Assessment of the compression characteristics and coefficient of lateral earth pressure of aggregate-expanded polystyrene beads composite fill-backfill using large oedometer experiments

2021 ◽  
Vol 302 ◽  
pp. 124145
Author(s):  
Shaghayegh Kazempour ◽  
Reza Jamshidi Chenari ◽  
Hadi Ahmadi ◽  
Meghdad Payan ◽  
Kostas Senetakis
2016 ◽  
Vol 846 ◽  
pp. 421-427
Author(s):  
Ahmed S. Alqarawi ◽  
Chin J. Leo ◽  
D.S. Liyanapathirana ◽  
Sanka Ekanayake

Integral Abutment Bridges are widely utilized around the world because they offer a design alternative minimizing the potential construction and maintenance difficulties associated with expansion joints in other types of bridges. However, integral bridge systems also have certain issues that result from the absence of expansion joints. This is because temperature changes induce cycles of elongations and shortenings in the bridge deck which lead to rotational movements in bridge abutments against and away from the retained soil. This phenomenon may develop long term problems in terms of settlement of the backfill at the bridge approach and escalation in the lateral earth pressure acting on the bridge abutments. This paper aims to investigate the approach settlement and lateral earth pressure development in integral bridges abutments using finite element modelling of a concrete bridge abutment and the adjoining soil using the ABAQUS software. The paper presents a parametric study of the effects imposed by abutment movements on the retained soil. This study also investigates the effectiveness of using expanded polystyrene (EPS) geofoam inclusions as a remedial measure to minimize the approach settlement and lateral stress ratcheting effects in Integral Abutment Bridges.


2021 ◽  
Vol 13 (9) ◽  
pp. 4754
Author(s):  
Muhammad Imran Khan ◽  
Mohamed A. Meguid

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.


Author(s):  
Xiaodong Zhao ◽  
Guoqing Zhou ◽  
Bo Wang ◽  
Wei Jiao ◽  
Jing Yu

Artificial frozen soils (AFS) have been used widely as temporary retaining walls in strata with soft and water-saturated soil deposits. After excavations, frozen soils thaw, and the lateral earth pressure penetrates through the soils subjected to freeze–thaw, and acts on man-made facilities. Therefore, it is important to investigate the lateral pressure (coefficient) responses of soils subjected to freeze–thaw to perform structure calculations and stability assessments of man-made facilities. A cubical testing apparatus was developed, and tests were performed on susceptible soils under conditions of freezing to a stable thermal gradient and then thawing with a uniform temperature (Fnonuni–Tuni). The experimental results indicated a lack of notable anisotropy for the maximum lateral preconsolidated pressures induced by the specimen’s compaction and freeze–thaw. However, the freeze–thaw led to a decrement of lateral earth pressure coefficient  K0, and  K0 decrement under the horizontal Fnonuni–Tuni was greater than that under the vertical Fnonuni–Tuni. The measured  K0 for normally consolidated and over-consolidated soil specimens exhibited anisotropic characteristics under the vertical Fnonuni–Tuni and horizontal Fnonuni–Tuni treatments. The anisotropies of  K0 under the horizontal Fnonuni–Tuni were greater than that under the vertical Fnonuni–Tuni, and the anisotropies were more noticeable in the unloading path than that in the loading path. These observations have potential significances to the economical and practical design of permanent retaining walls in soft and water-saturated soil deposits.


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