Experimental Verification of Resilient Deformation for Granular Subgrades

1998 ◽  
Vol 1639 (1) ◽  
pp. 12-22 ◽  
Author(s):  
W. Virgil Ping ◽  
Zenghai Yang
Keyword(s):  
Moisture Content ◽  
Laboratory Test ◽  
Resilient Modulus ◽  
Soil Samples ◽  
Load Test ◽  
Experimental Program ◽  
Rigid Plate ◽  
Plate Load Test ◽  
Reconstituted Soil ◽  
Moisture Conditions

Results of an experimental program utilizing the repetitive rigid plate load test in a test-pit facility and the laboratory resilient modulus test are presented for five typical subgrades in Florida. The subgrade materials were tested in the test pit under three different moisture conditions, that is, (1) optimum, (2) drained and dried, and (3) soaked. Laboratory resilient modulus tests were conducted on reconstituted soil samples simulating the various moisture conditions. The resilient modulus was significantly affected by the moisture content of granular subgrades. A comparison between the deformations measured from the test-pit test and the deformation calculated from the laboratory test was made. It was experimentally verified that the resilient modulus resulting from the laboratory triaxial test could be used to predict the resilient deformation of pavement subgrade layers.

Field Verification of Laboratory Resilient Modulus Measurements on Subgrade Soils

1997 ◽  
Vol 1577 (1) ◽  
pp. 53-61 ◽  
Author(s):  
W. Virgil Ping ◽  
Ling Ge
Keyword(s):  
Resilient Modulus ◽  
Input Parameter ◽  
Field Performance ◽  
Load Test ◽  
Engineering Properties ◽  
Experimental Program ◽  
Plate Load Test ◽  
Analysis And Design ◽  
Field Plate ◽  
Simplified Procedure

The resilient modulus of roadbed soils is a required input parameter in pavement analysis and design. Most recent research has concentrated on the laboratory resilient modulus test and its correlations with other engineering properties determined from laboratory tests. However, little effort has been focused on calibrating the laboratory resilient modulus measurements using field performance data. The results are presented of an experimental program to evaluate the field bearing characteristics of in-service pavement subgrade layers and to conduct the laboratory resilient modulus measurements on the reconstituted soil samples simulating the field moisture and density conditions. A simplified procedure was adopted for comparing the laboratory equivalent resilient modulus values with the modulus of elasticity of the subgrade layer obtained from the field plate load test. The laboratory resilient modulus test results compared reasonably well with the field plate layer moduli.

Seasonal Variation of Backcalculated Subgrade Moduli

1997 ◽  
Vol 1577 (1) ◽  
pp. 70-80 ◽  
Author(s):  
Bing Long ◽  
Mustaque Hossain ◽  
Andrew J. Gisi
Keyword(s):  
Seasonal Variation ◽  
Moisture Content ◽  
Temperature Effect ◽  
Resilient Modulus ◽  
Natural Soil ◽  
Temperature Regimes ◽  
Almost All ◽  
Moisture Conditions ◽  
Falling Weight ◽  
And Behavior

Seasonal variations in pavement material properties and behavior due to variations in temperature and moisture conditions are known to affect the structural performance of pavement. Temperature, subgrade moisture content, and falling weight deflectometer (FWD) deflection data were collected monthly on four asphalt pavement test sections for a year. Subgrade moduli were backcalculated using the elastic layer theory with two calculation schemes and pavement models. Backcalculation of subgrade moduli by subdividing the subgrade into a compacted subgrade layer and a natural soil subgrade layer resulted in compacted subgrade moduli that are more sensitive to the seasonal variation for all sites. It was found that for almost all sites, the patterns of subgrade response, in terms of subgrade moduli versus subgrade moisture content, simulated sine-shaped forms signifying a temperature effect. The temperature effect was confirmed by the strong correlation between backcalculated subgrade moduli and pavement surface temperature during FWD tests. The lowest backcalculated subgrade moduli were obtained for two sections during months when asphalt surface temperatures were excessively high (greater than 40°C). Both backcalculation schemes showed similar trends in variation of subgrade moduli over seasons. When the AASHTO relative damage concept was used to compute the effective roadbed soil resilient modulus for design, similar values were found for both schemes for most of the sites. The minimum frequency of FWD testing to capture the seasonal variation of subgrade was found to be three tests per year, or testing every fourth month, assuming that unusually high temperature regimes could be avoided.

