• Earthquakes and Structures
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• v.24 no.3
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• pp.155-163
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• 2023

The purpose of this paper is to investigate the coupled effect of SSI and pounding on dynamic responses of unequal height adjacent buildings with insufficiently separation distance subjected to seismic loading. Numerical investigations were conducted to evaluate effect of the pounding coupling SSI on a Reinforced Concrete Frame Structure system constructed on different soil fields. Adjacent buildings with unequal height, including a 9-storey and a 3-storey reinforced concrete structure, were considered in numerical studies. Pounding force response, time-history and root-mean-square (RMS) of displacement and acceleration with different types of soil and separations were presented. The numerical results indicate that insufficient separation could lead to collisions and generate severe pounding force which could result in acceleration and displacement amplifications. SSI has significant influence of the seismic response of the structures, and higher pounding force were induced by floors with stiffer soil. SSI is reasonable neglected for a structure with a dense soil foundation, whereas SSI should be taken into consideration for dynamic analysis, especially for soft soil base.

• Journal of the Korean Geotechnical Society
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• v.18 no.4
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• pp.7-19
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• 2002

This paper presents the results of an investigation on the effect of foundation stiffness on the performance of soil-reinforced segmental retaining walls (SRWalls). Laboratory model tests were performed using a reduced-scale physical model to capture the fundamentals of the manner in which the foundation stiffness affects the behavior of SRWalls. A series of finite-element analyses were additionally performed on a prototype wall in order to supplement the findings from the model tests and to examine full-scale behavior of SRWalls encountered in the field. The results of the present investigation indicate that lateral wall displacements significantly increase with the decrease of the foundation stiffness. Also revealed is that the increase in wall displacements is likely to be caused by the rigid body movement of the reinforced soil mass with negligible internal deformation within the reinforced soil mass. The findings from this study support the current design approaches, in which the problem concerning the foundation condition are treated in the frame work of the external stability rather than the internal stability. The implications of the findings from this study to current design approaches are discussed in detail.

• Journal of the Korean Geosynthetics Society
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• v.7 no.1
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• pp.1-6
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• 2008

In this study, the deformation and strength characteristics for non-woven geotextile-reinforced decomposed granite soil on the triaxial compression test under the same condition as the underground. The specimen of reinforced earth was made of the decomposed granite soil imbedded horizontal in a given space with non-woven geotextile. Four different type of specimen was used in this experimental programme; UR for unreinforced, R-1 for a single non-woven geotextile sheet, R-2 for two sheets, and R-3 for three sheets. According to the testing results, it was found that the strength of the reinforced soil increased when the non-woven geotextile sheets were more used. These results would be applied to the design of reinforced earth structure through the theoretical interpretation method.

• Geomechanics and Engineering
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• v.6 no.2
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• pp.195-211
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• 2014

Stone columns (or granular column) have been used to increase the load carrying capacity and accelerating consolidation of soft soil. Recently, the geosynthetic reinforced stone column technique has been developed to improve the load carrying capacity of the stone column. In addition, reinforcement prevents the lateral squeezing of stone in to surrounding soft soil, helps in easy formation of stone column, preserve frictional properties of aggregate and drainage function of the stone column. This paper investigates the improvement of load carrying capacity of isolated ordinary and geotextile reinforced sand column through field load tests. Tests were performed with different reinforcement stiffness, diameter of sand column and reinforcement length. The results of field load test indicated an improved load carrying capacity of geotextile reinforced sand column over ordinary sand column. The increase in load carrying capacity depends upon the sand column diameter, stiffness of reinforcement and reinforcement length. Also, the partial reinforcement length about two to four time's sand column diameter from the top of the column was found to significant effect on the performance of sand column.

• Geomechanics and Engineering
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• v.38 no.3
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• pp.261-273
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• 2024

This study presents a groundbreaking analytical approach to find an exact solution for the bearing capacity of strip footings on reinforced slopes, utilizing the two-phase approach and slip line method. The two-phase approach is considered as a generalized homogenization technique. The slip line method is leveraged to derive the stress field as a lower bound solution and the velocity field as an upper bound solution, thereby facilitating the attainment of an exact solution. The key finding points out the variation of the bearing capacity factor N_γ with influencing factors including the backfill soil friction angle, the footing setback distance from the slope crest edge, slope angle, strength, and volumetric fraction of inclusion layers. The results are evaluated by comparing them with those of relevant studies in the literature considering analytical and experimental studies. Through the application of the two-phase approach, it becomes feasible to determine the tensile loads mobilized along the inclusion layers associated with the failure zone. It is attempted to demonstrate the results by utilizing non-dimensional graphs to clearly illustrate variable impacts on reinforced soil stability. This research contributes significantly to advancing geotechnical engineering practices, specifically in the realm of static design considerations for reinforced soil structures.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.3
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• pp.23-30
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• 2002

