Seismic Pavement Analyzer vs. Falling Weight Deflectometer for Pavement Evaluation: Comparative Study

Abstract

The purpose of using nondestructive testing techniques (NDT) for pavement evaluation is to obtain material properties at relatively low strain levels. Backcalculation methods that utilize surface deformation such as falling weight deflectometer (FWD) and Dynaflect assume linear elastic modeling for the pavement layers. Although the same assumption was considered for the seismic pavement analyzer (SPA) method, results obtained from these testing techniques did not conform to each other. To narrow the gap between the obtained pavement moduli values, a total of 22 pavement sites have been tested in Florida using deflection and seismic methods. Using the time-history records as well as the frequency response functions, pavement deformations from deflection and seismic methods were measured and related to the obtained moduli values. Relationships between deformation vs. pavement stiffness are presented. These relationships can be used to extract moduli values at any level of pavement deflection.

Advanced Approaches to Characterizing Nonlinear Pavement System Responses

“…The use of backcalculation techniques based on nondestructive testing (NDT) to determine layer moduli is a cost-effective and widely used method for the structural evaluation of an existing pavement. Among all NDT methods, the falling weight deflectometer (FWD) is probably the most widely used technique because of its ability to successfully simulate traffic loadings and its capacity to produce a larger amount of deflection data in unit time (1)(2)(3)(4).…”

Determination of Deflection Basin Using Pavement Modelling Computer Programs and Finite Element Method

“…In FWD test, an impulse load is applied to pavement surface by dropping a mass weight onto a circular plate with a rubber seal placed between the plate and pavement surface to prevent direct impact of the load. Surface deflections are measured directly below the plate by using several sensors or geophones at different radial offsets [2][3][4][5]. One major use of the FWD data is for performing back-calculation analysis [6,7].…”