• Title/Summary/Keyword: Geosynthetic

Search Result 246, Processing Time 0.023 seconds

Evaluation of Creep Reduction Factor for Geosynthetic Strip Reinforcement with Folding Grooves (접힘홈이 형성된 띠형 섬유보강재의 크리프 감소계수 평가)

  • Lee, Kwang-Wu;Cho, Sam-Deok
    • Journal of the Korean Geosynthetics Society
    • /
    • v.17 no.4
    • /
    • pp.213-224
    • /
    • 2018
  • In this study, a series of accelerated creep tests (SIM) was carried out on geosynthetic strip reinforcements with folding grooves having different tensile strengths (15 kN, 25 kN, 35 kN, 50 kN, 70 kN, and 90 kN) to analyze creep characteristics and to assess creep reduction factors. In particular, long-term creep tests were conducted on geosynthetic strip reinforcements with 25 kN tensile strength, which is widely used, to compare and analyze the accelerated creep test results. As a result, the creep reduction factor increased with an increasing design life of reinforcement. In addition, geosynthetic strip reinforcement using the same material and manufacturing method showed similar creep reduction factors at the same design life for different tensile strengths. When both long-term and accelerated creep test data were used, the creep reduction factors from the accelerated test were estimated to be 5.9%~7.1% less than those from the long-term creep test for the design life ranging from 50 to 100 years.

3D Finite Element Analysis on Load Carrying Capacity of Geosynthetic-reinforced Bridge Abutment (보강토 교대 구조물의 하중지지 특성에 관한 3차원 유한요소해석)

  • Yoo, Chung-Sik
    • Journal of the Korean Geotechnical Society
    • /
    • v.26 no.5
    • /
    • pp.15-26
    • /
    • 2010
  • This paper presents the results of a three-dimensional finite element analysis on a geosynthetic-reinforced bridge abutment. Examples on the use of mechanically stabilized earth bridge abutment in north America are first presented. A three-dimensional finite element analysis on a 4.8 m high, 14 m wide geosynthetic-reinforced bridge abutment was performed to investigate the 3D behavior of the geosynthetic-reinforced bridge abutment and the load carrying capacity of the bridge abutment in the three-dimensional space. The results are then presented in a way that the three-dimensional behavior of the abutment can be identified in terms of wall displacements and reinforcement forces. It is shown that the wall facing displacements as well as the reinforcement forces in the abutment are smaller than those computed based on a plane strain approximation.

Integral Bridge System with Geosynthetic-Reinforced Backfill

  • Tatsuoka, Fumio
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2007.09a
    • /
    • pp.39-52
    • /
    • 2007
  • A new type bridge combining an integral bridge and a pair of geosynthetic-reinforced soil (GRS) retaining walls having full-height rigid (FHR) facings, called the GRS integral bridge, is proposed. The geosynthetic reinforcement layers are connected to the FHR facings (i.e., RC parapets) that are integrated with a girder without using any girder-support. GRS integral bridges are basically much more cost-effective in construction and long-term maintenance while having a much higher seismic stability than conventional-type bridges having a girder via movable and fixed supports on a pair of cantilever abutments. GRS integral bridges are better than bridges using GRS retaining walls as abutments and also than conventional integral bridges with unreinforced backfill. To validate the above, a series of static cyclic lateral loading tests of the facing and a series of shaking table tests were performed on smallscaled models of different bridge types.

  • PDF

Strain localization and failure load predictions of geosynthetic reinforced soil structures

  • Alsaleh, Mustafa;Kitsabunnarat, Akadet;Helwany, Sam
    • Interaction and multiscale mechanics
    • /
    • v.2 no.3
    • /
    • pp.235-261
    • /
    • 2009
  • This study illustrates the differences between the elasto-plastic cap model and Lade's model with Cosserat rotation through the analyses of two large-scale geosynthetic-reinforced soil (GRS) retaining wall tests that were brought to failure using a monotonically increasing surcharge pressure. The finite element analyses with Lade's model were able to reasonably simulate the large-scale plane strain laboratory tests. On average, the finite element analyses gave reasonably good agreement with the experimental results in terms of global performances and shear band occurrences. In contrast, the cap model was not able to simulate the development of shear banding in the tests. In both test simulations the cap model predicted failure loads that were substantially less than the measured ones.

The effectiveness of geosynthetic reinforcement, tamping, and stoneblowing of railtrack ballast beds under dynamic loading: DEM analysis

  • Lobo-Guerrero, Sebastian;Vallejo, Luis E.
    • Geomechanics and Engineering
    • /
    • v.2 no.3
    • /
    • pp.161-176
    • /
    • 2010
  • Discrete Element Method (DEM) simulations were developed to investigate the effectiveness of geosynthetic reinforcement and the effectiveness of maintenance techniques performed on a simulated ballast bed subjected to dynamic loading. The results from four samples subjected each one to a total of 425 load cycles are presented: one unreinforced and unmaintained sample, one unmaintained but reinforced sample, one unreinforced sample subjected to maintenance in the form of stoneblowing after 200 load cycles, and one unreinforced sample subjected to maintenance in the form of tamping after 200 load cycles. The obtained values of permanent deformation as a function of the applied number of load cycles for the four cases are presented together allowing a comparison of the effectiveness of each technique. Moreover, snapshots of the simulated track sections are presented at different moments of the simulations. The simulations indicated that the geosynthetic reinforcement may not be beneficial for the analyzed case while stoneblowing was the most effective maintenance technique.

