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http://dx.doi.org/10.7843/kgs.2022.38.7.49

Analysis of Reinforcement Effect of Hollow Modular Concrete Block on Sand by Laboratory Model Tests  

Lee, Chul-Hee (Dept. of Geotehcnical Engrg. Research, Korea Institute of Civil Engrg. and Building Technology)
Shin, Eun-Chul (Dept. of Civil and Environment Engrg., Incheon National Univ.)
Yang, Tae-Chul (Aceall co., Ltd.)
Publication Information
Journal of the Korean Geotechnical Society / v.38, no.7, 2022 , pp. 49-62 More about this Journal
Abstract
The hollow modular concrete block reinforced foundation method is one of the ground reinforcement foundation methods that uses hexagonal honeycomb-shaped concrete blocks with mixed crushed rock to reinforce soft grounds. It then forms an artificial layered ground that increases bearing capacity and reduces settlement. The hollow modular honeycomb-shaped concrete block is a geometrically economical, stable structure that distributes forces in a balanced way. However, the behavioral characteristics of hollow modular concrete block reinforced foundations are not yet fully understood. In this study, a bearing capacity test is performed to analyze the reinforcement effectiveness of the hollow modular concrete block through the laboratory model tests. From the load-settlement curve, punching shear failure occurs under the unfilled sand condition (A-1-N). However, the filled sand condition (A-1-F) shows a linear curve without yielding, confirming the reinforcement effect is three times higher than that of unreinforced ground. The bearing capacity equation is proposed for the parts that have contact pressure under concrete, vertical stress of hollow blocks, and the inner skin friction force from horizontal stress by confining effect based on the schematic diagram of confining effect inside a hollow modular concrete block. As a result of calculating the bearing capacity, the percentage of load distribution for contact force on the area of concrete is about 65%, vertical force on the area of hollow is 16.5% and inner skin friction force of area of the inner wall is about 18.5%. When the surcharge load is applied to the concrete part, the vertical stress occurs on the area of the hollow part by confining effect first. Then, in the filled sand in the hollow where the horizontal direction is constrained, the inner skin friction force occurs by the horizontal stress on the inner wall of the hollow modular concrete block. The inner skin friction force suppresses the punching of the concrete part and reduces contact pressure.
Keywords
Bearing capacity test; Confining effect; Hollow modular concrete block; Load distribution; Reinforcement effect;
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Times Cited By KSCI : 1  (Citation Analysis)
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1 Jeong, S.S. and Ko, J.Y. (2016), "Influence Factors on the Degree of Soil Plugging for Open-Ended Piles", Journal of the Korean Geotechnical Society, Vol.32, No.5, pp.27-36.   DOI
2 Kumar, J. and Madhusudhan, B. (2010), "Effect of Relative Density and Confining Pressure on Poisson Ratio from Bender and Extender Elements Tests", Geotechnique, Vol.60, No.7, pp.561-567.   DOI
3 Paikowsky, S.G. (1990), "The Mechanism of Pile Plugging in Sand", Proceedings of the 22nd Offshore Technology Conference, OTC 6490, 4, pp.593-604.
4 Yamahara, H. (1964), "Plugging Effects and Bearing Mechanism of Steel Pipe Piles", Transportation of the Architectural Institute of Japan, Vol.96, pp.28-35.   DOI
5 Kulhawy, F.H. (1983), "Transmission Line Structure Foundation for Uplift-Compression Loading", Report No. EL-2870, Electric Power Research Institute.
6 Bathurst, R.J. and Karpurapu, R. (1993), "Large Scale Triaxial Compression Testing of Geocell Reinforced Granular Soils", ASTM Geotechnical Testing Journal, Vol.16, No.3, pp.296-303.   DOI
7 Koerner, R.M. (1990), Designing with Geosynthetics, Prentice Hall.
8 Boussinesq, J. (1883), "Application des Potentials a L'Etude de L'Equilibre et du Mouvement des Solides Elastiques", Gauthier-Villars, Paris.
9 Das. B.M. (2008), Advanced Soil Mechanics, Taylor & Francis.
10 Jaky, J. (1944), "The Coefficient of Earth Pressure at Rest", Journal of the Society of Hungarian Architects and Engineering, Vol.78, No.22, pp.355-358.
11 Ko, J.Y. (2015), Evaluation of Bearing Capacity for Open-Ended Piles with Soil Plugging, Ph.D thesis, Yonsei University, Seoul.
12 Lee, K.C. (2002), A Study on the Bearing Capacity of Shallow Foundation Reinforced by Geocell, Ph.D Thesis, Kyunghee University, Seoul.
13 Paikowsky, S.G. (1989), A Static Evaluation of Soil Plug Behavior with Application to the Pile Plugging Problem, Ph.D thesis, Massachusetts Institute of Technology, Cambridge, MA.
14 Kulhawy, F.H. (1991), Drilled Shaft Foundation, Foundation Engineering Handbook, Van Nostrand Reinhold (Wiley).
15 Zhou, H. and Wen, X. (2008), "Model Studies on Geogrid- or Geocell-Reinforced Sand Cushion on Soft Soil", J. of Geotextiles and Geomembranes, Vol.26, Issue 3, pp.231-238.   DOI