Experimental Study on Size Effect of Plate Load Test in Roadbed Compaction Quality Detection

2011 ◽  
Vol 230-232 ◽  
pp. 367-371
Author(s):  
Xiao Yong Li ◽  
Kang Xu ◽  
Si Yuan Wang
Keyword(s):  
Experimental Study ◽  
Laboratory Test ◽  
Size Effect ◽  
Test Section ◽  
Regression Equation ◽  
Load Test ◽  
Test Results ◽  
Plate Load Test ◽  
Quality Detection ◽  
The One

There are three normal sizes of loading plate as 30 cm, 50 cm, 75 cm in roadbed compaction quality detection. The size effect rule for coefficient of foundation is obtained from the investigation on plate load test results by the experiment in lab. The laboratory test may control well the conditions by building the test section modeling the roadbed. The test section is 15 m by 5m. The diameters of loading plate used is 30cm, 35cm, 40cm, 45cm, 50cm, 55cm, 60cm, 65cm, 70cm and 75cm in the test. The regression equation between coefficients of foundation measured by different size of loading plate has been concluded. It is obtained that the ratio of coefficients of foundation between the plate of 50 cm and 30cm is 1.6 for granule filler, 1.65 for grind filler, and the one between the plate of 70 cm and 30cm is 2.17 for granule filler, 2.3 for grind filler.

Modeling Stress- and Moisture-Induced Variations in Pavement Layer Moduli

2003 ◽  
Vol 1860 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Cheryl Richter ◽  
Charles W. Schwartz
Keyword(s):  
Moisture Content ◽  
Constitutive Model ◽  
Resilient Modulus ◽  
Monitoring Program ◽  
Elastic Theory ◽  
Pavement Materials ◽  
Seasonal Basis ◽  
Stress States ◽  
Stress Dependent ◽  
Moisture Conditions

The in situ moduli of unbound pavement materials vary on a seasonal basis as a function of temperature and moisture conditions. The development of empirical models to predict backcalculated pavement layer moduli as a function of moisture content and stress state is addressed. The work is based on data collected via the Seasonal Monitoring Program of the Long-Term Pavement Performance Program. This research identified fundamental incompatibilities between the stress states computed from layer moduli backcalculated using linear layered-elastic theory and those used in laboratory resilient modulus testing. Important implications of this finding are that (a) application of laboratory-derived constitutive model coefficients in combination with stress states computed using linear layered-elastic theory may yield inaccurate stress-dependent modulus values and (b) meaningful advances in the state of the art for backcalculation of pavement layer moduli cannot be achieved without addressing the inaccuracies and limitations inherent in the use of linear layered-elastic theory to model nonlinear pavement response. Other important findings include the following: (c) variation in moisture content is not always the most important factor causing seasonal variations in pavement layer moduli and (d) a constitutive model form suitable for approximately incorporating the stress and moisture sensitivity of layer moduli backcalculated using linear layered-elastic procedures for practical design purposes is identified.

scholarly journals Characterization and Classification of Geotechnical Index Properties of Shallow Soil Deposits at Oworoshoki Area, Kosofe Local Government, Lagos, Nigeria

2021 ◽  
Vol 04 (01) ◽  
Author(s):  
I.T. Peni ◽  
Keyword(s):  
Particle Size ◽  
Specific Gravity ◽  
Moisture Content ◽  
Particle Size Distribution ◽  
Laboratory Test ◽  
Soil Samples ◽  
Unit Weight ◽  
Index Properties ◽  
Plastic Limit ◽  
Natural Moisture Content

The study of geotechnical index properties of soils in Oworoshoki, Kosofe, Lagos State was conducted to characterize and classify the index properties of soil samples. Disturbed and undisturbed soils were collected at different shallow depths (1m, 2m and 3m) from the study area and laboratory test was conducted. The laboratory test conducted includes natural moisture content, atterberg limits (liquid limit and plastic limit), particle size distribution, specific gravity, unit weight and hydrometer. The results of the test were gotten: natural moisture content as 23.5%, 24.5% and 25.3% , liquid limits (LL) 28.68%, 26.64% and 29.10%, Oworoshoki is non-plastic for the three depths i.e. plastic limit (PL) is 0, particle size distribution percentage passing through BS #200 (0.075mm) are 95.97 %, 97.97%, 98.10% and this shows that the soil sample contain much silt, the samples are non-plastic for all depths (1m, 2m and 3m), specific gravity as 2.61, 2.55 and 2.60, unit weight as 17.5 KN/m3, 18.1kn/m3 and 18.9KN/m3 and hydrometer percentage passing through BS #200 (0.075mm) as 95.97% at 1.0m depth, 97.97% at 2.0m depth and 98.10% at 3.0m depth. Hydrometer test was conducted because 95.97% passes sieve 0.075mm.This shows that the soil contain high amount of silt. Soils from depth 1.0m, 2.0m and 3.0m are non-plastic (NP) because the Plastic Index (PI=0) and the soil samples are classified as A – 3 according to American Association of State Highway and Transportation Officials (AASHTO) System.

scholarly journals Evaluation of Reclaimed Hydrated Fly Ash as an Aggregate for Sustainable Roadway Base Material

