• Title/Summary/Keyword: Lateral earth pressure

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Evaluation of Ultimate Lateral Resistance for Single Pile Using Strain Wedge Model in Sand (모래지반에서 쐐기모델을 이용한 단말뚝의 극한수평저항력 산정)

  • Kim, Ji-Seong;Kang, Gi-Chun
    • Journal of the Korean Geotechnical Society
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    • v.32 no.12
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    • pp.15-22
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    • 2016
  • The magnitude of the lateral resistance that resists the lateral movement of the pile is controlled by the amount of the pile movement and the strength and stiffness of soil. In this paper, we proposed an equation which produces the ultimate lateral resistance of the laterally loaded single pile in sand using the strain wedge model of the soil deformation. The ultimate lateral resistance in strain wedge model is composed of earth pressure of wedge rear, the shear resistance on the side of the wedge, and the frictional resistance between pile and ground. The ultimate lateral resistance determined by the proposed equation was compared with the Ashour, F.D.M., field test in sand. As a result, the error of the proposed equation and Ashour theory, field test, F.D.M were respectively 1.03%, 0.40~3.32%, 6.02%.

A Study on Effect of Earth Pressure Reduction and the Silo Earth Pressure of the Retaining Wall by CLSM Backfill with Waste Foundry Sand (폐주물사를 이용한 유동성 채움재의 절토구간 옹벽 뒤채움시 사일로토압 및 토압경감효과 연구)

  • Cho, Jae-Yun;Lee, Kwan-Ho;Cho, Yoon-Ho
    • International Journal of Highway Engineering
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    • v.4 no.2 s.12
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    • pp.19-31
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    • 2002
  • The recycling of waste foundry sand(WFS) and fly ash as by-products of industry is one of the urgent problem to deal with. For the recycling of these materials, CLSM(controlled low strength materials) concept was adopted. This research has been done for last three years. In this research, couple of selected waste foundry sand and fly ash were used as fine aggregate. Also, WFS modified by Proper chemical liquid was used for the comparison. The main focus is to evaluate the silo earth pressure and the reduction effect due to the use of CLSM instead of normal fine aggregate. Silo effect, which occurs at short distance between retaining wall and backfill, was not detected because the characterization of CLSM is highly different from that of normal aggregate. Therefore, the theory for earth pressure, like Rankine theory or Coulomb theory, should be carefully used for CLSM. The reduction of earth pressure for modified WFS is higher than the others. But, the final earth pressure is converged at very small value, even though the reduction effect depends on the curing time.

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Passive p-y curves for rigid basement walls supporting granular soils

  • Imad, Elchiti;George, Saad;Shadi S., Najjar
    • Geomechanics and Engineering
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    • v.32 no.3
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    • pp.335-346
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    • 2023
  • For structures with underground basement walls, the soil-structure-interaction between the side soil and the walls affects the response of the system. There is interest in quantifying the relationship between the lateral earth pressure and the wall displacement using p-y curves. To date, passive p-y curves in available limited studies were assumed elastic-perfectly plastic. In reality, the relationship between earth pressure and wall displacement is complex. This paper focuses on studying the development of passive p-y curves behind rigid walls supporting granular soils. The study aims at identifying the different components of the passive p-y relationship and proposing a rigorous non-linear p-y model in place of simplified elastic-plastic models. The results of the study show that (1) the p-y relationship that models the stress-displacement response behind a rigid basement wall is highly non-linear, (2) passive p-y curves are affected by the height of the wall, relative density, and depth below the ground surface, and (3) passive p-y curves can be expressed using a truncated hyperbolic model that is defined by a limit state passive pressure that is determined using available logarithmic spiral methods and an initial slope that is expressed using a depth-dependent soil stiffness model.

Evaluation of Lateral Deformation and Vertical Stress of Geosynthetics Reinforced Walls by the Scale Model Test (축소모형실험을 통한 토목섬유 보강토옹벽의 수평변위 및 수직응력 평가)

  • Cho, Sam-Deok;Lee, Kwang-Wu;You, Seung-Kyong
    • Journal of the Korean Geosynthetics Society
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    • v.16 no.4
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    • pp.119-127
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    • 2017
  • This paper presents a study of reinforced earth model wall reinforced by geosynthetics subjected to vertical surcharge. 7 types of reinforced earth model wall were constructed in the model box($100cm{\times}140cm{\times}100cm$) to assess the deformation and stress behavior of model walls according to different tensile strength and laying number of reinforcement and surcharge pressures. 3 types of geosynthetics that have different tensile strength were used as reinforcement. The test was carried out by changing the number of reinforcement to 5, 7, 9, and surcharge pressure to 50, 100, 150, 200, 250 kPa. The model test found that the maximum lateral displacements occurred at the 0.7 H (H : Wall height) position from the bottom of the model wall and vertical stress was low in the smaller surcharge pressure and the larger tensile strength of reinforcement.

Analysis of the non-supported excavation scrummed by truss tower (무지보 흙막이 트러스 구조물의 안정성 검토)

  • Joo, Yong-Sun;Cho, Sung-Keun;Kim, Nak-Kyung;Kim, Young-Suk;Kim, Ju-Hyung
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.1317-1323
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    • 2009
  • A finite element analysis was performed for new earth retention system that is a kind of truss tower with non-supported excavation. A 2D finite element model was adopted in this study to investigate the behavior of the earth retention system. Just because this non-supported truss tower system is too complex to model in 2D plain-strain condition to itself, so have to simplify it by the conception of equivalent rigidity. The horizontal displacement of the wall and lateral earth pressure distribution on the wall were computed. And it is compared with NAVFAC design manual.

