scholarly journals Evaluating Biosedimentation for Strength Improvement in Acidic Soil

2021 ◽  
Vol 11 (22) ◽  
pp. 10817
Author(s):  
Ahmed Hassan Saad ◽  
Haslinda Nahazanan ◽  
Zainuddin Bin Md Yusoff ◽  
Muskhazli Mustafa ◽  
Mohamed Hamdy Elseknidy ◽  
...  
Keyword(s):  
Shear Strength ◽  
Large Scale ◽  
Clay Soil ◽  
Soil Improvement ◽  
Physical Models ◽  
Marine Clay ◽  
Soil Medium ◽  
Treated Soil ◽  
The Stability ◽  
Construction Loads

Marine clay soils are problematic soils in the construction industry when they are subjected to construction loads. When these soils are loaded, they lose their structure. This leads to the soil being unable to withstand loads of any magnitude without exhibiting significant, permanent deformations. In order to stabilize the marine soil, new methods for soil improvement were built upon biogrouting by incorporating physical, biological and chemical treatments into the soil. However, the biggest challenge of this method is the bacteria migration through the soil medium. To overcome this issue, the electrokinetic phenomenon can be utilized alongside biogrouting to prevent the bacteria migration. In this regard, the present study applied electrobiogrouting stabilization to investigate the improvement of acidic marine clay soil with a pH of 3.69. To accomplish this, two large-scale physical models with dimensions of 500 × 300 × 1200 mm were fabricated to examine the influence of two different treated distances between the inlet and outlet—450 mm (D45) and 600 mm (D60)—on the stability of the treated soil. It was observed that the shear strength of the treated soil improved significantly. The shear strength at the D45 treated distance increased from 3.65 kPa (untreated soil) to 28.14 kPa (treated soil). However, the strength increased by increasing the treated distance. In addition, compressibility and soil electrical conductivity were reduced significantly, and the Atterberg limits were significantly enhanced from OH to OL. The reasons for the enhancement of treated soil were the formation of CaCO3, which filled the soil voids, and that the water content was reduced. To address issues with marine clay soil, this study aims to minimize the high cost of a special foundation system and the use of non-environmentally friendly materials such as calcium-based binders, aside from the reduction of deformations caused by loading. The findings of this study can be used for acidic soils and the improvement of soil’s geotechnical behavior in general.

scholarly journals Large Scale Laboratory Investigation in the Improvement of Subgrade Characteristics of Clay Soil Stabilized with Construction Demolition Waste

2021 ◽  
Author(s):  
Baki Bagriacik ◽  
Keyword(s):  
Laboratory Investigation ◽  
Large Scale ◽  
Clay Soil ◽  
Soil Improvement ◽  
Economic Life ◽  
Stress Distributions ◽  
Curing Time ◽  
Demolition Waste ◽  
Alternative Method ◽  
Storage Facilities

Earthquakes, are a serious problem for a country where necessary measures should be taken. In this context, buildings that have completed their economic life have been demolished in recent years. A lot of construction demolition waste (CDW) occurred from the destroyed buildings. These wastes were collected in the storage facilities and took up a lot of space. So, it is vital to use these wastes both by emptying the storage facilities and reusing them without harming the nature. An alternative method for re-utilizing these wastes is soil improvement. In this context, the usability of CDW in the improvement of a clay soil was investigated. The bearing bearing ratios (BCR) and stress distributions of the clay soil were examined for different CDW ratios, different improvement depths(H / D) and different curing times. As a result, it was suggested that the optimum CDW ratio should be 14%, the improvement depth should be 1.5 and the optimum curing time should be 14 days in clay soil. The findings obtained from large-scale experiments and microstructure analyzes, it showed that CDW is a waste that can be used in soil improvement.

