by 18 mm die, arranged in a cross pattern, equally spaced die, 25 mm between them. Two of the die were aligned vertically with the center die, two aligned horizontally with it. The board was suspended vertically in a large pool of dielectric fluid. Heat was dissipated in the die at a flux of up to 2 W/cm2, based on the die surface area. Simulation results were compared with experimentally measured die temperature values and excellent agreement was seen for the cases of one die heated and all five die uniformly heated with the board cooled by FC-72. A numerical parametric study was performed to examine the effect of die size and spacing on temperature rise. In addition to FC-72, immersion cooling in Novec 649 and HFE 7100 were modeled. Design guidelines are suggested for dielectric fluid immersion cooled multichip modules.

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