Flow limit and compaction characteristic of some problematic soils

Expansive soils are problematic soils for Civil Engineers. Black cotton (BC) soils possess low strength and high compressibility, due to these properties black cotton soils are considered to be challenging one for analysis. To achieve desired properties of soil for construction purpose these black cotton soil must be enhanced to meet its requirement. To modify the properties of black cotton soils, many treatment methods are there. In this paper an attempt has been made to improve the properties of black cotton soil by using industrial waste through stabilization method. By stabilizing the soil properties are enhanced and make it suitable for subgrade construction. In this work, the combined effect of Lime and Phosphogypsum (PG) on compaction characteristics, Atterberg’s Limit, Unconfined Compressive Strength (UCS) for original soil, California Bearing Ratio (CBR) and direct shear Test of a black cotton soil with percentage varying of Lime and Phosphogypsum was carried out. The soil samples were tested for tri-axial compression test and CBR tests were carried out after 4 days curing period. From the results, it has been inferred that the black cotton soil treated with Lime and Phosphogypsum in the percentages of (4:4) has better strength characteristics. Hence, it may be concluded that Lime and Phosphogypsum can be used for stabilization of black cotton soils for pavement subgrade

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Systematic approach to assessing the applicability of fly-ash-based geopolymer for clay stabilization

Canadian Geotechnical Journal ◽

10.1139/cgj-2019-0215 ◽

2020 ◽

Vol 57 (9) ◽

pp. 1356-1368 ◽

Cited By ~ 1

Author(s):

Hayder H. Abdullah ◽

Mohamed A. Shahin ◽

Megan L. Walske ◽

Ali Karrech

Keyword(s):

Fly Ash ◽

Systematic Approach ◽

Soil Stabilization ◽

Ground Improvement ◽

Experimental Program ◽

Attractive Alternative ◽

Chemical Additives ◽

Soil Mineralogy ◽

Problematic Soils ◽

Ph Level

Traditional soil stabilization by chemical additives such as cement and lime is a well-established technique for ground improvement of problematic soils. However, with the advantage of lower carbon emission and energy consumption, fly-ash-based geopolymer has recently become an attractive alternative to traditional stabilizers. Nevertheless, the literature lacks systemic approaches that assist engineers to apply this promising binder for soil stabilization, including the proper dosages required for an effective treatment. This paper introduces a systematic approach to assess the applicability of fly-ash-based geopolymer for stabilization of clay soils, through a comprehensive experimental program where engineered and natural clays were examined and evaluated, including soil compaction, plasticity, compressive strength, durability, pH level, and impact of pulverization. The results revealed several factors that influence the level of enhancement of geopolymer-treated clays, including the soil mineralogy, plasticity–activity properties, geopolymer concentration, curing time, and pulverization.

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Does Cerebral Blood Flow Limit Maximal Aerobic Power Output?

Medicine & Science in Sports & Exercise ◽

10.1249/01.mss.0000402920.14578.55 ◽

2011 ◽

Vol 43 (Suppl 1) ◽

pp. 82

Author(s):

Andrew W. Subudhi ◽

J Tod Olin ◽

Andrew C. Dimmen ◽

Bengt Kayser ◽

Robert C. Roach

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Power Output ◽

Aerobic Power ◽

Maximal Aerobic Power ◽

Flow Limit ◽

Aerobic Power Output

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Performance of electrokinetic treatment of fine-grained problematic soils

Journal of Engineering Research ◽

10.36909/jer.8785 ◽

2021 ◽

Vol 9 (4B) ◽

Author(s):

Abiola Ayopo Abiodun ◽

◽

Zalihe Nalbantoglu ◽

Keyword(s):

