• Title/Summary/Keyword: pull - out capacity

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Response of square anchor plates embedded in reinforced soft clay subjected to cyclic loading

  • Biradar, Jagdish;Banerjee, Subhadeep;Shankar, Ravi;Ghosh, Poulami;Mukherjee, Sibapriya;Fatahi, Behzad
    • Geomechanics and Engineering
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    • v.17 no.2
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    • pp.165-173
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    • 2019
  • Plate anchors are generally used for structures like transmission towers, mooring systems etc. where the uplift and lateral forces are expected to be predominant. The capacity of anchor plate can be increased by the use of geosynthetics without altering the size of plates. Numerical simulations have been carried out on three different sizes of square anchor plates. A single layer geosynthetic has been used as reinforcement in the analysis and placed at three different positions from the plate. The effects of various parameters like embedment ratio, position of reinforcement, width of reinforcement, frequency and loading amplitude on the pull out capacity have been presented in this study. The load-displacement behaviour of anchors for various embedment ratios with and without reinforcement has been also observed. The pull out load, corresponding to a displacement equal to each of the considered maximum amplitudes of a given frequency, has been expressed in terms of a dimensionless breakout factor. The pull out load for all anchors has been found to increase by more than 100% with embedment ratio varying from 1 to 6. Finally a semi empirical formulation for breakout factor for square anchors in reinforced soil has also been proposed by carrying out regression analysis on the data obtained from numerical simulations.

An Experimental Study on the Behavior of Miscopiles installed in Weathered Weak Rock (풍화암 지반에 설치된 소구경말뚝의 거동에 관한 연구)

  • 박성재;정경환;이세훈
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.389-396
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    • 1999
  • In this study compressive and tensile load tests have been performed to investigate reinforcing effect and load transfer mechanism of small diameter piles installed in the foundation soil for the marine suspension bridge. Load tests were carried out on steel plate with diameters of 50cm, 100cm and 150cm varying loads starting from 39 tons up to 314 tons. Small diameter piles were proved to behavior like as friction piles and loads were not transmitted to the bottom of piles. From pull-out tests, the uplift capacity of small diameter piles was largely influenced by reinforcing materials compared to frictional resistance between piles and adjacent soils. The bearing capacity of small diameter piles appeared to be higher than the ultimate bearing capacity evaluated using static formulae. The load carrying capacity of small diameter piles was superior to the bored piles with a similar size. Thus, ultimate bearing capacity estimated from static formulae can provide conservative designs and thereby resulting in economic disadvantages. A further study to accumulate data regarding various soil conditions is recommended for an improved estimation of bearing capacity of piles with small diameter.

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A Study on Pull-out Capacity and Shear resistance strength change by grasses (초본류에 의한 인발저항력 및 전단저항력 변화에 관한 연구)

  • Kim, Taegyun;Chae, Soo Kwon;Chun, Seung Hoon
    • Journal of Wetlands Research
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    • v.15 no.4
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    • pp.431-440
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    • 2013
  • It was tested in field that a Pull-out Capacity and Shear resistance strength change of reed, common reed and sedge which were planted by mat-type turf and used for revegetation of bank. The testes were done for 9 weeks from end of May and the grasses were planted on sandy soil. Roots grew fastly after planted and increasement of a common reed and sedge root were reduced after 4 weeks but increasement of reed roots were not reduced. The difference of increasement of roots is due to a difference of propagation method. Sedge propagate by seed. Reed and commom reed propagate by seed and subterranean stem and reed has bigger subterranean stem than common reed. So increasement of common reed and sedge roots were slow than reed. By root growth pattern, increasement of pull-out capacity and shear resistance strength showed very similar way of root growth, those of common reed and sedge were fast in early stage of cultivation but were reduced. But increasement of pull-out capacity and shear resistance strength of reed was not reduced. A Maximum shear resistance strength called critical shear resistance strength of common reed and sedge can be Analyzed at 11 weeks after planted.

