scholarly journals Effective Length Prediction and Pullout Design of Geosynthetic Strips Based on Pullout Resistance

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6151
Author(s):  
Jeongjun Park ◽  
Gigwon Hong
Keyword(s):  
Effective Area ◽  
Soil Reinforcement ◽  
Effective Length ◽  
Block Type ◽  
Front Wall ◽  
Test Results ◽  
Pullout Strength ◽  
Area Method ◽  
Pullout Resistance ◽  
Pullout Load

In this study, pullout tests were conducted on geosynthetic strips which can be applied to a block-type front wall. Based on the test results, the effective length is predicted, and the pullout design results are presented. In other words, the pullout displacement–pullout load relationship of all geosynthetic strips was analyzed using the pullout test results, and their effective lengths were predicted. It was found that the reinforcement width affected the pullout force for the geosynthetic strips at the same tensile strength. The pullout behavior was evidenced within a range of approximately 0.45 L of the total length of the reinforcement (L) and hardly occurred beyond a certain distance from the geosynthetic strips front regardless of the normal stress. Based on these pullout behavioral characteristics, a method is proposed for the prediction of the effective length (LE) and maximum effective length (LE(max)) of a geosynthetic strip. The pullout strength was compared using the total area and effective area methods in accordance with the proposed method. In the case of the total area method, GS50W (width: 50 mm) and GS70W (width: 70 mm) exhibited similar pullout strengths. The pullout strength by the effective area method, however, was found to be affected by the soil-reinforcement interface adhesion. The proposed method used for the prediction of the effective length of a geosynthetic strip was evaluated using a design case. It was confirmed that the method achieved an economical design in instances in which the pullout resistance by the effective length (LE) was applied compared with the existing method.

scholarly journals SURVIVAL EVALUATION AND SOIL REINFORCEMENT CAPACITY OF FIVE REOPHYTES SPECIES OF THE ATLANTIC RAINFOREST BIOME

FLORESTA ◽  
2019 ◽  
Vol 49 (3) ◽  
pp. 477
Author(s):  
Junior Joel Dewes ◽  
Charles Rodrigo Belmonte Maffra ◽  
Rita Dos Santos Sousa ◽  
Fabrício Jaques Sutili
Keyword(s):  
Survival Rate ◽  
Soil Stabilization ◽  
Land Reclamation ◽  
Survival Rates ◽  
Soil Reinforcement ◽  
Good Survival ◽  
Vegetative Development ◽  
Mechanical Reinforcement ◽  
Pullout Resistance ◽  
Level Of Significance

The aim of this study was to evaluate the survival rate, the vegetative development and vertical pullout resistance of Phyllanthus sellowianus, Salix humboldtiana, Gymnanthes schottiana, Cephallanthus glabratus and Ludwigia elegans propagated by live cuttings. The experiment was conducted at the Federal University of Santa Maria, RS. The experiment was installed in October 2015 and evaluated in June 2016. Experiment was conducted in randomized blocks design with use of 5 plant species and 3 replications. In each block were planted 3 live cuttings of each species, with the total of 45 cuttings for the 3 blocks. The space between plants was of 1 x 1 m. Live cuttings average diameter was 1.7 cm and 60 cm long. Were evaluated the survival rate, morphological variables from shoots, as well as the vertical pullout resistance for each species. The observed survival rates were: P. sellowianus (100%), S. humboldtiana (100%), G. schottiana (83%), %), C. glabratus (67%) e L. elegans (50%), which are statistically different among themselves by Chi-square test (χ ²) at 5% level of significance. The variables, length and diameter of shoots, as well as the vertical pullout resistance are statistically different between species by Tukey’s test at 5% level of significance, and the best results were observed for P. sellowianus and less favorable to L. elegans. The results showed that the evaluated species, excluding L. elegans, had from great to good survival rates. The species P. sellowianus and L. elegans had the major and minor soil mechanical reinforcement capacity, respectively.Keywords: Soil Bioengineering, land reclamation, soil stabilization, vegetative propagation.

