• Title/Summary/Keyword: Lateral soil 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%.

The Measurement Method of Lateral Displacement in Bridge Abutment. (교량구조물의 측방이동 측정방법에 관한 연구)

  • 장용채
    • Journal of Korean Port Research
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    • v.14 no.1
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    • pp.115-124
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    • 2000
  • This study is a suggest a measurement method of lateral displacement, which can be used to judge the stability of bridge abutment on soil undergoing lateral movement. The abutment of bridge on soft foundation makes lateral movement due to the settlement of back fill and lateral flow. To measure the displacement of such a abutment, there are a lot of indirect method for measurement such as survey of leveling or inclinometer gauge around the abutment. But all of them are not sufficient to confirm the ground behavior and measure the exact lateral behavior of structure. As making the structure and pile cooperatively by measuring the movement of lateral displacement, for measuring the abutment displacement precisely by using the inclinometer. In this work, we try to suggest efficient measuring method of abutment displacement and its application.

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Numerical FEM assessment of soil-pile system in liquefiable soil under earthquake loading including soil-pile interaction

  • Ebadi-Jamkhaneh, Mehdi;Homaioon-Ebrahimi, Amir;Kontoni, Denise-Penelope N.;Shokri-Amiri, Maedeh
    • Geomechanics and Engineering
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    • v.27 no.5
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    • pp.465-479
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    • 2021
  • One of the important causes of building and infrastructure failure, such as bridges on pile foundations, is the placement of the piles in liquefiable soil that can become unstable under seismic loads. Therefore, the overarching aim of this study is to investigate the seismic behavior of a soil-pile system in liquefiable soil using three-dimensional numerical FEM analysis, including soil-pile interaction. Effective parameters on concrete pile response, involving the pile diameter, pile length, soil type, and base acceleration, were considered in the framework of finite element non-linear dynamic analysis. The constitutive model of soil was considered as elasto-plastic kinematic-isotropic hardening. First, the finite element model was verified by comparing the variations on the pile response with the measured data from the centrifuge tests, and there was a strong agreement between the numerical and experimental results. Totally 64 non-linear time-history analyses were conducted, and the responses were investigated in terms of the lateral displacement of the pile, the effect of the base acceleration in the pile behavior, the bending moment distribution in the pile body, and the pore pressure. The numerical analysis results demonstrated that the relationship between the pile lateral displacement and the maximum base acceleration is non-linear. Furthermore, increasing the pile diameter results in an increase in the passive pressure of the soil. Also, piles with small and big diameters are subjected to yielding under bending and shear states, respectively. It is concluded that an effective stress-based ground response analysis should be conducted when there is a liquefaction condition in order to determine the maximum bending moment and shear force generated within the pile.

The Lateral Earth Pressure Distribution of the Earth Retaining Structure Installed in Colluvial Soil (붕적토에 설치된 흙막이구조물의 측방토압분포)

  • Hong, Won-Pyo;Yea, Geu-Guwen
    • The Journal of Engineering Geology
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    • v.18 no.4
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    • pp.433-437
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    • 2008
  • It's essential to build an earth retaining structure at the beginning and end point of a tunnel constructed in a colluvium area. A large scale of colluvial soil may cause a problem to the stability of the excavation ground. An excavation in colluvium has different behavior characteristics from those in a sandy soil due to unstable elements and needs counter measures for it. There are few systematic research efforts on the behavior characteristics of an earth retaining structure installed in colluvial soil. Thus this study set out to collect measuring data from an excavation site at the tunnel pit mouth in colluvium and set quantitative criteria for the safety of an earth retaining structure. After comparing and analyzing the theoretical and empirical earth pressure from the measuring data, the lateral earth pressure distribution acted on the earth retaining wall was suggested.

Stability Analysis of LNG Storage Tank with Ground Freezing (LNG 저장탱크의 기초 지반 동결시 안정성에 대한 평가)

  • Shin, Eun-Chul;Kim, Soo-Wan;Park, Jung-Jun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.1218-1231
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    • 2008
  • Recently the energy dependence of LNG resource is being increased. So the enlargement of LNG storage is constructed in the coastal area. Most of LNG tanks are constructed below the ground level, and thus the hydraulic uplift pressure could be a problem against the weight of tank structure. Specifically, the settlement of foundation soil in the LNG tank is also important in the aspect of safety. The low temperature around LNG tank is induced the ground freezing and hence increasing the soil volume and earth pressure. The additional lateral earth pressure due to ground freezing could be applied to the LNG tank. In this study, the stability of LNG storage tank was evaluated with consideration of freezing earth pressure by using computer program TEMP-W.