Evaluation of Steel Pull-Out of Reinforced Concrete Beam-Column Joints (철근콘크리트 보-기둥 접합부 철근의 뽑힘 평가)

  • Woo, Jae-Hyun;Park, Jong-Wook;Kim, Byoung-Il;Lee, Jung-Yoon
    • Journal of the Korea Concrete Institute
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    • v.22 no.6
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    • pp.833-841
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    • 2010
  • In this report, the test results of five reinforced concrete beam-column joint subjected to cyclic load are presented. The main purpose of the research is to investigate the influence of the steel pull-out of the beam-column joints to the shear and ductile capacity of the RC beam-column assembles. In addition, the influence of the amount of beam reinforcement to the joint shear and ductile capacity is evaluated. Test results indicate that the yield penetration of steel bar increases as the joint shear strength ratio, $V_{j1}/V_{jby}$ decreases. And the slippage of the steel bars are varied according to the region of the beam-column joints. The pull-out of the steel bars of five specimens was almost the same regardless of the joint shear strength ratio, $V_{j1}/V_{jby}$. Because it was affected by not only the yield penetration of steel bar but also the axial elongation in the plastic hinge.

Evaluation of Skin Friction Using Tensile Load Testing of CPR Piles (CPR 말뚝의 인발재하시험을 통한 주면마찰력 평가)

  • Ko, Chin-Surk;Kim, Jung-Han;Noh, Jeongdu;Kang, Seong-Seung
    • The Journal of Engineering Geology
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    • v.30 no.1
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    • pp.59-69
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    • 2020
  • Pull-out load tests were performed on a CPR (Compaction grouting compound Pile with Reinforce) test pile, with skin friction being evaluated by the yield load and allowable bearing capacity after analyzing load-displacement curves and load-settlement curves. Results of the CPR test piles analyzed from the load-displacement curves show that the yield load and allowable bearing capacity of the large-diameter CPR test pile were about 1.4 times larger than that of the small-diameter pile. Results of the load-settlement curves reveal that the allowable bearing capacity of the CPR test pile with diameter of D500 was 1.2~2.1 times greater than that of the pile with diameter of D400. However, the allowable bearing capacity calculated using Fuller's analysis differed substantially from that determined using the P (Pull-out load) - S (Settlement) and log P - log S curves. Therefore, calculation of the allowable bearing capacity using Fuller's analysis is shown to be inappropriate.

An Experimental Study on the Engineering Properties of HPFRCC According to Kinds, Shapes and Volume Fraction of Fibers (섬유의 종류, 형상 및 치환율에 따른 HPFRCC의 공학적 특성에 관한 실험적 연구)

  • 김영덕;조봉석;김재환;김규용;최경렬;김무한
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2003.05a
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    • pp.59-62
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    • 2003
  • Kinds, shapes and fraction ratios of fibers have influence on properties of HPFRCC(High-Performance Fiver Reinforced Cementitious Concrete ) like bending strength, strain capacity and fracture toughness. For example, hydrophilic fibers have different chemical bond strength from hydrophobic fibers, fiber shapes influence on fiber pull-out and rupture, and fiber volume fraction influence on bending strength. In this study, to estimate influences of kinds, shapes and fraction ratios of fibers, we make HFRCC with 3 kind of fiber in various volume fraction of fiber and compare cracking, bending strength and fracture toughness. As the results, bending strength of HPFRCC was increased as fiber volume fraction was Increase and fiber tensile strength was increase, and strain capacity and fracture toughness of HFRCC was higher in fiber pull-out fracture than in fiber rupture fracture. And HFRCC showing pseudo strain hardening has higher fiber reinforce efficiency than others.

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Failure Mechanism for Pull-Out Capacity of Headed Reinforcement (Head Reinforcement 인발강도를 위한 파괴 메캐니즘)

  • 홍성걸;최동욱;권순영
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.05a
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    • pp.233-238
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    • 2002
  • This study presents failure mechanisms for the pull-out strength of headed reinforcement for upper bound solution based on the limit theorem. The failure mechanisms to be presented follow the failure surface pattern of punching shear failure found in the joints of slab with a column. Several failure surfaces of the mechanisms have different characteristics for dissipation works and these mechanisms are able to interpret the role of bar details surrounding headed reinforcement.

