scholarly journals Characteristics of the Interface between Bamboo Grids and Reinforced Soil of High-Filled Embankments in Loess Areas

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jingwei Zhang ◽  
Jia Li ◽  
Julong Wang ◽  
Shuaiqi Xu
Keyword(s):  
Shear Rate ◽  
Shear Resistance ◽  
Bite Force ◽  
Reinforced Soil ◽  
Influential Factors ◽  
Grid Spacing ◽  
Shear Properties ◽  
Friction Resistance ◽  
Loess Soils ◽  
Durability Analysis

There are a large number of high-filled and deep-dug highways in loess areas. The differential settlement between the filled and undisturbed soils is the main cause of damage. Bamboo grids are good reinforcement and flexural tensile materials for highway subgrades, and the properties of the interface between the bamboo grid and loess soil affect the safety and stability of embankments. First, the feasibility of bamboo grid application in high-filled embankments in loess areas was verified based on a durability analysis and test of the mechanical properties of bamboo. Then, a series of large-scale direct shear tests were carried out to determine the shear properties of the interface between bamboo grids and loess soils. The influential factors of vertical stress, shear rate, grid spacing, and compactness on the shear properties were studied, and the related mechanism was discussed. The results show that bamboo grids enhance the shear strength of loess soils more than geogrids under different vertical stresses because of the passive friction resistance between the vertical and horizontal ribs and soil particles, the bite force of particle skeletons, and the surface friction of grids. Bamboo grids enhance the stability and shear resistance of soils because of their good deformation performance, and thus, the shear rate effect within 7 mm/min can be negligible. The greater the relative compaction of the subgrade soil, the better the reinforcement effect owing to the greater cohesive force, greater internal friction angle, and better bite force. The variation in grid spacing changes the embedded effect of soil, side friction resistance, and size of the contact area. The shear resistance has an optimal value, which first increases and then decreases. Therefore, in practical applications, it is necessary to test the optimal bamboo grid spacing for a project.

scholarly journals Construction Experiment of Reinforced Soil Wall Using Reinforcement Member Incorporating Both Friction Resistance and Bearing Resistance

2017 ◽  
Vol 12 (1) ◽  
pp. 33-46
Author(s):  
Hirohisa MUTO ◽  
Takashi KAMIYA ◽  
Akihiko NAGANUMA ◽  
Takeshi KODAKA ◽  
Cui YING ◽  
...  
Keyword(s):  
Reinforced Soil ◽  
Friction Resistance ◽  
Reinforced Soil Wall

scholarly journals Experimental investigation on shear properties of warp-knitted brush fabrics

2020 ◽  
Vol 15 ◽  
pp. 155892502094645
Author(s):  
Yao Chu ◽  
Haitao Lin ◽  
Hafsa Jamshaid ◽  
Qi Zhang ◽  
Pibo Ma
Keyword(s):  
Experimental Investigation ◽  
Shear Strength ◽  
Outer Surface ◽  
Shear Force ◽  
Shear Resistance ◽  
Experimental Results ◽  
Shear Properties ◽  
Factors Affecting ◽  
Car Seat ◽  
Seat Cushions

Warp-knitted brush fabrics are composed of an outer surface formed by weaving the front and rear needle beds with spacer yarns interposed between them. Warp-knitted brush fabrics can be used as a non-slip cover for car seat cushions; the adhesion between non-slip fabric and car seat is related to the shear strength of warp-knitted brush fabrics. In this article, to study the factors affecting the shear force of warp-knitted brush fabrics, three different processing methods and four different stretching speed intervals were used to find the effects of stiffeners and action of different speed intervals on shear properties of fabrics. The experimental results show that the stiffener treatment can improve the shear resistance of the warp-knitted brush fabrics, and the effect of different speed intervals can affect the shear resistance of fabrics. These findings will have a guiding significance in the design and production of warp-knitted brush fabrics applied to fabrics such as car seat cushions, and the results can also help to study the shear properties of warp-knitted brush fabrics for wider applications.

scholarly journals Experience of using Odessa region limestones as foundation base

2018 ◽  
Vol 2 (51) ◽  
pp. 85-90
Author(s):  
Vasiliy Mitinskiy ◽  
Oleksandr Novskiy ◽  
Vasiliy Novskiy
Keyword(s):  
Tensile Strength ◽  
Bearing Capacity ◽  
Uniaxial Compression ◽  
Mechanical Characteristics ◽  
Shear Resistance ◽  
Friction Resistance ◽  
Foundation Base ◽  
Bored Piles ◽  
Experimental Values ◽  
Full Scale Tests

The characteristic properties of limestone-shell rock used as foundation base, including shear resistance transformation into friction resistance, are described. The main provisions of the method for determining piles bearing capacity using limestone mechanical characteristics dependence on the tensile strength under uniaxial compression in Odessa region. The results of limestone-shell rock full-scale tests by bored piles are presented. Experimental values of piles bearing capacity are compared with the values obtained by calculation using different methods.

