• Title/Summary/Keyword: pile movement

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Scaled Test on the Behavior of the Toe of Drilled Shaft on Rock Mass (암반에 근입된 말뚝의 선단 거동 특성에 관한 축소모형시험 연구)

  • Park, Woan-Suh;Choi, Se-Keun;Jeon, Seok-Won;Han, Yong-Hee
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.1166-1171
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    • 2008
  • Despite of the increasing number of the application of drilled shaft piles in construction site, most studies on pile capacity have been focused on the side shear resistance. But it is common that the drilled shaft is socketed on the rock so as to use its bearing resistance. The prediction of the end movement and characteristics of the bearing capacity of the pile is great important as well. Therefore, a series of scaled model tests were carried out in order to study the characteristics of the bearing capacity on rock mass. The material of the test block was cement mortar which was mixed with sand, cement and water, and the size of a test block size was $240{\times}240{\times}240mm$. The axial load was applied by a miniaturized pile of 45mm in diameter and flat jacks and steel plate were used for confinement to simulate the real underground loading conditions. The relation of load-displacement was measured in various different conditions of rock mass such as strength, discontinuity of the rock mass and in-situ stress, so q-w curves of the end of the pile were presented for each condition.

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REINFORCING EFFECTS OF MICRO-PILES (억지말뚝의 억제효과)

  • Jung, Sung-Yun;Chang, Ki-Tae;Han, Heui-Soo
    • Journal of the Korean Geophysical Society
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    • v.7 no.4
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    • pp.305-311
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    • 2004
  • Several sensor systems are used to estimate the reinforceing effect of pile in hihg cut slopes, and to find a failure zone in slopes effectively. Inclinometer, extensometer and V/W sensor have shown a great potentiality to serve real time health monitoring of the slope structures. They were embedded or attached to the structures, we conducted field tests and test results have shown great solutions for sensor systems of Civil Engineering Smart Structures. This research is to seek for the relationships among the slope movement and the reinforceing effect of pile, and the strain distribution in a active zone by analyzing the data from the in-situ measurement so that the possible failure zone should be well defined based on the relationships. Also, the relationships between temperature and reinforceing effect of pile, and the strain distribution are estimated in this paper.

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Characteristics of Bearing Capacity for SCP Composite Ground reinforced by the Sheet piles Restraining Deformation (변위억제형 Sheet pile 설치에 따른 SCP복합지반의 지지력 특성)

  • Park, Byung-Soo
    • Journal of Navigation and Port Research
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    • v.30 no.8 s.114
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    • pp.711-719
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    • 2006
  • A series of geotechnical centrifuge model tests and numerical modelling have been performed to study engineering characteristics of the composite ground reinforced by both the Sand Compaction Piles(SCPs) and the deformation-reducing sheet piles. The research has covered several key issues such as the load-settlement relation, the stress concentration ratio and the final water content of the ground Totally three centrifuge tests have been conducted by changing configuration of the sheet piles, i.e., a test without the sheet pile, a test with the sheet pile at a single side and a test with the sheet piles at the both sides. In the model tests, a vertical load was applied in-flight on the ground surface. On the other hand, class-C type numerical modelling has been performed by using the SAGE-CRISP to compare the centrifuge test results using an elasto-plastic model for SCPs and the Modified Cam Clay model for the soft clay. It has been found that the sheet piles can restraint failure of foundation, thereby increasing yield stress of the ground. The stress concentration ratio was in the range of $2{\sim}4$. In addition, numerical analysis results showed reductions both in the ground heave($20{\sim}30%$) and in the horizontal movement($28{\sim}43%$), demonstrating the deformation-reducing effect of the sheet piles.

