• Geotechnical Engineering
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• v.9 no.1
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• pp.69-78
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• 1993

The Coulomb and Rankine theories have been usually used for design of retaining walls, in which the earth pressures have been assumed as a triangular distribution For the rigid retaining w리1 with inclined bacuace and horizontal surface backfilled by cohesionless soils, the analytical method of earth pressure distribution has been newly suggested by using the concept of the flat arch. The active thrust obtained by this method agrees well with those by the existing theories, except the Rankine solution. The analyzed results show that the height to the center of pressure depends mainly on the inclination of the back wall and the wall friction, instead of 0.33H, where H is the wall height.

• Journal of the Korean GEO-environmental Society
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• v.13 no.11
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• pp.5-10
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• 2012

Many electric poles in the softground have been collapsed due to external load. In this study, several tests were performed with variation of numbers and depths of anchor blocks to find effects of anchor blocks on stability of concrete electric poles through earth pressure and displacement analysis. 1.50m depth of anchor block seems appropriate among three kinds of depths. The 2.25m depth of anchor block makes larger displacement due to disturbance caused by excessive excavation. The deeper anchor block, the less earth pressure of passive zone, an active earth pressure gets larger. When two anchor blocks were installed, displacement at top pole decreased 43.8% and 55.6% at ground when 1 anchor block was installed.

• Journal of the Korean Geotechnical Society
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• v.30 no.4
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• pp.47-63
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• 2014

In this study theories of earth pressure such as Rankine, Coulomb, Trial Wedge, Improved Trial Wedge, used in the design for onshore and offshore structures, are analyzed and the characteristics of loaded pressure to virtual back (wall, plane) and wall surface in accordance with the structure type are suggested. To investigate characteristics of earth pressure, gravity retaining wall with inclined angle and cantilever wall with inclined ground are movilized for onshore structures and caisson and block type quay wall are mobilized for offshore structures. Based on various theories, the earth pressure applied angle(wall friction angle) and sliding angle toward the wall, which is influenced by the heel length, are calculated and compared. In the case of long heel, the pressure by Rankine's method in virtual plane and the mobilized angle are most reasonably estimated by the ground slope, and in the case of short heel, the pressure by Coulomb's method and the mobilized angle by the angle of wall friction. In addition, the sliding angle toward the wall estimated by the improved trial wedge method is large than the value of Rankine's method. Finally, in this study the reasonable method for calculating the pressure and the mobilized angle that can be applied to the routine design of port structures is proposed. The proposed method can decide the earth pressure with length of a heel and a self weight of retaining wall according to sliding angle toward the wall.

• Geotechnical Engineering
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• v.13 no.5
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• pp.19-34
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• 1997

Classical earth pressure theories normally assume that ground condition remains uniform for considerable distance from the wall, and that the movement of the wall is enough to result in the development of an active pressure distribution. In the case of many low gravity walls in cut, constructed, for example, by using gabions or cribs, this is not commonly the case. In strong ground a steep temporary face will be excavated for reasons of economy, and a thin wedge of backfill will be placed behind the wall following its construetion. A designer then has the difficulty of selecting appropriate soil parameters and a reasonable method of calculating the earth pressure on the w리1. This paper starts by reviewing the existing solutions applicable to such geometry. A new silo and a wedge methods are developed for static and dynamic cases, and the results obtained from these are compared with two experimental results which more correctly mod el the geometry and strength of the wall, the fill, and the soil condition. Conclusions are drawn concerning both the magnitute and distribution of earth pressures to be supported by such walls.

• Geomechanics and Engineering
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• v.36 no.3
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• pp.217-229
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• 2024

Determining lateral earth pressure coefficient (EPC) K is a classic problem in geotechnical engineering. It is a key parameter for estimating the stresses in backfilled openings. For backfilled openings with rigid and immobile walls, some suggested using the Jaky's at-rest earth pressure coefficient K₀ while other suggested taking the Rankine's active earth pressure coefficient K_a. A single value was proposed for the entire backfilled opening. To better understand the distributions of stresses and K in a backfilled opening, a series of laboratory tests have been conducted. The horizontal and vertical normal stresses at the center and near the wall of the opening were measured. The values of K at the center and near the wall were then calculated with the measured horizontal and vertical normal stresses. The results show that the values of K are close to K_a at the center and close to K₀ near the wall. Furthermore, the experimental results show that the horizontal stress is almost the same at the center and near the wall, indicating a uniform distribution from the center to the wall. It can be estimated by analytical solutions using either K_a or K₀. The vertical stress is higher near the center than near the wall. Its analytical estimation can only be done by using K_a at the center and K₀ near the wall. Finally, the test results were used to calibrate a numerical model of FLAC2D, which was then used to analyze the influence of column size on the stresses and K in the backfilled opening.

