• Title/Summary/Keyword: Lateral slope

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Limit Velocity for Lateral Stable Bed in Natural Curved Channels (자연하천 만곡부의 횡방향 안정하상을 위한 한계속도)

  • Choe, Jong-In
    • Journal of Korea Water Resources Association
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    • v.35 no.2
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    • pp.195-201
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    • 2002
  • In this study, an equation is proposed to estimate the limit velocity for lateral stable bed in a curved channel stream. The stable bed on lateral direction is satisfied when there is no more deformation occurs on the transverse bed slope and non-scouring condition in a bend. A theoretical equation for limit velocity is derived using a transverse bed slope model. So, the limit velocity has its theoretical background in the equilibrium of two forces, lateral shear force at the bed due to longitudinal flow and the corresponding lateral bed shear force. To verify the equation, data from four natural river channels were used. There is good agreement between the calculated values using this equation and the measured values. The corrections in equation was found to be correlated with the averaged particle Froude number.

A Study on the Lateral Earthpressure at Behind Structure for Backfill by Sand (구조물 배면에 사질토 되메움시 유발되는 수평토압에 관한연구)

  • Lee, Sang-Duk;Kang, Se-Gu
    • Journal of the Korean Geosynthetics Society
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    • v.10 no.4
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    • pp.11-18
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    • 2011
  • In this study, the reinforcing effect of geogrids in the narrow backfill by sand was experimentally studied. In the model tests, the size of space and the slope of the cut off slope were varied out. The resultant and the distribution of lateral earth pressure were measured. Width of backfill space varied 10 cm, 20 cm, 30 cm at the lower wall level and angle of the cut off slope varied $90^{\circ}$, $75^{\circ}$, $60^{\circ}$. Geogrids were installed in the backfill. Measured results showed that the distribution of the lateral earth pressure due to the narrow backfill developed in a arching shape. And the earth pressure was reduced due to the reinforcement of the backfill by geogrid. geogrid helps reduction of lateral earth pressure.

A Study on Lateral Movement of Bridge Abutment on Soft Ground (연약지반상 교대의 측방이동에 관한 연구)

  • 홍원표;한중근
    • Geotechnical Engineering
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    • v.10 no.4
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    • pp.53-66
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    • 1994
  • In case of using pile foundation to support bridge abutments on soft ground, the soft ground often causes serious troubles such as lateral movement of the bridge abutments. The foundation piles in soil undergoing lateral movement is one of the typical passive piles. However, Generally, on design of the piles for abutments, the piles have not been considered as a passive piles; sofar:. Because it is difficult to assess the effect of the lateral movement on the desigin and reasonable design method is not established yet. In this study, several abutments, of which lateral movement was taken place, was investigated. Based on the investigation a criterion was presented to assess the lateral movement of the soft soil under backfill for abutment. By use of the criterion, the lateral movement of abutment could be predicted. As the results of thin study, it was anon that the lateral movement of abutment could be occured when the safety factor of slope stability is lese than either 1.5(without the pile effect) or 1.8 (with the pile effect). Especially, excessive lateral movements were occurred when the safety factor of slope stability is less than either 1.0(without the pile effect) or 1.1 (with the pile effect).

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Finite Element Analysis for the Effects on the Stiffness of the Embankment and Sandmat on the Deformation Property and the Safety of Road Embankment (성토체 및 모래매트의 강성이 하부지반의 변형과 성토체의 안전에 미치는 영향에 대한 유한요소해석)