Soil–Geosynthetic Interface Shear in Different Testing Scales

2018 ◽  
Vol 2672 (52) ◽  
pp. 129-141 ◽  
Author(s):  
Gholam H. Roodi ◽  
Amr M. Morsy ◽  
Jorge. G. Zornberg
Keyword(s):  
Large Scale ◽  
Mechanical Performance ◽  
Shear Resistance ◽  
Reinforced Soil ◽  
Small Scale ◽  
Interface Shear ◽  
Shear Model ◽  
Wide Range ◽  
Scale Test ◽  
Large Scale Tests

Geosynthetics have been used to improve mechanical performance of roadway layers (e.g., geosynthetic-reinforced asphalt, geosynthetic-stabilized bases) and a wide range of transportation infrastructures (e.g., geosynthetic-reinforced soil walls). A key aspect in understanding soil–geosynthetic interaction mechanisms involved in each application includes characterization of the interface between geosynthetics and adjacent materials. This study evaluates soil–geosynthetic interface shear in various pullout test scales including standard, smaller than standard, and larger than standard scales. Experimental results obtained from tests conducted in each scale were analyzed to determine the soil–geosynthetic interface shear model. An iteration procedure, similar to that used in t–z analysis of pile loading, was developed to simulate incremental geosynthetic movements. Shape and parameters of the interface shear model were changed to minimize the residual error between experimental and simulated data. It was found that mobilization of the interface shear in the small-scale test differs from that in the standard- and large-scale tests. In the standard- and large-scale tests, the ultimate soil–geosynthetic interface shear mobilized at comparatively small displacements, which could be represented by a linear plastic interface shear model. In the small-scale test, however, the interface shear developed in two phases. A portion of the ultimate interface shear mobilized at comparatively small displacements while additional resistance continued to mobilize at extended displacements. Consequently, the development of interface shear resistance in the standard- and large-scale tests was found to depend on progressive increase of the geosynthetic mobilized length, whereas in the small-scale test the interface shear resistance developed by displacement of the entire geosynthetic.

scholarly journals Bite Force and Influential Factors on Bite Force Measurements: A Literature Review

2010 ◽  
Vol 04 (02) ◽  
pp. 223-232 ◽  
Author(s):  
Duygu Koc ◽  
Arife Dogan ◽  
Bulent Bek
Keyword(s):  
Force Measurement ◽  
Bite Force ◽  
Influential Factors ◽  
Facial Morphology ◽  
Force Measurements ◽  
Physiological Factors ◽  
Technological Advances ◽  
Number Of Factors ◽  
Jaw Biomechanics ◽  
Masticatory System

Maximum voluntary bite force is an indicator of the functional state of the masticatory system and the level of maximum bite force results from the combined action of the jaw elevator muscles modified by jaw biomechanics and reflex mechanisms. The measurement of bite force can provide useful data for the evaluation of jaw muscle function and activity. It is also an adjunctive value in assessing the performance of dentures. Technological advances in signal detection and processing have improved the quality of the information extracted from bite force measurements. However, these measurements are difficult and the reliability of the result depends on a number of factors, such as presence of pain and temporomandibular disorders, gender, age, cranio-facial morphology, and occlusal factors. In addition to these physiological factors, recording devices and techniques are important factors in bite force measurement. Therefore, one should be careful when comparing the bite force values reported in the research. (Eur J Dent 2010;4:223-232)

The Research of Konjac Glucomannan Fracturing System

2013 ◽  
Vol 683 ◽  
pp. 540-543
Author(s):  
Ying Su ◽  
Yi Ding Shen ◽  
Lei Wang ◽  
Xiao Rong Wang ◽  
Xiao Juan Lai ◽  
...  
Keyword(s):  
Shear Rate ◽  
Base Fluid ◽  
Shear Resistance ◽  
Konjac Glucomannan ◽  
Fracturing Fluid

Fracturing fluid was obtained by putting the organic borate and organic titanium crosslinkers into the base fluid of konjac glucomannan. The properties of the fracturing fluid were also discussed. The system was very stable until the temperature reach to 90°C. The system also performed good shear resistance ability when the shear rate was 170s-1 at 80°C for half an hour. The residue content after gel breaking and the suspended sand performance both satisfied the requirements of the operation.

scholarly journals Modelling of stress transfer in root-reinforced soils informed by four-dimensional X-ray computed tomography and digital volume correlation data

