scholarly journals Reliability Evaluation of Compaction Water Content of Plantain Peel Ash Treated Lateritic Soil

2021 ◽  
Vol 18 (1) ◽  
pp. 47-54
Author(s):  
K. Ishola ◽  
O.A. Olawuyi ◽  
P. Yohanna ◽  
A.A. Bello ◽  
R.O. Sani ◽  
...  
Keyword(s):  
Water Content ◽  
Coefficient Of Variation ◽  
Lateritic Soil ◽  
Safety Index ◽  
Soil Factors ◽  
British Standard ◽  
Road Pavement ◽  
Reliability Method ◽  
Determining Factors ◽  
Index Value

A first-order reliability method (FORM)was employed to assess the compaction water content, CWC (i.e optimum moisture content) of residual lateritic soil mixed with plantain peel ash (PPA) and compacted with British Standard Light (BSL)and British Standard Heavy (BSH)energies, for flexible pavement applications. A Multi-linear regression model was generated from values obtained via laboratory tests using Mini-tab R15 software, which served as a performance function that was applied for the analysis. Using the regression models for CWC, established distributions for the relevant soil factors, safety index (SI) was computed using CWC as a dependent factor and the soil factors Plantain Peel Ash (PPA); Plasticity Index (PI); Percentage File (PF); Specific Gravity (Gs) and Compactive Effort (CE)as self-determining factors). The results revealed that the safety index is sensitive to changeability in the soil factors. Outcome from the analysis show that Gs and CE are greatly affected by alteration in the coefficient of variation (COV), and so it is essential to control Gs and CE in lateritic soil–PPA mixes in road pavements. From the safety index values it reveals that PPA content has a minimal consequence as its value virtually remained constant at all COV used. Stochastically, lateritic soil mixed with PPA produces an acceptable safety index value of 1.0, as mentioned by the Nordic Committee on Building Regulation (NCBR) at 10% COV for BSH of compaction water content only. Therefore a more effective additive such as cement, lime, or bitumen is recommended for modeling CWC of lateritic soil-PPA mixes for road pavement at 10–100% series of COV. Keywords: Coefficient of variation; compaction water content; lateritic soil; plantain peel ash; reliability index

The Ontario bridge code—Development and implementation

1984 ◽  
Vol 11 (4) ◽  
pp. 824-832
Author(s):  
R. A. Dorton
Keyword(s):  
Highway Bridges ◽  
Safety Index ◽  
Design Code ◽  
Limit States ◽  
Safety Level ◽  
New Development ◽  
Live Loads ◽  
Index Value ◽  
Correct Understanding ◽  
Short Time

The Ontario Highway Bridge Design Code was first issued in 1979 and has since been used for the design and evaluation of most bridges in Ontario. The code is in metric SI units, written in a limit states format, and calibrated to a target safety index value of 3.5. It has produced bridges with a more consistent safety level and capable of carrying design live loads twice those previously prescribed. Feedback from users was obtained and their concerns considered in formulating the provisions of the seeond edition in 1983. New bridge codes can be written in a short time and implemented most readily within a relatively small jurisdiction having control of all highways, bridges, and vehicles. Communications between the writers and potential users are important throughout the preparation and implementation phases. It is essential that a commentary volume be issued with a code to ensure correct understanding and interpretation of new provisions. Computer programs should be available, incorporating the code technology before the use of a new code becomes mandatory. Future code needs and likely areas of new development are outlined in the paper. Key words: calibration, codes, computer systems, highway bridges, loadings, safety, structures.

scholarly journals Performance Evaluation of the Effect of Sodium Hydroxide on Geotechnical Properties of Lateritic Soil for Rural Road Construction

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Ibrahim I Abdulkarim ◽  
Sa’eed Y Umar
Keyword(s):  
Sodium Hydroxide ◽  
Construction Material ◽  
Energy Levels ◽  
Molar Concentration ◽  
Engineering Properties ◽  
Lateritic Soil ◽  
Rural Roads ◽  
British Standard ◽  
Minimum Requirement ◽  
General Specification

This study explored the potentials of sodium hydroxide (NaOH) for the improvement of the properties of lateritic soil (LS) intended for use as construction material for rural roads in the North-eastern part of Nigeria. The soil was classified as A-6(13) and CL according to the American Association of State Highway and Transport Officials (AASHTO M 145-2012) and the Unified Soil Classification System (ASTM D 2487-2011). The soil is treated to evaluate the effectiveness of NaOH in treating lateritic soil with 1, 3 and 7 molar concentration of NaOH and compacted using two methods of compaction, the British Standard Light (BSL) and British Standard Heavy (BSH). Unconfined compressive strength (UCS) and Californian bearing ratio (CBR) tests were conducted on the compacted specimens. The results obtained show a general improvement in the engineering properties of the soil with increase in molar concentration of NaOH, particularly, when compacted at the BSH energy level. The maximum 7 days UCS values of 909 kN/m2 and 1106 kN/m2 were obtained at 7 molar concentration for the BSL and BSH energy levels. These values are within the range of 750 – 1500 kN/m2 UCS value specified by the Nigerian General Specification (2013) for sub-base materials. In the case of the CBR, at 3 and 7 molar concentrations for BSH effort, CBR values of 33% and 38% were recorded while 34% CBR value was recorded at 7 molar concentration for BSL effort, these values also met the minimum requirement of 30% CBR specified by the Nigerian General Specification for sub-base construction.Keywords— Lateritic, Sodium hydroxide, Soil, Rural roads. 

