scholarly journals Numerical Analysis on Performance of the Middle-Pressure Jet Grouting Method for Ground Improvement

Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 313
Author(s):  
Shinya Inazumi ◽  
Sudip Shakya ◽  
Takahiro Komaki ◽  
Yasuharu Nakanishi
Keyword(s):  
Life Cycle ◽  
Comparative Analysis ◽  
Ground Improvement ◽  
Cement Slurry ◽  
Mechanical Agitation ◽  
High Quality ◽  
Jet Grouting ◽  
Computer Aided ◽  
Improvement Method ◽  
Cae System

This study focused on the middle-pressure jet grouting method, which has a complicated development mechanism for the columnar soil-improved body, with the aim of establishing a computer-aided engineering (CAE) system that can simulate the performance on a computer. Furthermore, in order to confirm the effect of middle-pressure jet grouting with mechanical agitation and mixing, a comparative analysis was performed with different jet pressures, the development situation was visualized, and the performance of this method was evaluated. The results of MPS-CAE as one of the CAE systems showed that the cement slurry jet ratio in the planned improvement range, including the periphery of the mixing blade, by the middle-pressure jet grouting together with the mechanical agitation and mixing was increased and a high quality columnar soil-improved body was obtained. It is expected that the introduction of CAE will contribute to the visualization of the ground, and that CAE will be an effective tool for the visual management of construction for ground improvement and the maintenance of improved grounds during the life cycle of the ground-improvement method.

scholarly journals Performance of mechanical agitation type of ground-improvement by CAE system using 3-D DEM

2020 ◽  
Vol 6 ◽  
pp. 100108 ◽  
Author(s):  
Shinya Inazumi ◽  
Apiniti Jotisankasa ◽  
Koki Nakao ◽  
Susit Chaiprakaikeow
Keyword(s):  
Ground Improvement ◽  
Mechanical Agitation ◽  
Cae System

Zophobas atratus (Fabricius, 1775) – new genus and species of darkling beetles (Coleoptera, Tenebrionidae) for the fauna of Ukraine

2018 ◽  
Vol 14 (1) ◽  
pp. 10-24
Author(s):  
V. N. Fursov ◽  
L. S. Cherney
Keyword(s):  
Life Cycle ◽  
Comparative Analysis ◽  
Sexual Dimorphism ◽  
Antennal Segment ◽  
Laboratory Culture ◽  
Important Species ◽  
Darkling Beetles ◽  
Zophobas Atratus ◽  
Sensory Zone ◽  
Coleoptera Tenebrionidae

Darkling beetle Zophobas atratus (Coleoptera, Tenebrionidae) is recorded here for the first time as a new species for the fauna of Ukraine. Detailed study on morphology of preimaginal stages and biology of this species recently introduced to Ukraine, is given here. Zophobas atratus is an important species being easily reared in laboratory cultures and widely distributed in North and South America, Europe, and Asia. Detailed descriptions of all life stages, including egg, young and older larvae, pupa and adult of Z. atratus are required for further taxonomical study of the genus Zophobas, which isn’t yet definitively established. New identification keys for adults and larvae of the genera of tribe Tenebrionini are presented here, based on a comparative analysis of the taxonomic characters of adults and larvae of Z. atratus and species from the genera Tenebrio and Neatus. Comparative analysis of morphology of larva of Z. atratus and larvae of the tribe Cteniopodini of close subfamily Alleculinae was conducted here. The subfamily Alleculinae previously had the rank of family Alleculidae, but our analysis confirmed the reliability of its current taxonomic position as subfamily. The study of morphology of larvae of 1st and 2nd instars of Z. atratus revealed that they are characterized by special taxonomic structures that are not characteristic for oldest instars of larvae of Z. atratus. These characters include absence of spines on caudal segment, presence of a set of 4 setae at posterior margin of tergites of prothorax, metathorax, and 1st to 8th abdominal segments, strongly convex 2nd antennal segment and sensory zone in the form of an open ring on its apex, and etc. Moreover, structure of antenna of larvae of Z. atratus is similar to that of oldest larvae of most species of darkling beetles of the fauna of Ukraine. The most distinctive features of Z. atratus are: sexual dimorphism in structure of clypeus of adults; filiform sclerotized antenna of larva with a continuous sensory zone at apex of 2nd segment, weakly developed 3rd segment; fusion of sclerotized pleurites of 1st–8th abdominal segments with their tergites; sexual dimorphism in structure of 9th abdominal segment of pupa, and presence of two hooks on apex of its appendages. The data of original study of features of life cycle of Z. atratus are given. The pictures and photos of details of morphology of egg, larvae, pupa and adult of Z. atratus are presented. It was recored that life cycle of Z. atratus from laying of egg to the emergence of adult continues from 169 up to 181 days. Adults lived maximum up to 206 days. Maturation of eggs in female after copulation continues 10-11 days. Stage of egg continues 7 days, larva – up to 151 days, including pre-pupal period from 6 to 22 days, pupa – from 8 to 21 days. Twelve larval stages of Z. atratus were recorded in laboratory culture.

