Closure to “Consolidation Coefficient: Cohesive Soil Mixtures”

1965 ◽  
Vol 91 (5) ◽  
pp. 93-94
Author(s):  
Robert L. Kondner ◽  
José R. Vendvell
Keyword(s):  
Cohesive Soil ◽  
Consolidation Coefficient ◽  
Soil Mixtures

Experimental Study on Critical Shear Stress of Cohesive Soils and Soil Mixtures

2021 ◽  
Vol 64 (2) ◽  
pp. 587-600
Author(s):  
Xiaojing Gao ◽  
Qiusheng Wang ◽  
Chongbang Xu ◽  
Ruilin Su
Keyword(s):  
Experimental Data ◽  
Shear Stress ◽  
Critical Shear Stress ◽  
Cohesive Soil ◽  
Future Research ◽  
Cohesive Soils ◽  
List Type ◽  
Soil Mixture ◽  
Linear Relationships ◽  
Soil Mixtures

HighlightsErosion tests were performed to study the critical shear stress of cohesive soils and soil mixtures.Linear relationships were observed between critical shear stress and cohesion of cohesive soils.Mixture critical shear stress relates to noncohesive particle size and cohesive soil erodibility.A formula for calculating the critical shear stress of soil mixtures is proposed and verified.Abstract. The incipient motion of soil is an important engineering property that impacts reservoir sedimentation, stable channel design, river bed degradation, and dam breach. Due to numerous factors influencing the erodibility parameters, the study of critical shear stress (tc) of cohesive soils and soil mixtures is still far from mature. In this study, erosion experiments were conducted to investigate the influence of soil properties on the tc of remolded cohesive soils and cohesive and noncohesive soil mixtures with mud contents varying from 0% to 100% using an erosion function apparatus (EFA). For cohesive soils, direct linear relationships were observed between tc and cohesion (c). The critical shear stress for soil mixture (tcm) erosion increased monotonically with an increase in mud content (pm). The median diameter of noncohesive soil (Ds), the void ratio (e), and the organic content of cohesive soil also influenced tcm. A formula for calculating tcm considering the effect of pm and the tc of noncohesive soil and pure mud was developed. The proposed formula was validated using experimental data from the present and previous research, and it can reproduce the variation of tcm for reconstituted soil mixtures. To use the proposed formula to predict the tcm for artificial engineering problems, experimental erosion tests should be performed. Future research should further test the proposed formula based on additional experimental data. Keywords: Cohesive and noncohesive soil mixture, Critical shear stress, Erodibility, Mud content, Soil property.

Modelling of fibre–cohesive soil mixtures

2013 ◽  
Vol 9 (6) ◽  
pp. 1029-1043 ◽  
Author(s):  
A. Diambra ◽  
E. Ibraim
Keyword(s):  
Cohesive Soil ◽  
Soil Mixtures

Collapse of granular–cohesive soil mixtures on a horizontal plane

2018 ◽  
Vol 15 (3) ◽  
pp. 695-714
Author(s):  
Lorenzo Brezzi ◽  
Fabio Gabrieli ◽  
Simonetta Cola
Keyword(s):  
Horizontal Plane ◽  
Cohesive Soil ◽  
Soil Mixtures

Indexes of reproductive ability and their repeatability in sows of different genotypes, taking into account the polymorphism g.1426g> a of the Mc4r gene

2020 ◽  
pp. 49-62 ◽  
Author(s):  
Viktor Khalak ◽  
Vasyl Voloshchuk ◽  
Konstiantyn Pochernyaev ◽  
Serhii Smyslov ◽  
Maria Ilchenko
Keyword(s):  
Receptor Gene ◽  
Live Weight ◽  
Multiple Births ◽  
Large White ◽  
Mc4r Gene ◽  
Litter Weight ◽  
Reproductive Ability ◽  
Large White Breed ◽  
White Breed ◽  
Consolidation Coefficient

