Preliminary numerical study on the reduction of seismic pounding damage to buildings with expanded polystyrene blocks

Abstract This paper presents a novel buckling-restrained brace (BRB) where the inner core is restrained by a concrete infilled Expanded Polystyrene Sheet (EPS) instead of the conventional concrete infilled tube section, to resist inner core buckling. It serves two purposes, firstly, the EPS is a ductile material, which is favourable in terms of seismic performance and, secondly, the outer construction material has better corrosion resistance. Thus, the life of the steel core can be prolonged. In this study, 6 BRB specimens were prepared, of which 3 BRB specimens were infilled with concrete and the remaining 3 BRB specimens with concrete and EPSs, in order to study their performance under cyclic loading. Three different core heights, all with the same core thickness, were adopted. The test results indicate that the load-carrying capacity of this novel BRB is higher than the conventional BRB. Further, the length of the steel tube also affects the strength of the seismic disaster mitigation system. Lastly, a numerical study on a single bay RC frame, with and without BRB subjected to time history analysis, was conducted to check the global performance of this novel system. It was found that the structural responses had substantially decreased.

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

Canadian Geotechnical Journal ◽

10.1139/t08-128 ◽

2009 ◽

Vol 46 (3) ◽

pp. 318-338 ◽

Cited By ~ 40

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.

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Experimental and numerical study of composite lightweight structural insulated panel with expanded polystyrene core against windborne debris impacts

Materials & Design (1980-2015) ◽

10.1016/j.matdes.2014.04.038 ◽

2014 ◽

Vol 60 ◽

pp. 409-423 ◽

Cited By ~ 36

Author(s):

Wensu Chen ◽

Hong Hao

Keyword(s):

Numerical Study ◽

Expanded Polystyrene ◽

Windborne Debris

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

Sustainability ◽

10.3390/su13094754 ◽

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.

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

Geosciences ◽

10.3390/geosciences9100448 ◽

2019 ◽

Vol 9 (10) ◽

pp. 448 ◽

Cited By ~ 3

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.

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The Numerical and Experimental Investigation of the Change of the Thermal Conductivity of Expanded Polystyrene at Different Temperatures and Densities

International Journal of Polymer Science ◽

10.1155/2019/6350326 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9

Author(s):

Battal Doğan ◽

Hüsamettin Tan

Keyword(s):

Thermal Conductivity ◽

Numerical Study ◽

Expanded Polystyrene ◽

Insulation Materials ◽

Numerical Studies ◽

Different Temperatures ◽

Three Stages ◽

Structure Geometry ◽

C 30

The determination of the thermal conductivity of insulation materials depending on which parameters in the application as well as the production is very important. In this direction, the parameters affecting thermal conductivity should be determined to improve the efficiency of the insulation materials. It is also a fact that expanded polystyrene blocks have different thermal conductivities at the same density value depending on the production process. In this study, it was determined, experimentally and numerically, that the thermal conductivity of expanded polystyrene material at different densities is dependent on which parameters and changes in temperature. Expanded polystyrene materials consist of blocks of 30×30 cm with density of 16, 21, and 25 kg/m3 and a thickness of 20 mm. Thermal conductivity measurements were performed in FOX 314 (Laser Comp., USA) operating in accordance with ISO 8301 and EN 12667 standards. The measurements were made for expanded polystyrene blocks at the average temperatures of 10°C, 20°C, 30°C, and 40°C. The numerical study has three stages as the acquisition of electron microscope images (SEM) of expanded polystyrene blocks, modeling of internal structure geometry with CAD program, and realization of solutions with a finite element-based ANSYS program. Findings from experimental and numerical studies and the parameters affecting thermal conductivity were determined. Finally, it is thought that numerical methods can be used to obtain a preliminary idea for EPS material in determining thermal conductivity by comparing the findings of experimental and numerical studies.

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Effects of Geofoam Panels on Static Behavior of Cantilever Retaining Wall

Advances in Civil Engineering ◽

10.1155/2018/2942689 ◽

2018 ◽

Vol 2018 ◽

pp. 1-16 ◽

Cited By ~ 1

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.

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