• Journal of the Speleological Society of Korea
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• no.65
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• pp.31-37
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• 2004

Karst water was defined as 'Water which fills the cavities of the earth continuously and is only subject to gravity and hydraulic pressure.' Karst springs are water outlets from karst-hydrologically active cavities in water-soluble rocks, whether they are on the surface or within the earth. Karst springs behave so differently that the general principles of classification for all springs can be applied to them with a few exceptions. Firstly, classification according to the outflow: perennial springs, periodic springs, rhythemically springs, episodically flowing spring. Secondly, classification according to geologic and tectonic conditions: bedding springs, fracture springs, overflow spring, ascending spring.

• Geotechnical Engineering
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• v.12 no.4
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• pp.75-86
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• 1996

Current methods to estimate the earth pressure for retaining wall analysis are based on Rankine or Coulomb approaches, in which the soil mass behind wall is assumed to reach to failure state with sufficient lateral movements. Some of recent research works carried out by field measurements reveal that the active earth. pressures by Ranking or Coulomb method are underestimated. It means that the lateral movements of wall and soil would not be mobilized enough to reach the failure state. In this study, the finite element method with Drucker -Prager model for soil is employed to investigate the behavior of concrete cantile,tier retaining wall, together with the influence of inclined backfill. The results indicate that the earth pressures on the retaining wall are strongly related to the mobilized lateral movements of wall and soil and that Ranking and Coulomb methods underestimate the resultant earth pressures and the increasing effect on earth pressure by inclined backfill. Based on this study, a simplified method to determine to earth pressures on cantilever retaining wall with horizontal backfill is proposed.

• Geotechnical Engineering
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• v.1 no.1
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• pp.21-30
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• 1985

The reasonable static and dynamic earth pressure equations were developed by applying the Dubrova's theory and Chang's method to the following cases of wall movements; (1) Active case rotating about the top (2) Active case rotating about the bottom (3) Passive case rotating about the top (4) Passive case rotating about the bottom The equations are presented in accordance with particular wall displacements for the sand and cohesive back-fill, respectively. The results computed by the proposed equations are compared with the conventional theoretical values.

• Geotechnical Engineering
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• v.8 no.4
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• pp.81-98
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• 1992

Deep excavation increases utility of underground spaces for high buildings. subways etc. To excavate vertically the underground, safe earth retaining walls and supporting systems should be prepared. Recently anchors have been used to support the excavation wall. The anchored excavation has some advantages toprovide working space for underground construction. In this paper the prestressed anchor loads were measured by load cells which attacted to the anchors to support the excavation walls at eight construction fields. where under-ground deep excavation was performed on cohesionless soils. The lateral pressures on the retaining walls, which are estimated from the measured anchor forces, shows a trapezoidal distribution that the pressure increases linearly with depth from the ground surface to 30% of the excavation depth and then keeps constant value regardless of the stiffness of the walls. The maximum lateral pressure was same to 63% of the Ranking active earth pressure or 17% of the vertical overburden pressure at the final depth The investigation of the measured lateral pressure on the anchored excavation walls shows that empirical earth pressure diagram presented by Terzaghi-Peck and Tschebotarioff could be applied with some modifications to determine anchor loads for the anchored excavation in cohesionless soils.

• Journal of the Korean Geotechnical Society
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• v.20 no.6
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• pp.127-136
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• 2004

The soil arching in the backfill, which affects the magnitude and distribution of active earth pressure on a retaining wall, has also an effect on the stability and cross-sectional area of the retaining wall. In this study, results obtained from Paik's equation that includes arching effect on active earth pressure are compared with those from Coulomb theory to investigate the influence of the soil arching on active earth pressure, overturning moment, stability and cross-sectional area of translating rigid retaining walls. The comparisons show that the active forces including arching effects are always higher than those from Coulomb theory, irrespective of $\phi$ and $\delta$ values. The overturning moments, shear force and moment on the rigid wall are also higher when considering arching effects than when not considering arching effects. The deviation of shear forces and moments by including and excluding arching effects becomes maximum at the height of 0.02-0.08 times wall height from the base of the wall. Therefore, if a translating rigid retaining walls is designed based on Coulomb theory, the wall may reach sliding and overturning failures due to arching effect in the backfill and the cross-sectional area of the wall, especially at lower part of the wall, may not be sufficient to resist to shear force and moment.