Effects of Electro Osmotic Consolidation in South West of Johor: Small Laboratory Scale

2014 ◽  
Vol 803 ◽  
pp. 255-264
Author(s):  
Khairul Nizar Mohd Yusof ◽  
Fauziah Ahmad ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Muhammad Faheem Mohd Tahir
Keyword(s):  
Shear Strength ◽  
Water Content ◽  
Clay Soil ◽  
Soft Clay ◽  
Soil Improvement ◽  
Undrained Shear Strength ◽  
Engineering Structures ◽  
Vertical Loading ◽  
South West ◽  
Undrained Shear

Clay soil is one of the problematic soils due to its natural states which have low bearing capacity and high compressibility. The effect and problem of the clay soil characteristic creates a problem for construction especially excessive settlement and this can lead to unstable and potential cracks of engineering structures. At presents, there are few of soil improvement types can be carried out to overcome these problems, and electro osmotic consolidation is one of the options. This method has been applied many years ago especially in european countries. The study encompasses the determination of water content, atterberg’s limits and undrained shear strength after electro osmotic consolidation treatment of clay soils taken from 0.5 m and 1.5 m at southwest part of johor. All the samples were tested according to BS1377:1990. An experimental study was implemented in a pvc cylinder tube having dimensions of 300 mm height and 100 mm diameter. In the results of electro osmotic consolidation tests by installing copper spring electrodes, the measured undrained shear strength was increased considerably at the anodes especially compared to the initial undrained shear strength due to electro osmosis process and consolidation. As laboratory studies of its measurement have shown, the application of electro osmotic consolidation after the application of a direct current applied voltage of 10 volts, at the anodes especially: (i) a decrease by approximately 35% in water content; (ii) an increase around 29% in undrained shear strength; and (iii) a decrease about 21% in index plasticity. The results obtained in this study shows that the electro osmotic enhanced 15 kpa vertical loading consolidation is a feasible approach in strengthening of south west soft clay in johor. It can be clearly suggested that the higher the voltage applied in the system, the higher readings of undrained shear strength and the lower of water content especially at the anodes.

scholarly journals Improvement of Marine Clay Soil Using Lime and Alkaline Activation Stabilized with Inclusion of Treated Coir Fibre

2020 ◽  
Vol 10 (6) ◽  
pp. 2129
Author(s):  
Fatin Amirah Kamaruddin ◽  
Haslinda Nahazanan ◽  
Bujang Kim Huat ◽  
Vivi Anggraini
Keyword(s):  
Soil Stabilization ◽  
Clay Soil ◽  
Positive Impact ◽  
Mechanical Tests ◽  
Soil Reinforcement ◽  
Marine Clay ◽  
Waste Products ◽  
Treated Soil ◽  
Alkaline Activation ◽  
Coir Fibre

Waste products have recently been used as one of the techniques in soil stabilization. The material is not just environmentally friendly, but also cheap. In this study, two different types of soil stabilizer—lime and alkaline activator (AA) with the inclusion of treated coir fibre as soil reinforcement in marine clay soil—were examined. The inclusion of fibre in the treated soil has had a positive impact in increasing the strength of the soil. Therefore, to assess the effectiveness of the soil treatment, mechanical tests such as indirect tensile strength, flexural test and unconfined compressive strength test were performed at three different curing periods (7, 28 and 90 days) on both untreated and treated soil. From the results, the inclusion of fibre in both lime and alkaline activation indicates an enhancement on post-peak behaviour from brittle to more ductile. Microstructural analyses of Field Emission Scanning Electron Microscope (FESEM) and Energy Dispersive X-ray (EDX) were also conducted after shearing to evaluate the changes of the soil before and after the treatment. Overall, results indicate that the treatment transformed the structure of the soil to become denser where it filled the large pores compared to untreated soil.

scholarly journals Analisis Vacuum Consolidation pada Perbaikan Tanah Lempung Lunak dengan Model Axisymmetric (Hal. 68-79)

2018 ◽  
Vol 4 (1) ◽  
pp. 68
Author(s):  
Nadya Utami Rivanga ◽  
Indra Noer Hamdhan
Keyword(s):  
Shear Strength ◽  
Clay Soil ◽  
Soft Soil ◽  
Soft Clay ◽  
Soil Improvement ◽  
Vacuum Consolidation ◽  
Final Project ◽  
Vertical Drain ◽  
Soil Model ◽  
Low Shear