2022 ◽  
Vol 478 (2257) ◽  
Author(s):  
Daniel J. Bull ◽  
Joel A. Smethurst ◽  
Gerrit J. Meijer ◽  
I. Sinclair ◽  
Fabrice Pierron ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Shear Zone ◽  
Stress Transfer ◽  
Shear Resistance ◽  
Reinforced Soil ◽  
Analytical Models ◽  
Type Model ◽  
Digital Volume Correlation ◽  
X Ray ◽  
X Ray Computed

Vegetation enhances soil shearing resistance through water uptake and root reinforcement. Analytical models for soils reinforced with roots rely on input parameters that are difficult to measure, leading to widely varying predictions of behaviour. The opaque heterogeneous nature of rooted soils results in complex soil–root interaction mechanisms that cannot easily be quantified. The authors measured, for the first time, the shear resistance and deformations of fallow, willow-rooted and gorse-rooted soils during direct shear using X-ray computed tomography and digital volume correlation. Both species caused an increase in shear zone thickness, both initially and as shear progressed. Shear zone thickness peaked at up to 35 mm, often close to the thickest roots and towards the centre of the column. Root extension during shear was 10–30% less than the tri-linear root profile assumed in a Waldron-type model, owing to root curvature. Root analogues used to explore the root–soil interface behaviour suggested that root lateral branches play an important role in anchoring the roots. The Waldron-type model was modified to incorporate non-uniform shear zone thickness and growth, and accurately predicted the observed, up to sevenfold, increase in shear resistance of root-reinforced soil.

scholarly journals Experimental Investigation and Performance Evaluation of Modified Viscoelastic Surfactant (VES) as a New Thickening Fracturing Fluid

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1470
Author(s):  
Z. H. Chieng ◽  
Mysara Eissa Mohyaldinn ◽  
Anas. M. Hassan ◽  
Hans Bruining
Keyword(s):  
Shear Rate ◽  
Hydraulic Fracturing ◽  
Shear Resistance ◽  
Core Flooding ◽  
Single Chain ◽  
Fracturing Fluid ◽  
The Core ◽  
Core Damage ◽  
Fracturing Fluids ◽  
Viscoelastic Surfactant

In hydraulic fracturing, fracturing fluids are used to create fractures in a hydrocarbon reservoir throughout transported proppant into the fractures. The application of many fields proves that conventional fracturing fluid has the disadvantages of residue(s), which causes serious clogging of the reservoir’s formations and, thus, leads to reduce the permeability in these hydrocarbon reservoirs. The development of clean (and cost-effective) fracturing fluid is a main driver of the hydraulic fracturing process. Presently, viscoelastic surfactant (VES)-fluid is one of the most widely used fracturing fluids in the hydraulic fracturing development of unconventional reservoirs, due to its non-residue(s) characteristics. However, conventional single-chain VES-fluid has a low temperature and shear resistance. In this study, two modified VES-fluid are developed as new thickening fracturing fluids, which consist of more single-chain coupled by hydrotropes (i.e., ionic organic salts) through non-covalent interaction. This new development is achieved by the formulation of mixing long chain cationic surfactant cetyltrimethylammonium bromide (CTAB) with organic acids, which are citric acid (CA) and maleic acid (MA) at a molar ratio of (3:1) and (2:1), respectively. As an innovative approach CTAB and CA are combined to obtain a solution (i.e., CTAB-based VES-fluid) with optimal properties for fracturing and this behaviour of the CTAB-based VES-fluid is experimentally corroborated. A rheometer was used to evaluate the visco-elasticity and shear rate & temperature resistance, while sand-carrying suspension capability was investigated by measuring the settling velocity of the transported proppant in the fluid. Moreover, the gel breaking capability was investigated by determining the viscosity of broken VES-fluid after mixing with ethanol, and the degree of core damage (i.e., permeability performance) caused by VES-fluid was evaluated while using core-flooding test. The experimental results show that, at pH-value ( 6.17 ), 30 (mM) VES-fluid (i.e., CTAB-CA) possesses the highest visco-elasticity as the apparent viscosity at zero shear-rate reached nearly to 10 6 (mPa·s). Moreover, the apparent viscosity of the 30 (mM) CTAB-CA VES-fluid remains 60 (mPa·s) at (90 ∘ C) and 170 (s − 1 ) after shearing for 2-h, indicating that CTAB-CA fluid has excellent temperature and shear resistance. Furthermore, excellent sand suspension and gel breaking ability of 30 (mM) CTAB-CA VES-fluid at 90 ( ∘ C) was shown; as the sand suspension velocity is 1.67 (mm/s) and complete gel breaking was achieved within 2 h after mixing with the ethanol at the ratio of 10:1. The core flooding experiments indicate that the core damage rate caused by the CTAB-CA VES-fluid is ( 7.99 % ), which indicate that it does not cause much damage. Based on the experimental results, it is expected that CTAB-CA VES-fluid under high-temperature will make the proposed new VES-fluid an attractive thickening fracturing fluid.

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