Development of an In-Situ Method for Continuous Evaluation of the Resilient Modulus of Pavement Subgrade

Development of an In-Situ Method for Continuous Evaluation of the Resilient Modulus of Pavement Subgrade PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 109

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Book Description
Pavement designs, materials and uses vary around the world, but engineers typically employ the resilient moduli of pavement materials as the primary means of evaluating those materials. Unfortunately, the majority of tests used to determine the resilient modulus of materials are performed in the laboratory where the material either has been removed from the in-situ conditions or has been reconstituted. Soil samples which are removed from the ground using various techniques are at best moderately disturbed. Typically the testing of these samples is performed in a triaxial device equipped for repetitive axial loading. The strain used to calculate the resilient modulus is the recoverable portion of the deformation response. The fact that this response varies with state of stress is widely accepted, but the laboratory test results continue to be used for lack of a more useful and convenient method of determining resilient moduli (Yoder and Witczak, 1975). The purpose of this study is to develop a method for continuous, in-situ evaluation of the resilient modulus of subgrade material under a highway pavement using seismic waves. Although this technique is not mobile and the equipment is fully embedded in the soil under the pavement, it provides a more accurate means of evaluating resilient modulus. This approach can then be used as a benchmark with which to compare the laboratory results to improve design methods as well as our fundamental understanding of the behavior of pavement materials in the field.

Development of an In-Situ Method for Continuous Evaluation of the Resilient Modulus of Pavement Subgrade

Development of an In-Situ Method for Continuous Evaluation of the Resilient Modulus of Pavement Subgrade PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 109

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Book Description
Pavement designs, materials and uses vary around the world, but engineers typically employ the resilient moduli of pavement materials as the primary means of evaluating those materials. Unfortunately, the majority of tests used to determine the resilient modulus of materials are performed in the laboratory where the material either has been removed from the in-situ conditions or has been reconstituted. Soil samples which are removed from the ground using various techniques are at best moderately disturbed. Typically the testing of these samples is performed in a triaxial device equipped for repetitive axial loading. The strain used to calculate the resilient modulus is the recoverable portion of the deformation response. The fact that this response varies with state of stress is widely accepted, but the laboratory test results continue to be used for lack of a more useful and convenient method of determining resilient moduli (Yoder and Witczak, 1975). The purpose of this study is to develop a method for continuous, in-situ evaluation of the resilient modulus of subgrade material under a highway pavement using seismic waves. Although this technique is not mobile and the equipment is fully embedded in the soil under the pavement, it provides a more accurate means of evaluating resilient modulus. This approach can then be used as a benchmark with which to compare the laboratory results to improve design methods as well as our fundamental understanding of the behavior of pavement materials in the field.

Masters Theses in the Pure and Applied Sciences

Masters Theses in the Pure and Applied Sciences PDF Author: Wade H. Shafer
Publisher: Springer Science & Business Media
ISBN: 1461524539
Category : Science
Languages : en
Pages : 391

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Book Description
Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS)* at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dis semination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the though that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all concerned if the printing and distribution of the volumes were handled by an international publishing house to assure improved service and broader dissemi nation. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Corporation of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 37 (thesis year 1992) a total of 12,549 thesis titles from 25 Canadian and 153 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this impor tant annual reference work. While Volume 37 reports theses submitted in 1992, on occasion, certain uni versities do report theses submitted in previous years but not reported at the time.

Dynamic Geotechnical Testing II

Dynamic Geotechnical Testing II PDF Author: Ronald J. Ebelhar
Publisher: ASTM International
ISBN: 0803118775
Category : Dinamik test etme- Kongreler
Languages : en
Pages : 433

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Book Description


Measuring in Situ Mechanical Properties of Pavement Subgrade Soils

Measuring in Situ Mechanical Properties of Pavement Subgrade Soils PDF Author: David E. Newcomb
Publisher: Transportation Research Board
ISBN: 9780309068574
Category : Science
Languages : en
Pages : 84

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Book Description
This synthesis report will be of interest to pavement and geotechnical design and research engineers, geologists and engineering geologists, and related laboratory personnel. It describes the current practice for measuring in situ mechanical properties of pavement subgrade soils. The tests conducted to measure the mechanical properties of soil strength and stiffness are the primary topics, and these are discussed in the context of design procedures, factors affecting mechanical properties, and the variability of measurements. Information for the synthesis was collected by surveying U.S., Canadian, and selected European transportation agencies and by conducting a literature search. This TRB report provides information on existing and emerging technologies for static and dynamic, and destructive and nondestructive testing for measuring in situ mechanical properties of pavement subgrade soils. Correlations between in situ and laboratory tests are presented. The effects of existing layers on the measurement of subgrade properties, and soil spatial and seasonal variability are discussed. Most importantly, the use of soil properties in pavement design and evaluation are explained. New applications or improvements to existing test methods to support the use of mechanistic/stochastic-based pavement design procedures are also explained.