Qualitative anatomical restoration of the contact point of teeth – prevention of localized forms of periodontal diseases

2020 ◽  
Vol 25 (1) ◽  
pp. 10-15
Author(s):  
L. Yu. Orekhova ◽  
O. V. Prokhorova ◽  
V. Yu. Shefov
Keyword(s):  
Comparative Analysis ◽  
Computer Simulations ◽  
Periodontal Diseases ◽  
Contact Point ◽  
Clinical Stage ◽  
High Quality ◽  
Cross Sectional ◽  
Clinical Stages ◽  
Anatomical Restoration ◽  
Approximal Surfaces

Relevance. The restoration of a high-quality anatomical and functional contact point of teeth plays an important role in preventing the development of localized forms of periodontal disease.Purpose. Development of recommendations for qualitative anatomical restoration of the contact point of teeth for the prevention of localized forms of periodontal diseases.Materials and methods. In our study, which consisted of pre-clinical and clinical stages, were analyzed 50 CT scan of the chewing group teeth calculated the ratio of approximal surfaces of molars and premolars to the width of their crowns and computer simulations of the results of restoration of contact point. We also conducted a comparative analysis of wedges of different material with different cross-sectional shapes. At the clinical stage, the restoration of the contact point of teeth in patients according to our recommendations was carried out.Results. On the basis of the data obtained during the study, a formula for calculating the height and size of the restored contact point was compiled. Recommendations for anatomical restoration of the contact point are formulated.Conclusion. The application of the recommendations developed by us allows anatomically qualitatively restore the contact point and prevent the development of localized periodontal diseases.

scholarly journals Visual evaluation of relative deep mixing method type of ground-improvement method

2021 ◽  
pp. 100233
Author(s):  
Koki Nakao ◽  
Shinya Inazumi ◽  
Toshiaki Takaue ◽  
Shigeaki Tanaka ◽  
Takayuki Shinoi
Keyword(s):  
Ground Improvement ◽  
Visual Evaluation ◽  
Deep Mixing ◽  
Improvement Method ◽  
Mixing Method

Uplift and Settlement Prediction Model of Marine Clay Soil e Integrated with Polyurethane Foam

2019 ◽  
Vol 9 (1) ◽  
pp. 481-489
Author(s):  
D.C. Lat ◽  
I.B.M. Jais ◽  
N. Ali ◽  
B. Baharom ◽  
N.Z. Mohd Yunus ◽  
...  
Keyword(s):  
Polyurethane Foam ◽  
Clay Soil ◽  
Ground Improvement ◽  
Soft Soil ◽  
Soft Clay ◽  
Effective Thickness ◽  
Marine Clay ◽  
Uplift Pressure ◽  
Pu Foam ◽  
Improvement Method

