scholarly journals State-of-the-Art-Review of Collapsible Soils

2000 ◽  
Vol 5 ◽  
pp. 115 ◽  
Author(s):  
A. A. AL-Rawas
Keyword(s):  
Field Tests ◽  
Clay Content ◽  
Field Testing ◽  
Dry Density ◽  
Foundation Design ◽  
Treatment Methods ◽  
Collapse Potential ◽  
Collapsible Soils ◽  
Different Types ◽  
Compaction Control

Collapsible soils are encountered in arid and semi-arid regions. Such soils cause potential construction problems due to their collapse upon wetting. The collapse phenomenon is primarily related to the open structure of the soil. Several soil collapse classifications based on parameters such as moisture content, dry density, Atterberg limits and clay content have been proposed in the literature as indicators of the soil collapse potential. Direct measurement of the magnitude of collapse, using laboratory and/or field tests, is essential once a soil showed indications of collapse potential. Treatment methods such as soil replacement, compaction control and chemical stabilization showed significant reduction in the settlement of collapsible soils. The design of foundations on collapsible soils depends on the depth of the soil, magnitude of collapse and economics of the design. Strip foundations are commonly used when collapsing soil extends to a shallow depth while piles and drilled piers are recommended in cases where the soil extends to several meters. This paper provides a comprehensive review of collapsible soils. These include the different types of collapsible soils, mechanisms of collapse, identification and classification methods, laboratory and field testing, treatment methods and guidelines for foundation design.

Predicting Collapse Potential of Soils with Neural Networks

1997 ◽  
Vol 1582 (1) ◽  
pp. 22-28 ◽  
Author(s):  
C. H. Juang ◽  
David J. Elton
Keyword(s):  
Neural Networks ◽  
Network Models ◽  
Field Testing ◽  
Network Architectures ◽  
Training Algorithms ◽  
Index Properties ◽  
Neural Network Models ◽  
Collapse Potential ◽  
Collapsible Soils ◽  
And Training

Collapsible soils are known to experience a dramatic decrease in volume upon wetting. This can be very detrimental to structures founded on collapsible soils. Whereas field testing might be the most reliable way to determine collapse potential, the engineer often sees it as the last resort. Neural network models for predicting the collapse potential of soils on the basis of basic index properties are presented. Field data, consisting of index properties and collapse potential, are used to train and test neural networks. Various network architectures and training algorithms are examined and compared. The trained networks are shown to be able to identify the collapsible soils and predict the collapse potential.

Driving in the Dust: Challenges and Lessons Learned from Field Testing in Degraded Visual Environments

2020 ◽  
Vol 64 (1) ◽  
pp. 1916-1920
Author(s):  
Kayla L. Riegner ◽  
Kelly S. Steelman
Keyword(s):  
Research Program ◽  
Field Tests ◽  
Field Testing ◽  
Driving Performance ◽  
Lessons Learned ◽  
Current Paper ◽  
Ground Vehicle ◽  
Significant Safety ◽  
Dust Clouds

Degraded visual environments (DVEs) pose significant safety and efficiency problems in military ground vehicle operations. As part of a larger research program, two field tests were conducted to evaluate driving aids while indirect driving in DVEs. The current paper presents the results of one of these field tests, and focuses on the challenges and lessons learned in designing a challenging test course and producing consistent dust clouds for assessing Soldier driving performance and workload in degraded visual environments.

Effect of Nano Clay on Mechanical Behavior of Bamboo Fiber Reinforced Polyester Composites

2018 ◽  
Vol 877 ◽  
pp. 294-298 ◽  
Author(s):  
Kundan Patel ◽  
Jay Patel ◽  
Piyush Gohil ◽  
Vijaykumar Chaudhary
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Clay Content ◽  
Weight Fraction ◽  
Industrial Applications ◽  
Vital Role ◽  
Bamboo Fiber ◽  
Nano Clay ◽  
Different Types ◽  
Polyester Composite

Composite materials play a vital role in many industrial applications. Researchers are working on fabrication of new composite materials worldwide to enhance the applicability of these materials. The present study aimed to investigate the effect of Nano clay loading as filler on the mechanical properties of the bamboo fiber yarn reinforced polyester composite. Five different types of composite specimen were prepared with Nano clay loadings of 0 to 4 % weight fraction using hand lay-up technique. It was observed that the composite sheet with 1 wt % nano clay content exhibited the optimized tensile and flexural strength. However the mechanical properties tend to decrease with addition of nano clay content from 2 to 4 wt %. In spite of that the values of mechanical properties with 2 and 3 wt % nano clay content is higher than 0 wt % nano clay content.

