Project:   Validation of Advanced Analytical Tools for Geotechnical applications

PI(s):  Pedro Arduino

Sponsor:  University of Washington

Problem/Description:   To date, many numerical tools have been proposed for the analysis of geotechnical problems. They vary from simple limit equilibrium applications to more advanced finite elements and finite differences codes. Traditionally, geotechnical design has strongly relied on limit equilibrium tools. In contrast, finite element codes have been limited to special projects mainly due to difficulties handling the codes and determining appropriate modeling parameters. However, the state of the art in finite elements programs has significantly changed since the finite element method was originally introduced. Today, codes are much easier to use, are usually integrated with efficient graphical interfaces, and are more reliable and robust. Today several codes are available with special emphasis on geotechnical engineering. With them it is possible to consider problems that can not be solved using traditional methods. The prediction of the reduced capacity of piers due to structural and geometric defects and the response of retaining walls under seismic excitations are examples of geotechnical scenarios that require further attention and more refined analytical tools.

Proposed Research Approach: In this context, this research project envisions to reduce the gap between new analytical tools and what is currently used in geotechnical practice. Special attention will be given to the validation of selected numerical tools (e.g. FLAC and PLAXIS) and the development of templates that could be utilized or modified for further analyses. Specific geotechnical problems will be used (but not limited) as target scenarios for this study. The proposed research would include the following tasks:

1- Evaluation of selected analytical codes for the practical analysis of geotechnical problems: PLAXIS and FLAC will be evaluated and their capabilities to study geotechnical problems in practical ways will be assessed. Simplicity in defining the model, required material parameters, loading history, and accuracy of the results will be used as target variables. Validation of the selected analytical tools: Comparison of numerical predictions to measured full scale and model performance. This task will help build confidence in the accuracy of the codes and to determine the best way to apply them.

2- Target Problems: Several problems of special interest for Washington DOT will be considered:

A- Prediction of reduced capacity due to shaft defects.

B- Seismic behavior of retaining walls and other structures (i.e., improve M-O method for wall design in larger EQ's).

3- Development of design templates: This task would include the development of templates and approaches to make application of these tools consistent and easier.

Potential Benefits:   The research will provide improved understanding on the practical use of advanced analytical tools for geotechnical problems. It will also provide improved understanding on the seismic behavior of retaining walls, and effects of defects on piers capacity. The development of design templates will help in the applicability of the research findings.

For more information send E-Mail to: parduino@u.washington.edu