AbstractPolyurethane (PU) foam is a lightweight material that can be used efficiently as a ground improvement method in solving excessive and differential settlement of soil foundation mainly for infrastructures such as road, highway and parking spaces. The ground improvement method is done by excavation and removal of soft soil at shallow depth and replacement with lightweight PU foam slab. This study is done to simulate the model of marine clay soil integrated with polyurethane foam using finite element method (FEM) PLAXIS 2D for prediction of settlement behavior and uplift effect due to polyurethane foam mitigation method. Model of soft clay foundation stabilized with PU foam slab with variation in thickness and overburden loads were analyzed. Results from FEM exhibited the same trend as the results of the analytical method whereby PU foam has successfully reduced the amount of settlement significantly. With the increase in PU foam thickness, the settlement is reduced, nonetheless the uplift pressure starts to increase beyond the line of effective thickness. PU foam design chart has been produced for practical application in order to adopt the effective thickness of PU foam within tolerable settlement value and uplift pressure with respect to different overburden loads for ground improvement works.

ELEMENT-FREE METHODS VS. MESH-LESS CAE

2006 ◽  
Vol 03 (04) ◽  
pp. 445-464 ◽  
Author(s):  
HIDEYUKI SAKURAI
Keyword(s):  
Mesh Generation ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Generation Task ◽  
3D Objects ◽  
Computer Aided ◽  
Analysis System ◽  
Mesh Less ◽  
Element Free ◽  
Cae System

Element-free methods (EFreeMs) are expected to eliminate the mesh generation task. However, a computer aided engineering (CAE) system by EFreeM for complex three-dimensional (3D) objects has not yet been developed. This paper discusses the obstacles to the CAE and way to solve them. A 3D groundwater flow analysis system with an EFreeM is presented as a practical CAE. In the system, instead of pursuing mesh-less CAE, a unique mesh is employed to achieve the practical CAE. Some 3D examples show the performance and usefulness of the system. Two serious drawbacks of the EFreeM are also discussed from the viewpoint of the practical CAE.

Project Implementation Decision Using Software Development Life Cycle Models: A Comparative Approach

2021 ◽  
Vol 28 (1) ◽  
Author(s):  
M.A. Adeagbo ◽  
J.E.T. Akinsola ◽  
A.A. Awoseyi ◽  
F. Kasali
Keyword(s):  
Life Cycle ◽  
Comparative Analysis ◽  
Software Development ◽  
Cost Estimation ◽  
Comparative Approach ◽  
Project Implementation ◽  
Development Life Cycle ◽  
Software Development Life Cycle ◽  
Waterfall Model ◽  
Spiral Model

Selection of a suitable Software Development Life Cycle (SDLC) model for project implementation is somewhat confusing as there are a lot of SDLC models with similar strengths and weaknesses. Also, the solutions proffered among the researchers so far have been the  qualitative comparative analysis of SDLC models. Hence, this paper proposes a comparative analysis of SDLC models using quantitative approach in relation to strengths and weaknesses of SDLC models. The study adapted comparative analysis and Software Development Life Cycle (SDLC) models features’ classification using ten characteristics such as project complexity, project size, project duration, project with risk, implementation/initial cost, error discovery, associated cost, risk analysis, maintenance and cost estimation. A quantitative measure that employs online survey using experts in software design and engineering, project management and system analysis was carried out for the evaluation of SDLC models. Purposeful Stratified Random Sampling (SRS) technique was used to gather the data for analysis using XLSTAT after pre-processing, taking into consideration both benefit and cost criteria. The overall performance evaluation showed that Spiral-Model is the best followed by V-Model and lastly Waterfall Model with comparative values of 38.63%, 35.76% and 25.61% respectively. As regards cost estimation, Waterfall Model is the most efficient with value of 41%, then V-Model with 31% and lastly Spiral Model with 28%. V-Model has great error recovery capability with value of 45% which is closely followed by Spiral Model with 37% and lastly Waterfall Model with 18%. The study revealed that, a model with efficient risk assurance does not guarantee efficient cost management. In the future work, more characteristics regarding SDLC models shall be considered.

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