The results of studies of the reproductive ability of sows of different genotypes are given taking into account the polymorphism g.1426G> A of the MC4R gene, the factor of repeatability of characters is determined, and the economic efficiency of the research results is calculated. The experimental part of the research was carried out in the conditions of the «Druzhba-Kaznacheevka» LTD in Dnipropetrovsk region. The objects of research were sows of the Large White breed. It was determined that sows of the main herd, according to signs of reproductive ability, belong to class I and class elite. The experiment showed that sows of genotype AG exceeded their peers of others (GG and AA) in terms of “born piglets total, heads” by 1.6 and 0.7 heads, “Live piglets born (multiple births), heads - by 1 6 and 0.9 heads, “the mass of the litter at the time of birth, kg” - by 2.7 - 1.3 kg., “the mass of the litter at the time of weaning at the age of 28-35 days, kg” - by 5, 1 - 3.9 kg. The difference between animals of the indicated genotypes is: for large-foetus - 0.06-0.01 kg, the index "evenness of the sow’s litter in live weight of piglets at birth, points" - 1.05-1.84 points, index of N. D. Berezovsky - 3.75 -2.36 points. The index of the safety of piglets before weaning ranged from 84.4 to 93.0 %. It was proved that the minimum value of the index “evenness of the sow’s littar in live weight of piglets at the time of birth, points (7.76 ± 1,082 points) are characterized by sows of genotype AA, in which the rate of multiple pregnancy ranged from 8 to 14 pigs, and the value of the sign“ large-foetus, kg "equaled 1.37 kg. The repeatability coefficient for sows of the main herd and sows of the Large White breed of different genotypes for the melanocortin 4 (MC4R) receptor gene ranges from -0.916 ± 0.1418 (І-IV farrow, genotype - GG, sign - “piglet safety before weaning, %) to 0.978 ± 0.0738 (I-V farrow, genotype - GG, sign - “large foetus”, kg ”). The maximum value of the phenotypic consolidation coefficient was found in sows of genotype AA according to the following quantitative characteristics: “live piglets (multiple births), heads.”, “litter weight at the time of birth, kg”, “litter weight at weaning age of 28-35 days, kg "," the safety of piglets before weaning ,% ". The sows of the genotype GG belong to the unconsolidated group according to the signs of reproductive qualities. The use of sows of the genotype for the melanocortin 4 (MC4R) AG receptor gene provides additional products at the level of 5.15 %, and its cost is 165.41 UAH /head. Keywords: sow, breed, reproductive ability, MC4R gene, genotypic consolidation coefficient, variability, correlation, repeatability.

scholarly journals An X-ray CT study of miniature clay sample preparation techniques

2019 ◽  
Vol 92 ◽  
pp. 01004
Author(s):  
Christopher Ibeh ◽  
Matteo Pedrotti ◽  
Alessandro Tarantino ◽  
Rebecca Lunn
Keyword(s):  
Sample Preparation ◽  
Shear Plane ◽  
Cohesive Soil ◽  
Image Resolution ◽  
Particle Orientation ◽  
X Ray ◽  
High Resolution Images ◽  
X Ray Computed ◽  
Sample Disturbance ◽  
Relationship Of

The quality and reliability of cohesive soil laboratory test data can be significantlyaffected by sample disturbance during sampling or sample preparation. Sample disturbance may affect key design and modelling parameters such as stiffness, preconsolidation stress, compressibility and undrained shear strength, and ultimately determine particle mobilization and shear plane development. The use of X-ray computed tomography (X-CT) in the study of soil is restricted by the inverse relationship of specimen size and obtainable image resolution. This has led to the testing of miniature specimen sizes which are far less than conventional laboratory sample size in a bid to obtain high resolution images and detailed particle-scale soil properties; however, these miniature soil specimens are more prone to sample disturbance. In this work 2% muscovite was mixed with speswhite kaolin clay as a strain marker for use in X-CT. The clay soil sample was prepared from slurry and either consolidated using an oedometer or a gypsum mould. Specimens obtained from a 7 mm tube sampler were compared to lathe trimmed specimens with a diameter (Ø) of 7 mm. Results from X-CT imaging were used to study the influence of sampler type on specimen disturbance, by analysing the muscovite particle orientation of the obtained 3D images. The results show that; for samples subjected to large consolidation stress (>200kpa) lathe trimmed specimens may be subject to lesser disturbance compared to tube sampled specimens.

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