scholarly journals Screening of the Argentinean INTA peanut core collection with a molecular marker associated with resistance to Sclerotinia minor Jaggar

2020 ◽  
Vol 47 (1) ◽  
pp. 9-16
Author(s):  
K.D. Chamberlin ◽  
J.J. Baldessari ◽  
E.M.C. Mamani ◽  
M.V. Moreno
Keyword(s):  
Molecular Marker ◽  
Core Collection ◽  
Field Tests ◽  
Field Testing ◽  
Blight Resistance ◽  
Phenotypic Traits ◽  
Sources Of Resistance ◽  
Sclerotinia Minor ◽  
Sclerotinia Blight ◽  
Potential Sources

ABSTRACT Cultivated peanut, the third most important oilseed in the world, is consistently threatened by various diseases and pests. Sclerotinia minor Jagger (S. minor), the causal agent of Sclerotinia blight, is a major threat to peanut production in many countries and can reduce yield by up to 50% in severely infested fields. Host plant resistance will provide the most effective solution to managing Sclerotinia blight, but limited sources of resistance to the disease are available for use in breeding programs. Peanut germplasm collections are available for exploration and identification of new sources of resistance, but traditionally the process is lengthy, requiring years of field testing before those potential sources can be identified. Molecular markers associated with phenotypic traits can speed up the screening of germplasm accessions. The objective of this study was to genotype the peanut core collection of the Instituto Nacional de Tecnología Agropecuaria (INTA) Manfredi, Argentina, with a molecular marker associated with Sclerotinia blight resistance. One hundred and fifty-four (154) accessions from the collection were available and genotyped using the Simple Sequence Repeat (SSR) marker. Accessions from each botanical variety type represented in the core collection were identified as new potential sources of resistance and targeted for further evaluation in field tests for Sclerotinia blight resistance.

scholarly journals Geoelectric method applied in correlation between physical characteristics and electrical properties of the soil

2017 ◽  
Vol 2 (2) ◽  
pp. 37 ◽  
Author(s):  
Antonio Marcelino Silva Filho ◽  
Carlos Leandro Borges Silva ◽  
Marco Antonio Assfalk Oliveira ◽  
Thyago Gumeratto Pires ◽  
Aylton José Alves ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Soil Moisture ◽  
Electrical Properties ◽  
Moisture Content ◽  
Soil Compaction ◽  
Clay Content ◽  
Physical Characteristics ◽  
Soil Dynamics ◽  
Different Types ◽  
The Relationship

This paper presents the study of the relationship between electrical properties and physical characteristics of the soil. Measures of apparent electrical resistivity of the soil were made for different types of soil, varying moisture content gradually while maintaining a constant compaction, and then varying the compaction and relating it to a constant humidity. Development of a correlation surface is proposed in order to identify granulometry of the soil from moisture and compaction measurements. For the study of spatial variability, two areas were chosen to allow the change of moisture content and compaction in order to verify the measurement capacity of apparent electrical resistivity of the soil as methodology to identify change in soil dynamics. Results obtained show correlations among apparent electrical resistivity of the soil, moisture, soil compaction and clay content.

scholarly journals Researched the wear resistance of hardened plowshares by electroarc and spot welding

2019 ◽  
pp. 189-196
Author(s):  
M. Vаsylenko ◽  
D. Buslаiev ◽  
O. Kаlinin ◽  
Yu. Kononogov
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Spot Welding ◽  
Field Tests ◽  
Sandy Soils ◽  
Clay Soils ◽  
Basic Principles ◽  
Data Field ◽  
Different Types ◽  
Analytical Processing

Purpose. The researched of the wear resistance of hardened plowshares by electroarc and abrasion-resistant electrodes, when they are used in soils of different types. Methods. Conducting and planning an experiment, mathematical statistics and analytical processing of experimental data, field tests of experimental plowshares using the basic principles of the theory of friction and abrasive wear. Results. The characteristic defects of shares operating in different types of soils are determined. According to the proposed hardening technology, the wear rate of experimental shares is reduced. Conclusions 1.It has been established that the nature of the parts of tillage machines wear is significantly different when operating on various types of soils. 2.It was found that the wear rate of hardened plowshares for sandy soils is 1.2–1.6 times less than that of serial parts; hardened plowshares for clay soils also have a wear rate of 1.2–1.3 times less than serial ones. Keywords: exploitation, hardfacing, plowshares, soils of different types, wear, wear resistance.

