Numerical Methods to Model Excavation of Soil Adjacent to Retaining Structures

摘要

The U.S. Army Corps of Engineers uses SOILSTRUCT-ALPHA to perform soil-structure interaction (SSI) analyses of multi- anchored or tieback retaining walls. A critical aspect for SSI analyses of such structures is the modeling of the excavation process. The excavation algorithm in SOILSTRUCT was developed in the late l960s by Clough and Duncan (1969), and it has not been updated since that time, even though improved methods have become available. In this investigation, a comprehensive literature review of numerical modeling of excavation was performed to determine the suit- ability of existing excavation algorithms for their use in SOILSTRUCT. It was shown that the existing Clough and Duncan excavation procedure used in SOILSTRUCT-ALPHA yields results that are dependent on the number of excavation stages used in the simulations for linear elastic materials. Of the general methods reviewed, the most appropriate method for implementation, and recommended for implementation in SOILSTRUCT-ALPHA, is the method of force residuals. Information necessary to implement this excavation algorithm in SOILSTRUCT-ALPHA is given in the report.