Technique to increase the effective length of practical earth electrodes: Simulation and field test results

2013 ◽  
Vol 94 ◽  
pp. 99-105 ◽  
Author(s):  
A. El Mghairbi ◽  
M. Ahmeda ◽  
N. Harid ◽  
H. Griffiths ◽  
A. Haddad
Keyword(s):  
Field Test ◽  
Effective Length ◽  
Test Results

COMPARATIVE BIOMECHANICS: CERVICAL SPINE FACET JOINT VERSUS LATERAL MASS SCREW INSERTION TECHNIQUE

2005 ◽  
Vol 09 (03) ◽  
pp. 113-118
Author(s):  
Boon Horng Kam ◽  
Siaw Meng Chou ◽  
Seang Beng Tan
Keyword(s):  
Cervical Spine ◽  
Facet Joint ◽  
Main Concern ◽  
Lateral Mass ◽  
Pullout Strength ◽  
Insertion Technique ◽  
Pullout Resistance ◽  
Screw Insertion ◽  
System A ◽  
Screw Perforation

This study involves a comparative biomechanics of facet joints (FJ) versus lateral mass (LM) screw insertion technique in the human cadaveric lower cervical spine (C3, C4, C5 and C6). The objective of this study is to understand the promising usage of the facet joint insertion technique and to determine the pullout strength of FJ insertion technique for posterior cervical fixation system. A total of 52 disarticulated human vertebrae (C3–C6) were used in this study. DEXA scan was carried out on all specimens before testing. Cortical screws of 3.5 mm and 4.0 mm were used for both FJ and LM techniques, which were subjected to uniaxial load. From the study made so far, the facet joint technique performed well based on the pullout strength values obtained. Having addressed the main concern on screw perforation of lateral mass technique, this facet joint technique not only demonstrated a significantly higher pullout resistance but it is also a relatively low risk surgical procedure.

Effect of Wetting on the Pullout Resistance of Grouted Soil Nails

2012 ◽  
Vol 226-228 ◽  
pp. 1304-1307
Author(s):  
Jason Y. Wu ◽  
Jr Min Chang
Keyword(s):  
Fine Sand ◽  
Shear Resistance ◽  
Test Results ◽  
Pullout Capacity ◽  
Interface Shear ◽  
Soil Nails ◽  
Soaking Time ◽  
Pullout Resistance ◽  
Soil Nail ◽  
Pullout Tests

In this research, laboratory pullout tests were conducted on grouted soil nails to study the effect of wetting on the interface shear resistance between nail and soil during pullout. Deformed bars with equal size to the true soil nails were used as model nails. The soil used was silty fine sand collected at the site and prepared to a very dense condition. Rainfall infiltration was simulated using duplicated soil nails inundated by water for different periods. Test results indicated that the peak pullout resistance strongly decreases upon wetting, with a reduction of about 60% after soaking for 28 days. However, the experiments showed that there is a threshold water content (or soaking time) beyond which the effect of infiltration on the pullout resistance is reduced. The laboratory protocols developed in this study offered an easy scheme for the prediction of the pullout capacity of a grouted soil nail upon wetting.

Simulation and Numerical Analysis on Anti-Float Anchor by Field Rock and Soil Tests

2014 ◽  
Vol 686 ◽  
pp. 671-675
Author(s):  
Xiang Ling Zhou
Keyword(s):  
Numerical Analysis ◽  
Axial Force ◽  
Field Testing ◽  
Internal Force ◽  
Effective Length ◽  
Test Results ◽  
Future Design ◽  
Anchor Group ◽  
Stress And Deformation ◽  
Rock And Soil

This paper introduces the stress and deformation of anti floating anchor rod and explained the damage. Through field testing and numerical analysis, the article were studied the displacement and internal force of a basement tensile anti float anchor, results showed that: the axial force of bolt tension transfer is top-down transfer, axial force decreases, the stress concentrate on the end. When a force is applied to a certain load, end firstly generate damage, but with the deepening of the axial force, it is greatly reduced, which indicates that the anchor force is an effective length, rather than the longer the anchor pullout force is bigger; anchor group effect is a problem that can not be ignored, because the engineering community for its attention degree is not enough, so that the design of anti floating anchor the lack of a reliable basis, the test results can provide a reference for the future design of anti floating anchor. Prestressed anchors in the tension lock, prestressed loss are regularly.

scholarly journals A PERFORATED MOBILE BREAKWATER FOR FIXED AND FLOATING APPLICATION

1966 ◽  
Vol 1 (10) ◽  
pp. 63 ◽  
Author(s):  
Wilbur Marks
Keyword(s):  
Potential Role ◽  
Front Wall ◽  
Test Results ◽  
Practical Application ◽  
Back Wall ◽  
Mooring Lines ◽  
Application Model ◽  
Perforated Breakwater ◽  
Future Work

A mobile breakwater concept based upon a perforated front wall and solid back wall is presented. The principles of energy dissipation by the system is discussed as well as the potential role of such a device within the framework of practical application. Model test results, comparing the perforated breakwater's response to waves with that of a caisson-type breakwater, are discussed. It is shown that the perforated breakwater experiences less force on the structure when it is fixed to the bottom and less force on the mooring lines when afloat than the caisson-type. However, the perforated breakwater is not more effective in reducing waves, for the conditions tested. Visual observations show that scouring is prevalent when the caisson-type is fixed to the bottom; there is no evidence of scouring with the perforated breakwater. Recommendations are made for future work.