  • Bae, Woo-Seok;Kim, Jong-Woo;Kwon, Young-Cheul
    • Journal of the Korean Society of Safety
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    • v.22 no.4
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    • pp.57-65
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    • 2007
  • Effects on the stiffness of the embankment and sandmat on the construction safety of road embankment was investigated in this study by the numerical experiments using FEM. Two points was mainly focused in this study especially. First the deformation characteristics by the change of the stiffness of sand mat and embankment was investigated by the analyzing the consolidation settlement at the center of the embankment and the lateral displacement at the toe of the embankment. And, the effect of the stiffness on the stress distribution characteristics was also investigated in this study. Furthermore, slope stability analysis was carried out to gain the safe factor by change the stiffness of the sandmat and the embankment. The objective of the study is supplying the result of the numerical experiments for the geotechnical engineers who use the FEM for the safety design of the soil structures. As a result, the stiffness of the superstructures greatly affects on the deformation characteristics both in consolidation settlement and lateral displacement. However, it can be aware that it is not dominants to the stress distribution in the aspect that the no changes in the residual excess pore water pressure. Therefore, the decision of the stiffness has to be carried out deliberately considering not only the consolidation the magnitude of the settlement and the lateral displacement, but the slope stability.

A field investigation on an expansive soil slope supported by a sheet-pile retaining structure

  • Zhen Zhang;Yu-Liang Lin;Hong-Ri Zhang;Bin He;Guo-Lin Yang;Yong-Fu Xu
    • Structural Engineering and Mechanics
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    • v.91 no.3
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    • pp.315-324
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    • 2024
  • An expansive soil in 4970 special railway line in Dangyang City, China, has encountered a series of landslides due to the expansion characteristics of expansive soil over the past 50 years. Thereafter, a sheet-pile retaining structure was adopted to fortify the expansive soil slope after a comprehensive discussion. In order to evaluate the efficacy of engineering measure of sheet-pile retaining structure, the field test was carried out to investigate the lateral pressure and pile bending moment subjected to construction and service conditions, and the local daily rainfall was also recorded. It took more than 500 days to carry out the field investigation, and the general change laws of lateral pressure and pile bending moment versus local daily rainfall were obtained. The results show that the effect of rainfall on the moisture content of backfill behind the wall decreases with depth. The performance of sheet-pile retaining structure is sensitive to the intensity of rainfall. The arching effect is reduced significantly by employing a series of sheet behind piles. The lateral pressure behind the sheet exhibits a single-peak distribution. The turning point of the horizontal swelling pressure distribution is correlated with the self-weight pressure distribution of soil and the variation of soil moisture content. The measured pile bending moment is approximately 44% of the ultimate pile capacity, which indicates that the sheet-pile retaining structure is in a stable service condition with enough safety reserve.

A Relative Study on Safe Factor by Different Analyses of Slope Stability (EPS공법에 의한 측방유동 저감효과에 관한 해석적 연구)

  • An, Joon-Hee;Jang, Jeong-Wook;Park, Choon-Sik
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.1181-1186
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    • 2006
  • This study analyzed the reductive effect of lateral flow by the section and height of reinforcement of EPS. The conclusions of the study are as follows. (1) The lateral flow increased as the section of reinforcement decreased. The reinforcement section that satisfied the allowable range of the lateral flow turned out to beapproximately 80% of the standard reinforcement section. (2) As reinforcement height was decreasing, the lateral flow increased. The reinforcement heigh that satisfied the allowable range of the lateral flow turned out to be approximately 50% of the total lateral height of abutment.

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Deformation Behavior and Slope Stability Effect of Anchored Retention Walls Installed in Cut Slope (절개사면에 설치된 앵커지지 합벽의 변형거동 및 사면안정효과)

  • Hong Won-Pyo;Han Jung-Geun
    • Journal of the Korean Geotechnical Society
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    • v.20 no.9
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    • pp.57-64
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    • 2004
  • In order to establish the design method of anchored retention walls in cut slope, the behavior of anchored retention walls and backside ground needs to be investigated and checked in detail. In this study, the behavior of anchored retention walls was investigated by instrumentation installed in cut slope for an apartment construction site stabilized by a row of piles and anchored retention walls. When the anchor was installed at each excavating stages, the horizontal deflection of retention wall decreased, while the horizontal deformation of backside ground increased. The deflection of anchored retention wall decreased as the anchor was prestressed. The prestressed anchor farce has a great effect on the deflection of retention walls, while it has little effect on the deformation of its backside ground. The maximum horizontal deflection of anchored retention walls was developed between $1\%\;and\;4\%$ of excavation depth, which are $2\~8$ times larger than max. horizontal deflection of anchored retention walls including rock layers with backside horizontal ground. Meanwhile, SLOPILE (ver. 3.0) program analyzes the slope stability effects for anchored retention walls. As a result of analysis on slope stability analysis, the lateral earth pressure applied at anchored retention piles could be used as the mean values of empirical lateral pressures using anchored retention wall with horizontal ground at its backside.