Visualization of bulging development of geosynthetic-encased stone column

  • Zhou, Yang;Kong, Gangqiang;Peng, Huaifeng;Li, Chunhong;Qin, Hongyu
    • Geomechanics and Engineering
    • /
    • v.18 no.3
    • /
    • pp.329-337
    • /
    • 2019
  • This paper presents an experimental investigation about visualization of bulging development of geosynthetic-encased stone column (GESC) based on the digital image correlation (DIC) technique and transparent soil. Visual model tests on GESC and ordinary stone column (OSC) were carried out. In order to delete the warping effect resulting from transparent soil and experiment setup, a modification for experiment results was performed. The bulging development process of the GESC and the displacement field of the surrounding soil were measured. By comparing with the existing experimental and theoretical results, it demonstrates that the model test system developed for studying the continuous bulging development of GESC is suitable. The current test results show that the bulging depth of GESC ranges from 1.05 to 1.40 times the diameter of GESC. The influence depth of GESC bulging on surrounding soil displacement is 0~3 the times diameter of GESC.

Evaluation on Stability of Reinforced Earth Wall using Geosynthetic Strip with Rounded Band Anchor (띠형 섬유보강재가 적용된 블록식 보강토옹벽의 안정성 평가)

  • Lee, Kwang-Wu;Cho, Sam-Deok;Han, Jung-Geun;Hong, Ki-Kwon
    • Journal of the Korean Geosynthetics Society
    • /
    • v.11 no.3
    • /
    • pp.43-51
    • /
    • 2012
  • This paper describes the stability evaluation of reinforced earth wall using geosynthetic strip based on field test. The wall facing, which is applied in field, is able to present excellent scenery, and the reinforcement has improvement effect of pullout resistance based on rounded band anchor. The measurement is conducted according to construction elapsed time of structure for earth pressure, horizontal displacement of wall facing and reinforcement strain in field test. The evaluation results show that the measured earth pressure is less than theoretical earth pressure due to dispersion effect of earth pressure by geosynthetic strip. The horizontal displacement of wall facing is also satisfied a empirical criteria. The measured strain of reinforcement had nearly no effect on stability of the reinforced earth wall. Therefore, the geosynthetic strip with rounded band anchor can be applied in the reinforced earth wall, and the reinforced earth wall with geosynthetic strip can be commonly used in field because it has a structural stability.

Evaluation of Strain Distribution and Pullout Strength based on Width and Horizontal Spacing of Geosynthetic Strip (띠형 섬유보강재의 폭과 설치간격에 따른 변형률 분포 및 인발강도 특성 평가)

  • Lee, Kwang-Wu;Cho, Sam-Deok;Han, Jung-Geun;Hong, Ki-Kwon
    • Journal of the Korean Geosynthetics Society
    • /
    • v.11 no.2
    • /
    • pp.39-47
    • /
    • 2012
  • This paper describes large-scale pullout test results of geosynthetic strip, which can be applied in reinforced earth wall with block-type wall facing. The pullout tests are conducted to evaluate the strain distribution, the induced pullout force and the pullout strength. The maximum pullout force is appeared regardless of reinforcement width and normal stress when end displacement is less than 15 mm. The pullout behavior based on horizontal spacing of reinforcement was similar in relationship between pullout force and end displacement. The strain distribution and pullout force distribution of the geosynthetic strip are concentrated in the front part of reinforcement, and it appeared clearly in higher normal stress condition This means that the pullout behavior of geosynthetic strip is affected by the bond between soil and friction resistance reinforcement according normal stress. Therefore, the pullout resistance design is reasonable when pullout behavior of geosynthetic strip should be evaluated by effective length considering tensile characteristic.

Water Barrier Performance of Rubber Related Geosynthetics for Road Construction

  • Jeon, Han-Yong
    • Proceedings of the Korean Fiber Society Conference
    • /
    • 2003.10a
    • /
    • pp.21-22
    • /
    • 2003
  • 4 types rubber related geosynthetics were manufactured to examine the performance to for applications to the civil and geotechnical fields, especially to the road construction. Reinforcement and water barrier function of these geosynthetics were interpreted as the important properties. Fiber glass mat based and geogrid based geosynthetics showed the excellent mechanical properties as. Also elastomeric bitumen based geosynthetic showed the highest permittivity. From this, it i s thought that this geosynthetic is suitable for water barrier under specific load condition.

  • PDF

Analysis of Reduction Factors to Creep Deformation of Reinforced Geosynthetics

  • Jeon, Han-Yong;Yuu, Jung-Jo;Mok, Mun-Sung
    • Proceedings of the Korean Fiber Society Conference
    • /
    • 2003.10a
    • /
    • pp.104-104
    • /
    • 2003
  • Geosynthetic Reinforcements - membrane drawn type, warp/knitted type, junction bonded type and composite type geogrids, strip type reinforcement - were used to compare the long-term perfor-mance by total factor of safety with reduction factors during service periods. To evaluate the reduction factors, wide-width tensile property, installation damage, creep deformation, chemical and biological degradation tests were performed. Long-term design strengths of geosynthetic reinforcements were calculated by using GRI standard Test Method GG4.

  • PDF