scholarly journals Safety parameters calibration in the structural design of sewer liners

2018 ◽  
Vol 45 ◽  
pp. 00096
Author(s):  
Arkadiusz Szot
Keyword(s):  
Analytical Solutions ◽  
Structural Design ◽  
Safety Index ◽  
Safety Factors ◽  
Load Bearing Capacity ◽  
First Order Reliability Method ◽  
First Order ◽  
Reliability Method ◽  
Safety Parameters ◽  
Global Safety Factor

The article concerns aspects of safety in the process of designing continuous polymer liners used to strengthen and seal sewers and drains. The issues of safety coefficients, the variability of basic loadbearing parameters of liners and the problem of sensitivity of analytical solutions describing load-bearing capacity are discussed. The currently used magnitude of safety factors has been verified. The results of an examination on the safety index of liners for strengthening sewers has been presented in the paper. The necessity for the verification of current concepts of liner safety normalisation was herein addressed. A postulation to abandon the analogy of liners for newly constructed pipes was formulated. Calculations using the Hasofer-Lind safety index (First Order Reliability Method) were performed in some cases. A verification and evaluation of the global safety factor for sewer liners were herein carried out.

Analysis of Fat-Soluble Vitamins. XVII. Comparison of Chemical and Biological Assays of Vitamin D

1978 ◽  
Vol 61 (1) ◽  
pp. 117-121
Author(s):  
Frits J Mulder ◽  
Roel Strik
Keyword(s):  
Vitamin D ◽  
Coefficient Of Variation ◽  
Chemical Method ◽  
Geometric Mean ◽  
British Standard Institution ◽  
Geometric Mean Ratio ◽  
British Standard ◽  
Biological Assays ◽  
Chemical Assay ◽  
Fat Soluble Vitamins

Abstract Two methods, the chemical assay using maleic anhydride addition and the British Standard Institution chick bioassay, were used to analyze samples from vitamin D3 resin batches manufactured over a period of about 4 years. Statistical analysis of data obtained for vitamin D shows that (1) the reproducibility of the chemical assay has a coefficient of variation of 0.7% ; (2) the chemical assay is suitable for controlling the dilution procedure of resins in oil, the product variability being represented by a coefficient of variation of 1.7% ; (3) the agreement between the average values obtained by the bioassay and the chemical method is satisfactory (geometric mean ratio = 99.7%, n = 39); (4) the chick bioassay has 95% limits of variation of about ±30% for single results.

Lateritic Soil Treated with Waste Wood Ash As Liner in Landfill Construction

2019 ◽  
Vol 25 (2) ◽  
pp. 127-139 ◽  
Author(s):  
Johnson R. Oluremi ◽  
Adrian O. Eberemu ◽  
Stephen T. Ijimdiya ◽  
Kolawole J. Osinubi
Keyword(s):  
Compressive Strength ◽  
Hydraulic Conductivity ◽  
Unconfined Compressive Strength ◽  
Wood Ash ◽  
Engineering Properties ◽  
Volumetric Shrinkage ◽  
Lateritic Soil ◽  
Waste Wood ◽  
K Value ◽  
British Standard

ABSTRACTInherent variability in engineering properties of lateritic soil in relation to its plasticity, permeability, strength, workability, and natural moisture content, has made it an unpredictable material for use in civil engineering works, resulting in the need for its treatment by stabilization. A lateritic soil classified as A-6(6) and CL, according to American Association of State Highway and Transportation Officials and Unified Soil Classification System of ASTM (2011), was treated with up to 10 percent waste wood ash (WWA). Compaction was carried out using four energies, namely, reduced British Standard light, British Standard light (BSL), West African Standard, and British Standard heavy, on samples, which were then examined for hydraulic conductivity, volumetric shrinkage, and unconfined compressive strength as major criteria for use as liner and for the development of acceptable zones. Specimens with 4 percent WWA content compacted with a minimum BSL energy satisfied the maximum hydraulic conductivity (k) value of 1 × 10−9 m/s, maximum volumetric shrinkage strain of 4 percent, and minimum unconfined compressive strength value of 200 kN/m2 required for use as liner in engineered landfills. The overall acceptable zone was enlarged for up to 4 percent WWA content, thereby accommodating higher moulding water content, but the minimum compactive effort required to achieve it became reduced. The beneficial treatment of lateritic soil with up to 4 percent WWA will perform satisfactorily as liner and covers in waste containment application and will minimize the pollution and environmental impact of wood waste disposal.

scholarly journals Global Safety Factor or Nonlinear Design of Concrete Structures