Low Voltage ◽

Soil Depth ◽

Experimental Tests ◽

Interactive Effects ◽

Engineering Properties ◽

Laboratory Model ◽

Fine Grained ◽

Electrode Length ◽

Problematic Soils

Electrokinetic (EK) treatment is an innovative, cost-effective in situ ground modification technology. The EK treatment uses a combination of low-voltage direct-current, electrodes, and ionic solutions across problematic soil to improve the ground conditions. This study aims to model the effect of changing electrode length (le) on the performance of the EK treatment on the engineering properties of fine-grained problematic soils. The consideration of the changing electrode lengths (le), varying soil depths (ds), and lengthwise anode to cathode distances (dA↔E), in the soil block samples, is in the form of the laboratory model test tank. The significant performance of the experimental tests was with changing electrode lengths of 0.25le (7.5 cm), 0.50le (15.0 cm), 0.75le (22.5 cm), and 1.0le (30.0 cm). The study analyzed the test data obtained from the Atterberg limit and one-dimensional swelling tests at different extraction points of the EK treated soils in the test tanks. Furthermore, the study carefully analyzed the effect of changing electrode length (le) on the performance of the EK treatment. The results of the Design of Experiment (DOE) model analysis revealed that the effect of changing electrode length (le) on the plasticity index (PI), and swelling potential (SP) of the EK treated soils, was significant. For a specific soil depth (ds), the electrode lengths (le) of 0.50le and 0.75le were significantly effective in reducing the PI, and the SP of the EK treated soils. Unlike other studies in the literature, the use of DOE analysis in the present study enabled the detection of the significant input factors and their interactive effects on the PI and the SP, thus, enabling the practicing engineers to navigate accurate design models for large in situ applications.

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Experimental and field verifications of radial gates as flow measurement structures

Water Science & Technology Water Supply ◽

10.2166/ws.2021.071 ◽

2021 ◽

Author(s):

Hossein Khalili Shayan ◽

Javad Farhoudi ◽

Alireza Vatankhah

Keyword(s):

Field Measurements ◽

The United States ◽

Data Series ◽

Flow Conditions ◽

Flow Limit ◽

Before And After ◽

Energy And Momentum ◽

Extensive Experimental Data ◽

Radial Gate ◽

Discharge Curves

Abstract Radial gates are common structures in irrigation projects. This paper presents some theoretical-based equations for explicit estimation of the discharge from the radial gate under free and submerged flow conditions using Energy and Momentum (E-M) principles. The proposed equations were calibrated using extensive experimental data collected from the literature and this study for three types of radial gates under free and submerged flow conditions. The submergence threshold of radial gates is concluded, based on the concepts of hydraulic jump and the intersection of free and submerged head-discharge curves. The results indicated that the error in estimating the discharge increases under transition ( − 2.5 ≤ Sr% ≤ + 2.5), gate lip (1 < y0/w ≤ 2), and high submerged (yt/y0 ≥ 0.95) flow conditions. However, in these flow limit conditions, the discharge error can be considerably decreased by adjusting the tailwater depth to flow depth just after the gate and using the energy equation for the sections before and after the gate. The efficiency of the proposed methods was evaluated based on the data series from field measurements of radial gates in 29 check structures at irrigation canals in the United States and Iran. The results showed that the discharge could be estimated using the proposed equations in field conditions with acceptable accuracy.

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An Experimental Study on the Effect of Tire Powder on the Geotechnical Properties of Clay Soils

Civil Engineering Journal ◽

10.28991/cej-0309118 ◽

2018 ◽

Vol 4 (3) ◽

pp. 594 ◽

Cited By ~ 6

Author(s):

Davood Akbarimehr ◽

Esmael Aflaki

Keyword(s):

Clay Soil ◽

Geotechnical Properties ◽

Atterberg Limits ◽

Clay Soils ◽

Positive Effects ◽

Advantages And Disadvantages ◽

Different Types ◽

Problematic Soils ◽

Geotechnical Problems ◽

Comprehensive Study

With respect to the increasing production of tire wastes, the use of these wastes as an additive in civil engineering has always gained attentions of researchers due to their positive effects on material properties and reduction of environmental problems. Clay soils, as problematic soils, have always caused geotechnical problems including high Atterberg limits and consequently low workability. Tire powder, as one of the products of tire wastes, lacks clay cohesion and it can be effective in altering the plasticity of clay soils. As no comprehensive study has been conducted in this regard specifically on Tehran clay soil yet, this research studies experimentally the effect of adding different percentages of tire powder to clay soil at the Atterberg limits of clay soils with two different types of plasticity. More over according to previous studies, the effect of tire powder on other geotechnical properties of clay soils and the advantages and disadvantages of using tire powder in clay soils are discussed. The results indicate that addition of tire powder to clay soils has positive effects on reducing the Atterberg limits, increasing efficiency, and improving resistance, permeability, swelling reduction, and settlement properties, and reducing soil density and it can be used as an additive in improving clay soils.

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