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Mark H. Wayne ◽  
David J. White ◽  
Jayhyun Kwon ◽  
Jacek Kawalec
Keyword(s):  
Fly Ash ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Base Material ◽  
Performance Testing ◽  
Load Test ◽  
Plate Load Test ◽  
Laboratory Test Results ◽  
Class C

This paper summarizes the findings from laboratory and field performance testing of reclaimed hydrated class C fly ash (HFA) stabilized with a triangular aperture geogrid. This phase of testing was performed on HFA laboratory specimens and field test sections. The laboratory test results provided estimates for design input values, while the field testing assessed performance characteristics including the as-constructed modulus of the subgrade reaction, the in situ resilient modulus, and permanent deformation. For the laboratory portion, all results were derived from tests conducted on specimens immediately after sample preparation and after a 7-day cure. The compressive strength of reclaimed hydrated class C fly ash increases with curing. The strength of the HFA material can be further increased when mixed with a chemical stabilizer. For this project, chemical stabilization with lime was not viable because the lime supplier was too far from both HFA source and project site. Based on cyclic plate load tests, the in situ resilient modulus of the HFA and geogrid-stabilized HFA layers were determined on site. This paper reports the findings from the laboratory and field plate load test and highlights the potential use of geogrids in the stabilization of HFA.

scholarly journals Factorial design study of total petroleum contaminated soil treatment using land farming technique

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Ehizonomhen S. Okonofua ◽  
Kayode H. Lasisi ◽  
Eguakhide Atikpo
Keyword(s):  
Moisture Content ◽  
Factorial Design ◽  
Contaminated Soil ◽  
Soil Samples ◽  
Optimization Techniques ◽  
Cow Dung ◽  
Optimum Point ◽  
Input Parameters ◽  
Substrate Moisture ◽  
Land Farming

AbstractLand farming technique was used to treat hydrocarbon contaminated soil collected from a crude oil spill sites in Edo State, Nigeria. Calibrated standard auger was used to collect soil samples from the site at depth below 30 cm. The samples were characterized and classified. Cow dung and NPK fertilizer were added as additives to complement the nutriments of the soil samples before total petroleum hydrocarbon (TPH) quantification and remediation procedures. Factorial design was applied to vary the input parameters such as pH, mass of substrate, moisture content and turning times of land farming so to ascertain the optimal conditions for the procedure. The result revealed that the in-situ TPH value was 5000 mg kg− 1 on the average and after 90 d of treatment, TPH reduced to 646 mg kg− 1. The turning rate, pH, moisture content and mass of substrate hade 83, 4.36, 0.48 and 0.046% contribution, respectively, for the degradation process using land farming treatment. Numerical optimization techniques applied in the optimum point for land farming input parameters to achieve predicted maximum removal of 99% were evaluated as pH, mass of substrate, moisture content and turning rate to be 6.01, 1 kg, 10% and 5 times in a week, respectively. TPH removed at this optimum point was 98% reducing from 5000 to 636 mg kg− 1. The high coefficient of determination (r2 = 0.9865) as observed in the closeness of predicted and experimental values reflects the reliability of the model and hence, land farming practice with close attention on turning rate as revealed by this study, is recommended for TPH contaminated soil remediation.

scholarly journals Prediction of Effects of Geogrid Reinforced Granular Fill on the Behaviour of Static Liquefaction

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
A. Hemalatha ◽  
N. Mahendran ◽  
G. Ganesh Prabhu
Keyword(s):  
Bearing Capacity ◽  
Load Test ◽  
Test Results ◽  
Plate Load Test ◽  
Large Size ◽  
Static Liquefaction ◽  
Granular Fill ◽  
Size Dimension ◽  
Subgrade Modulus ◽  
Different Thickness

The experimental investigation on the effects of granular fill and geogrid reinforced granular fill on the behaviour of the static liquefaction potential of the subsoil is reported in this study. A series of plate load test were carried out with different thickness of the granular fill, number of geogrid layers, and size/dimension of the footing. The test results were presented in terms of bearing capacity and subgrade modulus for the settlement ofδ10,δ15, andδ20. The experimental results revealed that the introduction of granular fill significantly increases the bearing capacity and effectively control the settlement behaviour of the footing. The introduction of geogrid in granular fill enhanced the Percentage of Control in Settlement and Bearing Capacity Ratio by a maximum of 328.54% and 203.41%, respectively. The introduction of geogrid in granular fill interrupts the failure zone of the granular fill and enhances the subgrade modulus of the footing by a maximum of 255.55%; in addition subgrade modulus of the footing was increased with an increase in the number of geogrid layers. Based on the test results it is suggested that the footing with large size has beneficial improvement on the reinforced granular fill.

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