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Title:

New Approaches for Modeling Subgrade Nonlinearity in Flexible Pavements
Cover of New Approaches for Modeling Subgrade Nonlinearity in Flexible Pavements

Accession Number:

01550539

Record Type:

Component

Availability:

Transportation Research Board Business Office

500 Fifth Street, NW
Washington, DC 20001 United States

Abstract:

The primary objective of this paper is to present new methods in characterizing flexible pavements that possess nonlinear subgrade behavior using deflection data from falling weight deflectometer (FWD). The two techniques to be introduced are Simplified Deflection Modeling and Deflection Ratio (DefR) approach. FWD deflection data can be modelled accurately using an exponential curve in a mathematical form of Y = K sub 1 exp (-r/K sub 2). K sub 1 is equal to deflection at D sub 0 in micron and K sub 2 is the structural parameter at the respective sensor location. The exponential curve was found to have the desired characteristics that match the FWD deflection bowls and is termed as a simplified deflection model (SDM). K sub 2 parameter is found to have a direct relationship with the material constant, value of the subgrade and it is taken as a measurement of the nonlinearity of the pavement layer. When the K sub 2 parameter falls within the range from 100 to 300, it is associated with high degree of subgrade nonlinearity. As K sub 2 increases and approaches 500, the pavement structure is observed to possess linear elastic behaviour. In the second method, the DefR is defined as the ratio of the FWD deflection of a sensor divided by the deflection of the preceding sensor. For pavements that exhibit nonlinear subgrade behavior, the DefR shows an increasing trend for FWD sensors located at 300 mm and beyond. The two techniques have shown to be simple and robust, and suitable for use in modeling subgrade nonlinearity.

Supplemental Notes:

This paper was sponsored by TRB committee AFD80 Strength and Deformation Characteristics of Pavement Sections. Alternate title: New Approaches for Modeling Subgrade Nonlinearity in Thin Surfaced Flexible Pavements.

Monograph Accession #:

01550057

Report/Paper Numbers:

15-2466

Language:

English

Corporate Authors:

Transportation Research Board

500 Fifth Street, NW
Washington, DC 20001 United States

Authors:

Chai, Gary W
Kelly, Greg
Huang, Tsu-Te (Andrew)
Chowdhury, Sanaul H
Golding, Andrew
Manoharan, Sittampalan

Pagination:

18p

Publication Date:

2015

Conference:

Transportation Research Board 94th Annual Meeting

Location: Washington DC, United States
Date: 2015-1-11 to 2015-1-15
Sponsors: Transportation Research Board

Media Type:

Digital/other

Features:

Figures; References; Tables

Uncontrolled Terms:

Nonlinearity

Subject Areas:

Design; Highways; Pavements; I22: Design of Pavements, Railways and Guideways

Source Data:

Transportation Research Board Annual Meeting 2015 Paper #15-2466

Files:

PRP, TRIS, TRB, ATRI

Created Date:

Dec 30 2014 12:52PM