A STUDY OF THE POSTERIOR SLOPE OF THE ARTICULAR EMINENCE IN PATIENTS WITH INTERNAL DERANGEMENT (악관절 내장증환자에서 관절돌기의 후방경사에 관한 연구)

  • Lee Geon-Ill;You Dong-Soo
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.21 no.2
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    • pp.225-234
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    • 1991
  • This study was designed to investigate the effects of the posterior slope of the articular eminence and the condylar angulation to the posterior slope of the articular eminence on internal derangement of TMJ. The materials consisted of 78 transcranial oblique lateral projections of 31 normal subjects and 47 internal derangement patients. The results were as follows: 1. The posterior slope of the articular eminences in normal group were larger than that in abnormal group, but there were not significant differences between each group about the condylar angulation to the posterior slope of the articular eminences. 2. The differences between in the right and left sides in patients who were affected unilaterally and bilaterally were larger than that in normal groups. 3, In patients affected unilaterally, there were not significant differences between affected joints and unaffected joints about the posterior slope of the articular eminence and the condylar angulation to the posterior slope of the articular eminence. 4. In abnormal group, there were significant differences between each group about condylar angulation to the post, slope of the articular eminence (ant. disk displacement without reduction > fibrous adhesion > ant. disk displacement with reduction), but not about the post, slope of the articular eminence.

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Lateral long term behavior for web direction of Driven H-Piles in Embankment (성토지반에 타입된 H 말뚝의 약축방향에 대한 횡방향 장기지지거동)

  • 박영호;정경자;김낙영;황영철
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.06a
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    • pp.43-56
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    • 2002
  • To find a lateral long term behavior of driven H-piles in embankment, inclinometer is installed at pile and measurement is done during a year. When behavior of measured slope angles is in accord with behavior of nonlinear p-y curves(Reese, Murchison and O'Neil, Matlock's p-y analysis), maximum displacement of pile head, maximum stress and maximum bending moment of pile obtained from the numerical analysis are shown. As results, maximum lateral displacement at pile head, maximum stress and maximum bending moment of pile are shown linear behavior, And maximum lateral load, maximum lateral displacement, and maximum bending moment at pile obtained from the numerical analysis are 8∼12.4tonf, 9∼10.1㎜, and 10.39∼12.67tonf-m per pile according to the curves, respectively.

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A Study on the Change of Heat Transmission Coefficient According to the Degree of Windows Slope (창의 경사도에 따른 열관류율 변화에 관한 연구)

  • 황하진;이경희
    • Journal of the Korean housing association
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    • v.12 no.3
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    • pp.133-140
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    • 2001
  • This study investigated the heat transmission coefficient through the experiment that the skylight, slope window of 60 degree and 30 degree consisted of pair glass and the double window of external window and internal window paper were suitable for heat insulation. As the result of experiment, the heat transmission coefficient of slope window was 1.06 times in the 60 degree, 1.18 times in the 30 degree and 1.31 times in the skylight as a standard lateral window. The heat transmission coefficient in the double window of external window and internal window paper was 3.017$\textrm{㎉}$/$\textrm{m}^2$.hr.$^{\cire}C$. The slope window was not suitable for the prescription by the increase of the heat transmission coefficient, so the user must pay attention to the treatment. This study investigated only the slope window of 12mm and 16mm pair glass and the double window of external window and internal window paper, study on the various pattern of window must be achived in a future.

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