--ISAP Graduate Student Research Directory

Abstract 

(Summary, conclusions, key achievements)

The main goal of the research is the development of robust algorithm for determining constitutive model parameters and its application to layer moduli back calculation in pavement engineering. Usually, highly sophisticated constitutive model requires many model parameters for predicting material behavior. These parameters are sometimes not easily obtained by simple TX test or field measurement data. The difficulty in parameter estimation is usually caused by model imperfection, stress path dependency of model parameters, noise corrupted measurement data and high correlation among the parameters.

For these reasons, the robust model parameter estimation method is required for the verification of proposed model. One of the recommended methods for parameter estimation is the Kalman Filter. It has been used for state and parameter estimation of static and dynamic system with noise corrupted measurement data since it was first proposed. The Kalman Filter uses statistical updating scheme based on the Bayes theorem. It updates model parameter values from measurement information each iteration step. The structure of Kalman Filter is relatively simple and it is originally design for linear differential equation problems. For this reasons, The Kalman Filter is used for estimating constitutive model parameters of aggregate base material from Laboratory TX data. It is also applied for estimating layer modulie of pavement structure. In pavement engineering, good estimation of layer moduli from nondestructive method is very important for scheduling rehabilitation plan. Although many back calculation methods have been developed, some of them are highly sensitive to initial values and sometimes yield unreasonable results. The Kalman Filter is used for developing new back-calculation method which is not sensitive to initial values.

Starting Date

5 / 2003

Final Completion:

12 / 2006

University
(or institution)

University of California, Berkeley, USA

website: http://www.berkeley.edu

Chair, Civil Engineering

Name: Juan M. Pestana website

e-mail: pestana@ce.berkeley.edu

Student

Jae Woong Choi

e-mail: jaewoong27@hotmail.com

Academic Achievements (degree, grants, publications, etc.)

B.E : SungKyunKwan University, Korea, 3/2000

M.S : University of California, Berkeley, USA, 5/2001

Permission to post on ISAP website
(Members only)

Yes

Date:

10/10/2006