The importance of aerodynamics for prosthetic limb design used by competitive cyclists with an amputation: An introduction

2014 ◽  
Vol 39 (3) ◽  
pp. 232-237 ◽  
Author(s):  
Bryce Dyer
Keyword(s):  
Field Test ◽  
Aerodynamic Drag ◽  
Field Tests ◽  
Field Testing ◽  
Test Method ◽  
Limb Amputation ◽  
Small Scale ◽  
Prosthetic Limb ◽  
Testing Method ◽  
Competitive Cyclists

Background/Objectives: This study introduces the importance of the aerodynamics to prosthetic limb design for athletes with either a lower-limb or upper-limb amputation. Study design: The study comprises two elements: 1) An initial experiment investigating the stability of outdoor velodrome-based field tests, and 2) An experiment evaluating the application of outdoor velodrome aerodynamic field tests to detect small-scale changes in aerodynamic drag respective of prosthetic limb componentry changes. Methods: An outdoor field-testing method is used to detect small and repeatable changes in the aerodynamic drag of an able-bodied cyclist. These changes were made at levels typical of alterations in prosthetic componentry. The field-based test method of assessment is used at a smaller level of resolution than previously reported. Results: With a carefully applied protocol, the field test method proved to be statistically stable. The results of the field test experiments demonstrate a noticeable change in overall athlete performance. Aerodynamic refinement of artificial limbs is worthwhile for athletes looking to maximise their competitive performance. Conclusion: A field-testing method illustrates the importance of the aerodynamic optimisation of prosthetic limb components. The field-testing protocol undertaken in this study gives an accessible and affordable means of doing so by prosthetists and sports engineers. Clinical relevance Using simple and accessible field-testing methods, this exploratory experiment demonstrates how small changes to riders’ equipment, consummate of the scale of a small change in prosthetics componentry, can affect the performance of an athlete. Prosthetists should consider such opportunities for performance enhancement when possible.

STATIC AND DYNAMIC PERFORMANCE EVALUATION OF A PRE-STRESSED CONCRETE BRIDGE THROUGH FIELD TESTING AND MONITORING

2009 ◽  
Vol 09 (04) ◽  
pp. 711-728 ◽  
Author(s):  
C. S. CAI ◽  
M. ARAUJO ◽  
A. NAIR ◽  
X. SHI
Keyword(s):  
Quantitative Methods ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Field Tests ◽  
Field Measurements ◽  
Field Testing ◽  
Concrete Bridge ◽  
Bridge Structures ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

This paper presents field tests performed on a slab-on-girder pre-stressed concrete bridge. The bridge was tested under static loading, crawling loading, and dynamic loading. A full three-dimensional finite element prediction under both static and dynamic loadings was carried out and the results were compared with the field measurements. While acoustic emission (AE) monitoring of bridge structures is not a new vista, the method has not been fully exploited in bridge monitoring. Though numerous quantitative methods have been proposed, they have not yet developed to be useful for actual field tests of bridges. Therefore, in this study, an attempt was made to use the intensity analysis technique for damage quantification using the AE method.

Communications-Based Train Control: Test Program Challenges

2018 ◽  
Author(s):  
Kenneth Diemunsch ◽  
Keith Altamirano
Keyword(s):  
Field Tests ◽  
Field Testing ◽  
Smooth Transition ◽  
Testing Time ◽  
Acceptance Test ◽  
Test Program ◽  
Root Cause ◽  
Train Control ◽  
Transit Agencies ◽  
Program Challenges

This paper discusses two real-world challenges faced by Communications-Based Train Control (CBTC) testing programs. a) Why is it that even after a successful complete system Factory Acceptance Test (FAT), the performance of the CBTC system during the first few months of field tests is prone to frequent failures? On some projects, it may be months between a successful FAT and the first operation in CBTC mode. b) How accurately and efficiently can the root cause of failures during the field tests be identified and how could a test program be improved to have a smooth transition from field testing to revenue service. Unlike commissioning a conventional signaling system, where after circuit break down and operation testing are completed, the system works well during revenue service, CBTC projects experience an additional round of ‘surprises’ when the system is put in service after months or years of testing [1]. This comment is valid for both new lines and signaling upgrade projects, it should be noted that signaling upgrade projects are more prone to ‘surprises’ due to the limited track access which reduces testing time. Even though the final test results prior to revenue service indicate no ‘showstoppers’, once system is placed in service, it is common to unearth major issues that impact sustainable revenue operation. Though, as it should, this often comes as a surprise to transit agencies installing CBTC for the first time, it is almost accepted as fate by most of the experienced CBTC engineers. This paper describes the tests performed prior to placing system in revenue service and analyzes some of the issues experienced. Detailed information regarding the field tests can be found in [2]. Description of possible mitigations used by CBTC suppliers and transit agencies are included, as well as likely reasons for such a predictable pattern on CBTC projects. Finally, ideas about how to continue improving the mitigation to minimize the risk of major system issues are presented.

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