Comparative Evaluation of Subgrade Resilient Modulus from Non-destructive, In-situ, and Laboratory Methods

Comparative Evaluation of Subgrade Resilient Modulus from Non-destructive, In-situ, and Laboratory Methods PDF Author:
Publisher:
ISBN:
Category : Pavements
Languages : en
Pages : 96

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Book Description
Field and laboratory testing programs were conducted to develop models that predict the resilient modulus of subgrade soils from the test results of DCP, CIMCPT, FWD, Dynaflect, and soil properties. The field testing program included DCP, CIMCPT, FWD, and Dynaflect testing, whereas the laboratory program included repeated load triaxial resilient modulus tests and physical properties and compaction tests. Nine overlay rehabilitation pavement projects in Louisiana were selected. A total of four soil types (A-4, A-6, A-7-5, and A-7-6) were considered at different moisture-dry unit weight levels. The results of the laboratory and field testing programs were analyzed and critically evaluated. A comprehensive statistical analysis was conducted on the collected data. The results showed a good agreement between the predicted and measured resilient modulus from the various field test methods considered. The DCP and CIMCPT models were enhanced when the soil moisture content and dry unit weight were incorporated. The results also showed that, among all back calculated FWD moduli, those back calculated using ELMOD 5.1.69 software had the best correlation with the measured Mr. Finally, the Mr values estimated using the approach currently adopted by the LADOTD were found to correlate poorly with the measured Mr values.

Evaluation of In-Situ Stiffness of Subgrade by Resilient and FWD Modulus

Evaluation of In-Situ Stiffness of Subgrade by Resilient and FWD Modulus PDF Author: Daehyeon Kim
Publisher:
ISBN: 9781622600380
Category :
Languages : en
Pages :

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Book Description


Center for Transportation Research, Bureau of Engineering Research, the University of Texas at Austin

Center for Transportation Research, Bureau of Engineering Research, the University of Texas at Austin PDF Author: University of Texas at Austin. Center for Transportation Research
Publisher:
ISBN:
Category :
Languages : en
Pages : 30

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Book Description


Evaluation of Procedure to Estimate Subgrade Resilient Modulus for Use in Pavement Structural Design

Evaluation of Procedure to Estimate Subgrade Resilient Modulus for Use in Pavement Structural Design PDF Author: Harold L. Von Quintus
Publisher:
ISBN:
Category : Pavements, Asphalt
Languages : en
Pages : 54

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Book Description
The Kansas Department of Transportation (DOT) uses the 1993 DARWin version of the 1986 AASHTO Guide to design rigid and flexible pavements. One of the inputs needed for the flexible pavement design procedure is the modulus of the subgrade soils, which has an effect on the total pavement thickness. Different procedures can be used to estimate the effective roadbed resilient modulus for flexible pavement design and effective modulus of subgrade reaction for rigid pavement design. As part of the study entitled Determination of the Appropriate Use of Pavement Surface History in the KDOT Life-Cycle Cost Analysis Process, an evaluation of the procedure that Kansas DOT uses to estimate the effective subgrade resilient modulus was completed. This report provides the results of that evaluation.

Resilient Modulus Testing for Pavement Components

Resilient Modulus Testing for Pavement Components PDF Author: Mary Stroup-Gardiner
Publisher: ASTM International
ISBN: 0803134614
Category : Pavements
Languages : en
Pages : 274

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Book Description
"Resilient modulus indicates the stiffness of a soil under controlled confinement conditions and repeated loading. The test is intended to simulate the stress conditions that occur in the base and subgrade of a pavement system. Resilient modulus has been adopted by the U.S. federal highway administration as the primary performance parameter for pavement design. We thank those who prepared these papers, the reviewers who provided anonymous peer reviews, and those who participated in the symposium. We hope this STP encourages more work to improve the testing standard and the value of the Resilient Modulus test."

Estimating Stiffness of Subgrade and Unbound Materials for Pavement Design

Estimating Stiffness of Subgrade and Unbound Materials for Pavement Design PDF Author: Anand J. Puppala
Publisher: Transportation Research Board
ISBN: 0309098114
Category : Technology & Engineering
Languages : en
Pages : 139

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Book Description
At head of title: National Cooperative Highway Research Program.