ABSTRAKTanah lempung lunak merupakan jenis tanah yang memiliki kuat geser yang kecil, koefisien permeabilitas yang kecil, kompresibilitas yang besar, dan mempunyai daya dukung rendah. Kondisi tersebut menyebabkan tanah lempung lunak menjadi tantangan pada kontruksi yang akan di bangun diatasnya, sehingga diperlukan perbaikan tanah. Salah satu perbaikan tanah untuk tanah lempung lunak yang banyak dijumpai yaitu vertical drain dan preloading. Pada tugas akhir ini metode tersebut akan dikombinasikan dengan vacuum consolidation. Tegangan vakum yang digunakan pada kasus ini sebesar 50 dan 80 kPa. Analisis yang dilakukan dengan menggunakan program PLAXIS 2D dengan model Axisymmetric. Analisis dilakukan dengan memvariasikan tiga dari sekian banyak soil model yaitu Mohr Coulomb, Hardening Soil, dan Soft Soil. Berdasarkan hasil dari penelitian nilai penurunan, tegangan pori, dan waktu konsolidasi yang dihasilkan berbeda tetapi hasil penurunan soil model dengan Hardening Soil dan Soft Soil tidak terlalu berdeda secara signifikan.Kata Kunci: tanah lempung lunak, vacuum consolidation, Mohr Coulomb, Hardening Soil, Soft Soil, axisymmetric, PLAXIS 2D  ABSTRACTSoft clay is a type of soil that has low shear strength,  high compressibility,  low coeffiecient of permeability and low bearing capacity. The condition caused soft clay soil to be a challenge on the construction that will be built on it, so that it needed soil improvement. The soil improvement for soft clay that often found is vertical drain and preloading. In this final project that method will be combined with vacuum consolidation. The vacuum pressure used in this case amount from 50 and 80 kPa. The analysis was performed using PLAXIS 2D program with Axisymmetric model. The analysis was done by varying the three of soil models Mohr Coulomb, Hardening Soil, and Soft Soil. Based on the settlement of the research, settlement value, pore pressure, and time of consolidation are different but the result of soil models of Hardening Soil and Soft Soil is not significantly differentiated.Keywords: soft clay, vacuum consolidation, Mohr Coulomb, Hardening Soil, Soft Soil, axisymmetric, PLAXIS 2D

Slope Stability Analysis under the Condition of Seepage

2012 ◽  
Vol 204-208 ◽  
pp. 241-245
Author(s):  
Yang Jin
Keyword(s):  
Finite Element Method ◽  
Shear Strength ◽  
Slope Stability ◽  
Negative Impact ◽  
Strength Reduction ◽  
Soil Slope ◽  
Failure State ◽  
Calculation Results ◽  
The Stability ◽  
Shear Strength Reduction

The stability of soil slope under seepage is calculated and analyzed by using finite element method based on the technique of shear strength reduction. When the condition of seepage or not is considered respectively, the critical failure state of slopes and corresponding safety coefficients can be determined by the numerical analysis and calculation. Besides, through analyzing and comparing the calculation results, it shows that seepage has a negative impact on slope stability.

scholarly journals Data-Driven Stability Assessment of Multilayer Long Short-Term Memory Networks

2021 ◽  
Vol 11 (4) ◽  
pp. 1829
Author(s):  
Davide Grande ◽  
Catherine A. Harris ◽  
Giles Thomas ◽  
Enrico Anderlini
Keyword(s):  
Neural Network ◽  
Network Architecture ◽  
Short Term Memory ◽  
Moving Average ◽  
Machine Learning Algorithms ◽  
Physical Models ◽  
Data Driven ◽  
The Stability ◽  
And Control ◽  
Nonlinear Autoregressive