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An Experimental Study on the Stability of Assembled Earth Retaining Wall in Sandy Ground (사질토 지반에 설치된 조립식 지주옹벽(AER)의 안정성에 관한 실험적 연구)

  • Yoo, Jae-Won;Im, Jong-Chul;Hwang, Sung-Pil;Kim, Chang-Young;Choi, Jung-Hyun;Kim, Hong-Sun
    • Journal of the Korean Geotechnical Society
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    • v.32 no.2
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    • pp.43-52
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    • 2016
  • Assembled Earth Retaining wall (AER-wall is used here) using back pile (back supporting beam is used from here) has been developed at Pusan National University. Both cost and time have been significantly reduced because AER-wall can be fabricated in a shop. Also its stability has been improved with a back supporting beam reducing earth pressure. In this study, the test results were analyzed after laboratory model tests were performed. The lateral displacement of AER-wall significantly decreased with both inclined wall and back supporting beams. As a result, the stability of AER-wall and effect of back supporting beam have been analyzed and verified.

A Basic Analysis of Behavior of Rectangular Prestressed Pilecolumn I (사각 프리스트레스트 말뚝형 기둥 기초적 특성 사례 연구 I)

  • Chon, Kyungsu;Kim, Nagyoung;Chung, Kyuchung
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.12
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    • pp.13-22
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    • 2013
  • A substructure of bridges is very important structural element for safety and supporting not only vertical loads as dead load and live load but lateral loads as break load, wind load, seismic load, hydrostatic pressure and dynamic water pressure, lateral earth pressure, impulsive load, temperature change and load effect of temperature change, creep and shrinkage. Most of domestic bridges are reinforced concrete piers and have an effect on economy of bridge. Recently, understanding importance of substructure, we are getting more interested in new substructure system.

Calculation of Reasonable Equivalent Uniform Pressure Height and Lateral Earth Pressure Characteristics of Retaining Structures (옹벽에 작용하는 수평토압 특성 분석 및 합리적인 등가상재하중 높이 산정)

  • Lee, Kicheol;Chung, Moon-Kyung;Seo, Seunghwan;Kim, Dongwook
    • Journal of the Korean Geosynthetics Society
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    • v.18 no.4
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    • pp.139-149
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    • 2019
  • For retaining wall designs, horizontal earth pressure induced by traffic loads over the walls is calculated based on equivalent uniform pressure height. The AASHTO LRFD design standards propose equivalent uniform pressure height of traffic loads; however, the equivalent uniform pressure height is calibrated using the US standard trucks. As the domestic standard trucks are different from the US standard trucks, in this study, new domestic equivalent uniform pressure height is proposed using the Boussinesq theory varying vehicle directions, Poisson's ratios of pavement layers, and retaining wall height. The proposed equivalent uniform pressure heights are generally higher than those proposed by the AASHTO design standards because the axle loads and their densities of two domestic standard trucks are higher than those of the US standard trucks. The most highest equivalent uniform pressure height was found for traffic direction perpendicular to longitudinal direction of retaining wall.

Centrifuge modeling of dynamically penetrating anchors in sand and clay

  • An, Xiaoyu;Wang, Fei;Liang, Chao;Liu, Run
    • Geomechanics and Engineering
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    • v.30 no.6
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    • pp.539-549
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    • 2022
  • Accidental anchor drop can cause disturbances to seabed materials and pose significant threats to the safety and serviceability of submarine structures such as pipelines. In this study, a series of anchor drop tests was carried out to investigate the penetration mechanism of a Hall anchor in sand and clay. A special anchor drop apparatus was designed to model the inflight drop of a Hall anchor. Results indicate that Coriolis acceleration was the primary cause of large horizontal offsets in sand, and earth gravity had negligible impact on the lateral movement of dropped anchors. The indued final horizontal offset was shown to increase with the elevated drop height of an anchor, and the existence of water can slow down the landing velocity of an anchor. It is also observed that water conditions had a significant effect on the influence zone caused by anchors. The vertical influence depth was over 5 m, and the influence radius was more than 3 m if the anchor had a drop height of 25 m in dry sand. In comparison, the vertical influence depth and radius reduced to less than 3 m and 2 m, respectively, when the anchor was released from 10 m height and fell into the seabed with a water depth of 15 m. It is also found that the dynamically penetrating anchors could significantly influence the earth pressure in clay. There is a non-linear increase in the measured penetration depth with kinematic energy, and the resulted maximum earth pressure increased dramatically with an increase in kinematic energy. Results from centrifuge model tests in this study provide useful insights into the penetration mechanism of a dropped anchor, which provides valuable data for design and planning of future submarine structures.

Numerical study on the connection type of inner-slab in double deck tunnel (복층터널 내부슬래브의 연결형식에 관한 수치해석적 연구)

  • Lee, Ho-Seong;Moon, Hyun-Koo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.18 no.5
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    • pp.441-451
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    • 2016
  • This study analyzed behavior of the segment lining considering connection type between inner-slab and segment lining for a double deck tunnel by Shield TBM. In order to establish the design requirements of inner-slab and segment lining in double deck tunnel, inner structure of double deck tunnel at each purpose was analyzed and compared connection type between inner-slab and segment lining. And analyses have been carried out through the beam-spring model by MIDAS Civil 2012. As a result of this study, inner-slab, connection type of between inner-slab and segment lining and Lateral earth pressure coefficients were analyzed to verify the significant design factors.