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Laboratory Test and Field Study of Soft Ground Improvement Effect by Using Various PVDs (실내실험과 현장실험을 통한 다양한 PVD의 연약지반개량효과)

  • Shin, Eun-Chul;Nazarova, Zhanara
    • Journal of the Korean Geosynthetics Society
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    • v.7 no.2
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    • pp.15-21
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    • 2008
  • The advantages of prefabricated vertical drains over conventional sand drains include their relatively low costs, less disturbance to the soil mass, the easinees of installation, and their flexibility which ensures the integrity of the drains during installation. This study tested the change of discharge capacities with respect to the hydraulic gradients for each lateral pressure. From the test results, as increases the overburden pressure, the clay soil is being consolidated, and also lateral pressure to the PVD specimen is increased. Therefore, the discharge capacity is decreased. The size of opening space in the core of PVDs is proportionally related to the discharge capacity. The numerical analysis was performed with utilizing computer simulation with considering field conditions. The results of numerical analysis are compared well with the field measurements.

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A Study on the WFS Co-mixtures by Small Scale Retaining Wall Test (모형옹벽실험을 이용한 폐주물사 혼합재의 지반공학 적용성 연구)

  • 조재윤;이관호;이인모
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.03b
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    • pp.419-426
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    • 2000
  • The purpose of this study is to present the application of WFS co-mixtures for retaining wall as flowable backfill. The fly ash, generated at the Tae-An thermoelectric power plant, was used in this research and was classified as Class F. Green Sand, Furane Sand, and Coated Sand, which had been used at a foundry located in Pusan, were used. Couple of laboratory tests and small scale retaining wall tests were performed to obtain the physical properties of the WFS co-mixtures and the possibility of backfill materials of retaining wall. The range of permeability for all the co-mixtures was from 3.0${\times}$10$\^$-3/ cm/s to 6.0${\times}$10$\^$-5/ cm/s. The unconfined strength of the 28-day cured specimens reached around 550kPa. Results of the consolidated-undrained triaxial test showed that the internal friction angle is between 33.5$^{\circ}$ and 41.8$^{\circ}$. The lateral earth pressure against wall decreased up to 80% of initial pressure within a 12 hours and the total lateral earth pressure is less than that of typical granular soil. It was enough to construct the backfill for the standard retaining of 6m with just two steps, like fill the co-mixtures for half of retaining wall, and then fill the others after 1 day. The stability of retaining wall for overturning and sliding increased as the curing time elapsed.

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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.

Study on Application of Criteria of Lateral Flow in Soft Soils (측방유동 판정기준의 적용성 연구)

  • Chae, Young-Soo;Moon, Han-Joong;Kim, Dae-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.2
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    • pp.219-223
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    • 2006
  • In this paper, the criteria of the lateral displacement in soft soil due to embankment were evaluated. The lateral displacement was measured at a pier structure in a new harbor construction site, and the measurement was compared with the criteria. The results by the measurement such as the critical pressure causing lateral movement in terms of undrained strength, the lateral movement index by Japan Highway Co., the lateral displacement index by Japan Construction Ministry, the modified index by Korean Highway Co. were estimated to be lower than the respective index values.

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Long term earth pressure behavior behind stub abutment (난쟁이 교대배면의 장기 토압거동)

  • 박영호;정경자;김낙영;황영철
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.779-786
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    • 2002
  • To find a long term horizontal movement of superstructure caused by seasonal thermal change, several types of gages are installed such as soil earth pressuremeter behind stub abutment and jointmeter between approach slab and relief slab. As results, maximum passive earth pressure behind integral bridge abutments centerline with lateral movement of superstructure is about 1/6 of classic Rankine's earth pressure. And its distribution is not triangular but rectangular shape due to shape behind integral bridge abutments.

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