scholarly journals Mechanical Behavior of Triaxial Geogrid Used for Reinforced Soil Structures

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Jun Zhang ◽  
Wen-Zhao Cao ◽  
Yan-Jun Zhou
Keyword(s):  
Tensile Strength ◽  
Mechanical Behavior ◽  
Laboratory Tests ◽  
Reinforced Soil ◽  
Geological Hazards ◽  
Grid Structure ◽  
Interface Friction ◽  
Pullout Tests ◽  
Soil Structures ◽  
Improved Performance

Geosynthetics-reinforced soil (GRS) structures have been widely used for the prevention of geological hazards. As a recently introduced product, the triaxial geogrid has been confirmed to provide improved performance due to the more stable grid structure. This paper presents an evaluation of the mechanical behavior based on a series of laboratory tests. The unconfined tensile strength of biaxial geogrid and triaxial geogrid in different loading directions relative to the orientation of ribs was investigated. Then, more than 8 pullout tests were conducted on the triaxial geogrid specimens embedded in the compacted sand. The internal displacements along the geogrid length were monitored. The results show that the triaxial geogrid has been shown to provide nearly uniform tensile strength in all loading directions as compared with the biaxial geogrid. The triaxial geogrid deformation is mainly characterized by rib bending and nodal distortion along with an inward squeeze perpendicular to the pullout direction. The interface friction between the soil and the geogrid develops in a progressive mode, and an elasto-plastic-softening characteristic is detected experimentally due to the extensibility of geogrid.

Comparison of Pullout Behaviour on Sand between Planer Grid Forms and Grid with Rib of Reinforcement

2010 ◽  
Vol 143-144 ◽  
pp. 1012-1016
Author(s):  
Yong Liang Lin ◽  
Meng Xi Zhang ◽  
Chun Cai
Keyword(s):  
Reinforced Soil ◽  
Grid Size ◽  
Soil Reinforcement ◽  
Testing Program ◽  
Pullout Force ◽  
Pullout Resistance ◽  
Pullout Tests ◽  
Soil Structures ◽  
Pullout Behaviour ◽  
Grid Reinforcement

In conventional reinforced soil structures, the reinforcements are often laid horizontally in the soil. In this paper, a new concept of grid reinforcement with ribbed inclusions is proposed. In the proposed of soil reinforcement, besides conventional grid reinforcements, some vertical and 3D reinforcing rib are also placed in the soil. Pullout tests are necessary in order to study the interaction behavior between soil and geosynthetics in the anchorage zone. Then, a series of pullout tests are conducted and the various parameters studied in this testing program include rib height and grid size of reinforcement. The result shows that the ultimate pullout force of plexiglass with rib is significantly larger than ordinary ones in the same normal stress. Ultimate pullout resistance increased as the increase of the height of tooth, and also is significantly impacted by grid size.

scholarly journals Experimental Investigations on Pullout Behavior of HDPE Geogrid under Static and Dynamic Loading

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Zheng Zuo ◽  
Guangqing Yang ◽  
He Wang ◽  
Zhijie Wang
Keyword(s):  
Dynamic Loading ◽  
Static Loading ◽  
Coarse Sand ◽  
Reinforced Soil ◽  
Growth Patterns ◽  
Experimental Investigations ◽  
Pullout Resistance ◽  
Pullout Tests ◽  
Soil Structures ◽  
Static And Dynamic Loading

This paper describes a series of laboratory pullout tests that were performed to investigate the pullout behavior of high-density polyethylene (HDPE) uniaxial geogrid subjected to static and dynamic loading. Pullout tests were conducted on HDPE geogrid reinforced coarse sand under normal static loading (60–300 kPa), dynamic loading with different amplitudes (20, 40, and 60 kPa), and different frequencies (2, 4, and 6 Hz) by using the newly developed pullout apparatus. The results indicated that the pullout resistance of geogrid presented different growth patterns with the increase of normal loads under static loading. The amplitude and frequency both had significant effects on the interaction between reinforcement and soil, and the increment of the pullout resistance was 0.6 kN and 0.3 kN, respectively. The effect of dynamic loading on the soil-geogrid interface can be gradually equivalent to that of static loading corresponding to the balance position of dynamic loading with the increase of frequency compared with the static loading. The results of this study are helpful for the selection of the strength of the reinforcement in different locations and to simplify the study on the stress of reinforcement in reinforced soil structures under traffic loads.