2011 ◽  
Vol 57 (3) ◽  
pp. 331-339 ◽  
Author(s):  
Sz. Wolinski
Keyword(s):  
Nonlinear Analysis ◽  
Coefficient Of Variation ◽  
Concrete Structures ◽  
Resistance Coefficient ◽  
Sensitivity Factor ◽  
Mean Values ◽  
Nonlinear Design ◽  
Global Safety Factor ◽  
Index Value ◽  
Partial Factor

Abstract The paper focuses on different approaches to the safety assessment of concrete structures designed using nonlinear analysis. The method based on the concept of partial factors recommended by Eurocodes, and methods proposed by M. Holicky, and by the author of this paper are presented, discussed and illustrated on a numerical example. Global safety analysis by M. Holicky needs estimation of the resistance coefficient of variation from the mean and characteristic values of resistance, and requires two separate nonlinear analyses. The reliability index value and the sensitivity factor for resistance should be also identified. In the method proposed in this paper, the resistance coefficient of variation necessary to calculate the characteristic value of resistance may be adopted from test results and the resultant partial factor for materials properties, and may be calculated according to Eurocodes. Thus, only one nonlinear analysis from mean values of reinforcing steel and concrete is required

Stabilization Potential of Cement Kiln Dust Treated Lateritic Soil

2016 ◽  
Vol 23 ◽  
pp. 52-63 ◽  
Author(s):  
Johnson R. Oluremi ◽  
Rafat Siddique ◽  
Ekundayo P. Adeboje
Keyword(s):  
Moisture Content ◽  
Water Content ◽  
West African ◽  
Lateritic Soil ◽  
Cement Kiln Dust ◽  
Cement Kiln ◽  
Construction Company ◽  
Ogun State ◽  
Compactive Effort ◽  
Kiln Dust

A dark reddish-brown lateritic soil collected from existing borrow pit abandoned by Reynold Construction Company Ltd behind New WAZOBIA Market on Latitude 08008′N and Longitude 04014′E along Ogbomoso-Ilorin Express road, Ogbomoso, Oyo State. Nigeria was treated with cement kiln dust (CKD), a by-product of long wet kiln, obtained from West African Portland Cement Organisation (WAPCO), Ewekoro, Ogun State, Nigeria, under varying moulding water content.The results show gradual reduction in the plasticity index of the samples, decrease in the maximum dry densities (MDD) with corresponding increase in the optimum moisture contents (OMC) of the treated soil samples. The unconfined compressive strength (UCS) of the treated samples increases with both increase in the treatment content as well as compactive effort from British Standard (BS) to West African Standard (WAS) however, there was reduction in the UCS with varying moulding water content as the water content increases and decreases relative to optimum moisture content. The maximum UCS was obtained at optimum moisture content.Cement kiln dust though regarded as waste can therefore serve as potential material in the stabilization of the lateritic soil when compacted at moisture content within its OMC.

A comparison of the topmaking performance of wool from sheep selected by index and visual methods

1999 ◽  
Vol 39 (8) ◽  
pp. 941 ◽  
Author(s):  
A. L. Vizard ◽  
K. A. Hansford
Keyword(s):  
Body Weight ◽  
Coefficient Of Variation ◽  
Selection Index ◽  
Fibre Diameter ◽  
Visual Assessment ◽  
Index Selection ◽  
Visual Methods ◽  
Merino Sheep ◽  
Fleece Weight ◽  
Index Value

Summary. The topmaking performance of fleeces from sheep that were ranked high or low on index selection using objective measurement was compared with that of sheep from the same flock that were ranked high or low on visual assessment. A flock of 451 15-month-old fine-wool Merino sheep were classed by 2 experienced fine-wool sheep classers into 3 grades: best, average and culls. Forty-four sheep were assessed as ‘best’ and 77 sheep were graded as ‘culls’ by both classers. These sheep were defined as the ‘best visual’ and ‘worst visual’ sheep, respectively. Measurements of clean fleece weight, mean fibre diameter, coefficient of variation of fibre diameter and body weight were used in a selection index to rank all sheep in the flock. The selection index was designed to rapidly reduce mean fibre diameter and slowly increase clean fleece weight, whilst maintaining staple strength and body weight. The 44 sheep with the highest index value were defined as ‘best index’ sheep and the group of 77 sheep with the lowest index or obvious physical faults were defined as the ‘worst index’ sheep. Twenty-five fleeces were randomly selected from each of the ‘best’ and ‘worst visual’, ‘best’ and ‘worst index’ sheep for individual processing through to top. The fleeces from the ‘best index’ sheep produced greater quantities of tops that were significantly finer, longer, of lower curvature and produced less noil than all other groups. In contrast to the large difference in quality between tops from the ‘best’ and ‘worst index’ sheep, there was little difference in quality between tops from the ‘best’ and ‘worst visual’ sheep. This indicates that the traditional wool producer views of wool quality are unrelated to processing performance. It was concluded that Merino sheep selected by index selection using direct measurement of fleece weight, mean fibre diameter and coefficient of variation of diameter as selection criteria produced greater quantities of wool of superior processing performance to that from sheep selected using visual assessment.

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