Integral Bridge Using H-pile (H-말뚝을 이용한 일체식교대 교량)

  • 정경자;김성환;유성근
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.03a
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    • pp.241-248
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    • 1999
  • The existing bridge with deck joint has many problems during construction and maintenance. To overcome these difficulties, an integral bridge, which is defined as the practice of constructing bridges without deck joints, is proposed in this study. A test bridge with 3 spans of PC beam was selected to verify the function of the bridge and is under construction. Characteristics of integral bridge are followings: $\circled1$ Flexible H-piles under the abutment are installed to accommodate thermal movements of the superstructures of bridge. $\circled2$ PC beam of the superstructure and the abutment are integrated. $\circled3$ The existing approach and relief slabs are applied to minimize the stress transfer occurred from the bridge deck to the pavement. $\circled4$ A cyclic control joint is installed between approach and relief slabs to absorb the thermal movement. $\circled5$ It is used a dual direction bearing which is cheaper than single direction bearing and has a good workability as well. It is also installed a shear block on the top of pier coping to protect the lateral movement caused by temperature change and earthquake.

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A study on the stability of pile bridge abutment on soft ground undergoing lateral flow (연약지반에서의 말뚝기초 교대의 측방유동 대책공법 적용에 관한 연구)

  • 오일록;채영수
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.753-760
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    • 2003
  • An existing studies concern about movement of pile bridge abutments. However, lateral displacement cause the serious failure of bridge by embankment under soft soil lateral flow A intention is obtained by analyzing the relationship between the safety factor of evaluation for lateral movements. Precise investigation and analysis are performed, in which the lateral movement of bridge abutments has occurred, and construct design strut-slab between bridge abutments in order to restraint lateral flow. As a result of this study, it was found that when evaluation for lateral movements is allowed to use Tschebotarioff's method and lateral flow decision number (I) and revision lateral flow decision number (M$_{I}$) by Korea Highway Corporation. Most important thing is decision of pressure of lateral flow at this case. Tschebotarioff's isoscales triangle method have no trouble analysis of pressure of lateral flow. Strut-slab method are nearly not have constructed case in this field site study that applied method. The method are between abutments combined steel strut and reinforced concrete slab. This method are effective restraint lateral flow but have little difficulty if long span bridge between abutments.s.

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A Comparative Study on Construction Method for a Large Underground Station under Pile Supported Bridge (모형실험을 이용한 교량하부 통과 구간 굴착공법 비교 연구)

  • Yoo, Chung-Sik;Chung, Eun-Mok
    • Journal of the Korean Geosynthetics Society
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    • v.16 no.4
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    • pp.177-190
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    • 2017
  • This paper presents the results of an experimental study on the effect of large underground station construction method under an existing pile supported bridge using reduced-scale model tests. A series of tests were conducted on design alternatives using 1g models for different design options for which tunnel structures were created considering the similitude law. Deformation fields obtained using the PIV analysis and LVDTs together with strains in tunnel structures were used to investigate the effect of the construction methods on the pile supported bridge. The results of the tests demonstrated that the pipe roof structure is more efficient in limiting the ground deformation as well as the settlement of bridge foundation than a 2-Arch tunnel. It is also shown that the PIV analysis can be effectively used in analyzing ground tunneling induced ground movement for cases in which a construction sequence governs ground movement.

A parametric study of settlement and load transfer mechanism of piled raft due to adjacent excavation using 3D finite element analysis

  • Karira, Hemu;Kumar, Aneel;Hussain Ali, Tauha;Mangnejo, Dildar Ali;Mangi, Naeem
    • Geomechanics and Engineering
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    • v.30 no.2
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    • pp.169-185
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    • 2022
  • The urbanization and increasing rate of population demands effective means of transportation system (basement and tunnels) as well as high-rise building (resting on piled foundation) for accommodation. Therefore, it unavoidable to construct basements (i.e., excavation) nearby piled foundation. Since the basement excavation inevitably induces soil movement and stress changes in the ground, it may cause differential settlements to nearby piled raft foundation. To understand settlement and load transfer mechanism in the piled raft due to excavation-induced stress release, numerical parametric studies are carried out in this study. The effects of excavation depths (i.e., formation level) relative to piled raft were investigated by simulating the excavation near the pile shaft (i.e., He/Lp=0.67), next to (He/Lp=1.00) and below the pile toe (He/Lp=1.33). In addition, effects of sand density and raft fixity condition were investigated. The computed results have revealed that the induced settlement, tilting, pile lateral movement and load transfer mechanism in the piled raft depends upon the embedded depth of the diaphragm wall. Additional settlement of the piled raft due to excavation can be account for apparent loss of load carrying capacity of the piled raft (ALPC). The highest apparent loss of piled raft capacity ALPC (on the account of induced piled raft settlement) of 50% was calculated in in case of He/Lp = 1.33. Furthermore, the induced settlement decreased with increasing the relative density from 30% to 90%. On the contrary, the tilting of the raft increases in denser ground. The larger bending moment and lateral force was induced at the piled heads in fixed and pinned raft condition.