Microstructure and physical properties of composite nonwovens produced by incorporating cotton fibers in elastic spunbond and meltblown webs for medical textiles

2021 ◽  
pp. 152808372110042
Author(s):  
Partha Sikdar ◽  
Gajanan S Bhat ◽  
Doug Hinchliff ◽  
Shafiqul Islam ◽  
Brian Condon
Keyword(s):  
Tensile Strength ◽  
Physical Properties ◽  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Barrier Properties ◽  
Cotton Fibers ◽  
Adult Care ◽  
Medical Textiles ◽  
Improved Performance

The objective of this research was to produce elastomeric nonwovens containing cotton by the combination of appropriate process. Such nonwovens are in demand for use in several healthcare, baby care, and adult care products that require stretchability, comfort, and barrier properties. Meltblown fabrics have very high surface area due to microfibers and have good absorbency, permeability, and barrier properties. Spunbonding is the most economical process to produce nonwovens with good strength and physical properties with relatively larger diameter fibers. Incorporating cotton fibers into elastomeric nonwovens can enhance the performance of products, such as absorbency and comfort. There has not been any study yet to use such novel approaches to produce elastomeric cotton fiber nonwovens. A hydroentangling process was used to integrate cotton fibers into produced elastomeric spunbond and meltblown nonwovens. The laminated web structures produced by various combinations were evaluated for their physical properties such as weight, thickness, air permeability, pore size, tensile strength, and especially the stretch recovery. Incorporating cotton into elastic webs resulted in composite structures with improved moisture absorbency (250%-800%) as well as good breathability and elastic properties. The results also show that incorporating cotton can significantly increase tensile strength with improved spontaneous recovery from stretch even after the 5th cycle. Results from the experiments demonstrate that such composite webs with improved performance properties can be produced by commercially used processes.

Mechanical Behavior for some Cobalt Alloys

2015 ◽  
Vol 1114 ◽  
pp. 9-12
Author(s):  
Alexandru Ghiban ◽  
Brandusa Ghiban ◽  
Cristina Maria Borţun ◽  
Nicolae Serban ◽  
Mihai Buzatu
Keyword(s):  
Tensile Strength ◽  
Chemical Composition ◽  
Mechanical Behavior ◽  
Mechanical Characteristics ◽  
Fractographic Analysis ◽  
Cobalt Alloys ◽  
Dental Alloys ◽  
Bending Tests ◽  
Longitudinal Modulus

Four compositions of some usually commercial dental alloys were investigated in order to determine the mechanical characteristics and fractographic analysis of tensile and bending tests surfaces. A correlation between chemical composition (either molybdenum or molybdenum and chromium contents) and mechanical characteristics (longitudinal modulus, tensile strength and elongation) were finally done.

Design and Mechanical Evaluation of Sutureless Implants for the Surgery Treatment of Rotator Cuff Tears

2021 ◽  
Author(s):  
Marcília Valéria Guimarães ◽  
Elton Bonifácio ◽  
Thiago Carmo ◽  
Cleudmar Araújo
Keyword(s):  
Rotator Cuff ◽  
Mechanical Behavior ◽  
Functional Disability ◽  
Statistical Significance ◽  
Testing Machine ◽  
Rotator Cuff Tears ◽  
Suture Anchors ◽  
Pullout Strength ◽  
Rigid Foam ◽  
Pullout Tests

Abstract Rotator cuff (RC) tears cause pain and functional disability of the shoulder. Despite advances in suture anchors, there are still reports about the incidence of surgical-related injuries to RC mainly associated with sutures. The purpose of this study was to design and evaluate the mechanical behavior of sutureless implants to repair RC tears. We hypothesized that the implants present mechanical characteristics suitable for the surgical treatment of RC tears as suture anchors. Three different implants (T1,T2,T3) were designed and fabricated with titanium: T1 has two rods and rectangular head; T2 has two rods with a small opening and enlarged rectangular head and T3 has three rods and a circular head. The implants were fixed in rigid polyurethane foam blocks by a series of blows, and the applied mechanical loads along with the number of blows were quantified. Pullout tests using tapes fixed between the implant head and testing machine grip were conducted until implant failure. The maximum pullout strength and displacement of the implant relative to the rigid foam block were computed. Statistical significance was set at p < 0.05. Owing to its geometric configuration, implant T2 presented the best characteristics related to stability, strength, and ease of insertion. Implant T2 confirms our hypothesis that its mechanical behavior is compatible with that of suture anchors which could lead to the reduction of RC repair failures and simplify the arthroscopic procedure.

Field observations on the load–strain–time behaviour of geogrid reinforcement

1994 ◽  
Vol 31 (4) ◽  
pp. 564-569 ◽  
Author(s):  
R.J. Fannin
Keyword(s):  
Tensile Strength ◽  
Field Data ◽  
Constant Load ◽  
Reinforced Soil ◽  
Mean Annual Temperature ◽  
Creep Tests ◽  
Geogrid Reinforcement ◽  
Rapid Loading ◽  
Strip Test ◽  
Relationship Of

Field data are reported that describe the load–strain–time relationship of geogrid reinforcement in a reinforced soil structure. The data are for a period exceeding 5 years and reveal a continued strain in the reinforcement, which occurs at nearly constant load. The response to loading is attributed to creep of the polymeric material. A comparison of the field data with laboratory isochronous load–strain curves, from rapid loading creep tests performed at a temperature similar to the mean annual temperature in the backfill soil, shows the curves describe very well the magnitude of creep strains observed in the field. Implications of the load–strain–time performance data are assessed with reference to the use in design of a tensile strength established from the rapid-loading creep test and wide-width strip test. The need to clarify, in design of polymeric reinforced soil structures, between a safe and allowable tensile strength is emphasized. Key words : reinforced soil, geogrid, creep, tensile strength, strain.

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