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Pull - out Capacity of Ground Anchor in Weathered Rock (풍화암 지반에 정착된 앵커의 인발저항 특성)

  • 이승환;황의석;이봉열;김학문
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.435-442
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    • 2002
  • Fluid Confirmation Tests(FCT) on 1500 ground Anchors install in weathered rock were carried out to investigate upper and lower limit of elastic elongation, frictional resistant of fixed anchor body, mobilized angle between anchor body and soil. All the measured data were analysed and compared with theoretical equations. The frictional angles of diaphragm wall and anchorage system in weathered rock showed nonlinear curve between upper and lower limit of standard elongation. The FCT results indicated that the frictional resistant angles increased with higher values of surcharge load. The quality assurance on the fixed anchor location was investigated by means of measuring elastic elongation during the FCT, and comparing these with theoretical design length, the quality of anchors in this particular site found to be above average standard. The results of this research works with provide valuable guide line on quality assurance of anchors system as well as resonable prediction of friction resistance between the fixed anchor body and the weathered rock.

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Three-dimensional numerical analysis of nonlinear phenomena of the tensile resistance of suction caissons

  • Azam, Arefi;Pooria, Ahad;Mehdi, Bayat;Mohammad, Silani
    • Geomechanics and Engineering
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    • v.32 no.3
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    • pp.255-270
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    • 2023
  • One of the main parameters that affect the design of suction caisson-supported offshore structures is uplift behavior. Pull-out of suction caissons is profoundly utilized as the offshore wind turbine foundations accompany by a tensile resistance that is a function of a complex interaction between the caisson dimensions, geometry, wall roughness, soil type, load history, pull-out rate, and many other parameters. In this paper, a parametric study using a 3-D finite element model (FEM) of a single offshore suction caisson (SOSC) surrounded by saturated soil is performed to examine the effect of some key factors on the tensile resistance of the suction bucket foundation. Among the aforementioned parameters, caisson geometry and uplift loading as well as the difference between the tensile resistance and suction pressure on the behavior of the soil-foundation system including tensile capacity are investigated. For this purpose, a full model including 3-D suction caisson, soil, and soil-structure interaction (SSI) is developed in Abaqus based on the u-p formulation accounting for soil displacement (u) and pore pressure, P.The dynamic responses of foundations are compared and validated with the known results from the literature. The paper has focused on the effect of geometry change of 3-D SOSC to present the soil-structure interaction and the tensile capacity. Different 3-D caisson models such as triangular, pentagonal, hexagonal, and octagonal are employed. It is observed that regardless of the caisson geometry, by increasing the uplift loading rate, the tensile resistance increases. More specifically, it is found that the resistance to pull-out of the cylinder is higher than the other geometries and this geometry is the optimum one for designing caissons.

An Experimental Study on the Engineering Properties of HPFRCC According to Kinds, Shapes and Volume Fraction of Fibers (섬유의 종류, 형상 및 치환율에 따른 HPFRCC의 공학적 특성에 관한 실험적 연구)

  • Kim, Young-Duck;Cho, Bong-Suk;Kim, Jae-Hwan;Kim, Gyu-Yong;Choi, Kyung-Yuel;Kim, Moo-Han
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2003.11a
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    • pp.59-62
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    • 2003
  • Kinds, shapes and fraction ratios of fibers have influence on properties of HPFRCC(High-Performance Fiver Reinforced Cementitious Concrete) like bending strength, strain capacity and fracture toughness. For example, hydrophilic fibers have different chemical bond strength from hydrophobic fibers, fiber shapes influence on fiber pull-out and rupture, and fiber volume fraction influence on bending strength. In this study, to estimate influences of kinds, shapes and fraction ratios of fibers, we make HFRCC with 3 kind of fiber in various volume fraction of fiber and compare cracking, bending strength and fracture toughness. As the results, bending strength of HPFRCC was increased as fiber volume fraction was increase and fiber tensile strength was increase, and strain capacity and fracture toughness of HFRCC was higher in fiber pull-out fracture than in fiber rupture fracture. And HFRCC showing pseudo strain hardening has higher fiber reinforce efficiency than others.

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