Estimation of the Depth of Embedded Sheet Piles Using Two Types of Geophysical Loggings (다종 물리검층을 통한 시트파일 근입 심도 추정 연구)

  • Hwang, Sungpil;Kim, Wooseok;Jeoung, Jaehyeung;Kim, Kiju;Park, Byungsuk;Lee, Chulhee
    • The Journal of Engineering Geology
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    • v.32 no.4
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    • pp.525-534
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    • 2022
  • This investigation used two different geophysical logging techniques to confirm the depth to which a sheet pile was driven. Depth was estimated through analysis of the movement speed and three-component movement directions of a P-wave transmitted through the ground. It was also estimated by pole-pole and pole-dipole methods using electrical data logging to measure apparent resistivity. The two methods' respective results were 9.0 m (±1.5 m) and 7.5 m. As field ground conditions will include mixtures of various materials, electrical data logging is judged to be suitable for assessing depth due to its low signal-to-noise ratio.

A Study on the Behavior of Piled Abutment Subjected to Lateral Soil Movement of Soft Ground Improved by Deep Cement Mixing Method (DCM 공법으로 개량된 연약지반의 측방유동을 받는 교대 말뚝기초의 거동 분석에 관한 연구)

  • Choi, Yeonho;Kang, Gyeongho
    • The Journal of Engineering Geology
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    • v.30 no.2
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    • pp.131-145
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    • 2020
  • The construction on these flimsy ground, activation of unsymmetrical surcharges, can often cause of the embankment road lateral flow or the destruction of the activities. In this study, the stability of the abutment pile foundation installed on soft ground and its behavior has been evaluated. The behavior of the abutment pile foundation under lateral flow was studied by verifying the behavior and reinforcement effects of the abutment pile foundation of previous studies about horizontal loads acting on the pile due to the lateral flow of the ground by performing finite element analysis. As a result of the consolidation analyses, the undrained cohesion or the strength of the soft ground, was increased by about 1.1 to 1.8 times by the increase in the strength of the soft ground according to the degree of consolidation. It is deemed reasonable to use 3.8 cm of the allowable displacement both economically and constructively, but considering the importance of the structure and the uncertainty of the ground, measurement shall be carried out during construction and thorough safety management of the lateral flow should be done.

Types of Overlapping Technique in Contemporary Fashion (현대 패션에 나타난 중첩 기법의 유형과 사례분석)

  • Lim, Ji-Ah;Kim, Min-Ja
    • Journal of the Korean Society of Costume
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    • v.63 no.8
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    • pp.106-124
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    • 2013
  • Compared to traditional fashion design, modern fashion design is used as a means that creates original and multiple types of beauty beyond fixed and standardized concept and form. Overlapping technique is the most suitable means to shed classical, authoritative and conservative form and it enables diverse borrowing and quotation for creation. This study aimed to analyze overlapping techniques that are expressed in art, architecture and fashion to find out its characteristics in the field of fashion. The result of this study is as follows. Based on theories of visual perception and advance research, types of overlapping technique were classified as pile, repetition, penetration and transparency. When comparing overlapping techniques in modern fashion with those of painting and architecture, fashion was distinctive in that it had movement and communicativeness through overlapping of fashion and the human body. Therefore, the overlapping technique has wide application and adaptation and can cause specialty, movability, communicativeness and collectivity, which can arouse psychological inspiration.