Recurrent Neural Networks (RNNs) are increasingly being used for model identification, forecasting and control. When identifying physical models with unknown mathematical knowledge of the system, Nonlinear AutoRegressive models with eXogenous inputs (NARX) or Nonlinear AutoRegressive Moving-Average models with eXogenous inputs (NARMAX) methods are typically used. In the context of data-driven control, machine learning algorithms are proven to have comparable performances to advanced control techniques, but lack the properties of the traditional stability theory. This paper illustrates a method to prove a posteriori the stability of a generic neural network, showing its application to the state-of-the-art RNN architecture. The presented method relies on identifying the poles associated with the network designed starting from the input/output data. Providing a framework to guarantee the stability of any neural network architecture combined with the generalisability properties and applicability to different fields can significantly broaden their use in dynamic systems modelling and control.

scholarly journals Development and Characterization of Two Types of Surface Displayed Levansucrases for Levan Biosynthesis

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 757
Author(s):  
Huiyi Shang ◽  
Danni Yang ◽  
Dairong Qiao ◽  
Hui Xu ◽  
Yi Cao
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Weight ◽  
Large Scale ◽  
Surface Display ◽  
Yeast Surface Display ◽  
Fusion Partner ◽  
Whole Cell ◽  
Food Industries ◽  
Yeast Surface ◽  
The Stability

Levan has wide applications in chemical, cosmetic, pharmaceutical and food industries. The free levansucrase is usually used in the biosynthesis of levan, but the poor reusability and low stability of free levansucrase have limited its large-scale use. To address this problem, the surface-displayed levansucrase in Saccharomyces cerevisiae were generated and evaluated in this study. The levansucrase from Zymomonas mobilis was displayed on the cell surface of Saccharomyces cerevisiae EBY100 using a various yeast surface display platform. The N-terminal fusion partner is based on a-agglutinin, and the C-terminal one is Flo1p. The yield of levan produced by these two whole-cell biocatalysts reaches 26 g/L and 34 g/L in 24 h, respectively. Meanwhile, the stability of the surface-displayed levansucrases is significantly enhanced. After six reuses, these two biocatalysts retained over 50% and 60% of their initial activities, respectively. Furthermore, the molecular weight and polydispersity test of the products suggested that the whole-cell biocatalyst of levansucrase displayed by Flo1p has more potentials in the production of levan with low molecular weight which is critical in certain applications. In conclusion, our method not only enable the possibility to reuse the enzyme, but also improves the stability of the enzyme.

scholarly journals INTRACISTRONIC MAPPING OF ELECTROPHORETIC SITES IN DROSOPHILA MELANOGASTER: FIDELITY OF INFORMATION TRANSFER BY GENE CONVERSION

Genetics ◽  
1974 ◽  
Vol 76 (2) ◽  
pp. 289-299
Author(s):  
Margaret McCarron ◽  
William Gelbart ◽  
Arthur Chovnick
Keyword(s):  
Drosophila Melanogaster ◽  
Information Transfer ◽  
Large Scale ◽  
Genetic Basis ◽  
Xanthine Dehydrogenase ◽  
Specific Protein ◽  
Wild Type ◽  
Electrophoretic Variation ◽  
The Stability ◽  
Recombination Experiments

ABSTRACT A convenient method is described for the intracistronic mapping of genetic sites responsible for electrophoretic variation of a specific protein in Drosophila melanogaster. A number of wild-type isoalleles of the rosy locus have been isolated which are associated with the production of electrophoretically distinguishable xanthine dehydrogenases. Large-scale recombination experiments were carried out involving null enzyme mutants induced on electrophoretically distinct wild-type isoalleles, the genetic basis for which is followed as a nonselective marker in the cross. Additionally, a large-scale recombination experiment was carried out involving null enzyme rosy mutants induced on the same wild-type isoallele. Examination of the electrophoretic character of crossover and convertant products recovered from the latter experiment revealed that all exhibited the same parental electrophoretic character. In addition to documenting the stability of the xanthine dehydrogenase electrophoretic character, this observation argues against a special mutagenesis hypothesis to explain conversions resulting from allele recombination studies.

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