Collapse Strength of Complex Metal Shell Intersections by the Effective Area Method

1998 ◽  
Vol 120 (3) ◽  
pp. 217-222 ◽  
Author(s):  
J. G. Teng
Keyword(s):  
Effective Area ◽  
External Pressure ◽  
Pressure Vessels ◽  
Metal Shell ◽  
Local Pressure ◽  
Area Method ◽  
Different Types ◽  
Bending Stresses ◽  
Slope Discontinuity ◽  
Shell Intersections

Cone-cone intersections and cone-cylinder intersections with or without ring stiffeners are common features in silos, tanks, pressure vessels, piping components, and other industrial shell structures. Under internal or external pressure, these intersections are subject to high circumferential membrane stresses as well as high bending stresses due to the presence of a slope discontinuity. As a result, they are susceptible to local plastic collapse. This paper first provides a summary of the effective area method initially proposed by Rotter for the plastic limit loads of cone-cylinder intersections in silos. The method is then generalized for complex intersections of cones and cylinders under uniform pressure and improved by including the local pressure effect. Results from the effective area method are compared with rigorous finite element results for a number of cases to demonstrate its accuracy. It is shown that the method is not only elegant and accurate, but also leads to a single simple formula for different types of intersections which is particularly suitable for codification purposes.

Pullout Behavior of Steel Mechanically Stabilized Earth Reinforcements

2018 ◽  
Vol 2672 (52) ◽  
pp. 238-250 ◽  
Author(s):  
Timothy A. Wood ◽  
William D. Lawson ◽  
Priyantha W. Jayawickrama ◽  
James G. Surles
Keyword(s):  
Axial Force ◽  
Stress Reduction ◽  
Soil Reinforcement ◽  
Mechanically Stabilized Earth ◽  
Pullout Resistance ◽  
Pullout Tests ◽  
Earth Reinforcement ◽  
Embedment Length ◽  
Mechanically Stabilized ◽  
Reinforcement Interaction

Instrumented pullout tests of unprecedented scope and scale explore the pullout behavior for three steel mechanically stabilized earth reinforcement types: ribbed strips, ladder-like strips, and three-wire bar mat grids. These data quantify the distribution of pullout resistance between longitudinal elements and illustrate the nature of certain reinforcement deformations. Consistent with characteristic inextensible pullout behavior and soil-reinforcement interaction, synthesized strain-gage data illustrate linear stress reduction along the embedment length during pullout for all three reinforcement styles. For ladder-like strips, the axial force divides evenly between the two longitudinal elements. For the three-wire bar mat grid, the center bar carries approximately 40% of the axial force, whereas each outside bar carries approximately 30% of the axial force. Observed pullout-induced deformation in the transverse elements of three-wire bar mat grids having widely spaced longitudinal bars is conceptually different from extensible behavior and suggests the need for refinement in current pullout resistance formulations.

Experimental basis for the effective length factors of steel solid round cross-braced diagonals in CSA Standard S37-01

2002 ◽  
Vol 29 (3) ◽  
pp. 430-435
Author(s):  
Yongcong Ding ◽  
Kalid S Jaboo ◽  
Yean Sun ◽  
Murty K.S Madugula
Keyword(s):  
Effective Length ◽  
Test Results ◽  
Experimental Basis ◽  
Failure Loads ◽  
Lattice Tower ◽  
Communication Towers ◽  
Round Cross ◽  
Compressive Resistance

The effective length factors for steel solid round diagonals in all-welded communication towers are investigated in this paper to provide experimental basis for the relevant clauses in CSA Standard S37-01. The results of a total of 31 all-welded lattice tower specimens with three types of cross-braced diagonals are presented. The failure loads for these members were determined from the maximum axial strains measured during the tests. The effective length factors were then back-calculated from the experimental failure loads using the compressive resistance formulas. The test results showed that even the significantly lower effective length factors specified in CSA S37-01, compared to CSA S37-94, are still conservative.Key words: all-welded towers, communication towers, cross-bracing, effective length factors, solid round steel diagonals.

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