In recently, using of steel reinforcements by reinforcing materials of the reinforced earth, micro-pile and root-pile etc,. is wide-spreading in the stabilizing control of cutting and embankment slopes, but the failure mechanism of reinforced earth as well as the effect of insert angles or types of reinforcement and others are not defined clearly. In this study, therefore heavy-duty direct shear tests were exercised on the reinforced soil and the non-reinforced soil, which was executed for research on the interaction of soil-reinforcement and theirs behavior. The hardness and softness and the standard sands were used for modeling of reinforced soil, the material constants for the computer simulation were estimated from the results of CD-Test. The effects of reinforcing and of friction increasing on the softness, area ratio of reinforcements is equal, were the better than them of the hardness, as well the reinforcing effects of shear strength without regard to the area ratio is much the same at $10^{\circ}$, insert angle of reinforced bar, differ from them of the existing study. Then, the results of numerical analysis showed that the behavior of reinforcements displayed bending resistance and shear resistance at $15^{\circ}$ and $30^{\circ}$, respectively. Also, the state of strain transfer was observed and the behavior of resistance mechanism on reinforcements presented almost the same them of landslides stabilizing pile.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.404-409
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• 2005

The reinforced concrete blocks for reinforced earth layer are combined with soil structures consisted of facing unit, reinforcing materials and soil. Those environmentally friendly facing units of reinforced concrete blocks are made of mine waste and tailing and that will be played a role of the effects of recycling use of wasted resources. The block are consisted of three types as curved or straight in order to control topography. The systems are also not limited to wall hight so that they are effectively used for protecting the slope of banking and cutting of earth works. The reinforced concrete blocks developed this time will be effectively applied for not only retaining wall, road, park, golf course, public office building constructions but also protecting of slope stabilization projects.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.3
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• pp.69-78
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• 2003

The main purpose of this study was to verify the shore margin protection effect of the root system of Salix gracilistyla Miq. developed from direct sticking cuttings on wetland, focusing on the effect of the root system reducing soil particle dissociation rate in water. The soil dissociation rate was examined through slaking tests with cylindric pure soil column at maximum particle density and the same size column of root reinforced soil. The dry weight of remained soil was measured after 5, 10, 15, 30minutes and 1, 6, 12, 24, 48hours inundation. As results, the soil particles began to dissociate severely at 10 minutes and only 10% of soil particles were left after 25minutes inundation. The stable slope angle of pure soil was $36^{\circ}$after 24 hours. On the other hand, the columns of root reinforced soil were stable even after 24hours, being dissociated only 7.2% of soil particles. So, it was revealed that the root system was very effective materials protecting more than 80% of soil particle from dissociation in inundation.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.681-688
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• 2005

The Green Wall is the highest eco-system among a segmental retaining wall systems. Recently, the demand of high segmental retaining wall (SRW) is increased in domestic. The soil nailing system is applied in order to maintain the high SRW stability for steeper slope. However, the proper design approach that can consider the earth pressure reduction effects in soil nailing system has not been proposed. Hence, the purpose of this study was to provide the design and analysis technique of the segmental retaining wall reinforced by soil nailing. Also, in this study, various parametric studies using numerical method as shear strength reduction (SSR) technique were carried out. In the parametric study, the length ratio and the bond ratio of the soil nailing were changed to identify the earth pressure reduction effect of the retaining wall reinforced by soil nailing.

• Journal of the Korean Geosynthetics Society
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• v.8 no.1
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• pp.33-40
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• 2009

The laboratory tests and field plate load test were carried out to evaluate the reinforcement effect of geocell for road construction. The geocell-reinforced subgrade shows the increment of cohesion and friction angle with comparison of non-reinforced subgrade. In addition, the field plate load test was performed on the geocell-reinforced subgrade to estimate the bearing capacity of soil. The direct shear test was conducted with utilizing a large-scale shear box to evaluate the internal soil friction angle with geocell reinforcement. The number of cells in the geocell system is varied to investigate the effect of soil reinforcement. The theoretical bearing capacity of subgrade soil with and without geocell reinforcement was estimated by using the soil internal friction angle. The field plate load tests were also conducted to estimate the bearing capacity with geocell reinforcement. It is found out that the bearing capacity of geocell-reinforced subgrade gives 2 times higher value than that of unreinforced subgrade soil. The settlement and the distribution of deformation were also estimated by using the finite element method. The magnitude of settlements on the geocell-reinforced subgrade and unreinforced subgrade are 6.8cm and 1.2cm, respectively.