Inverse Analysis of Deep Excavation Using Differential Evolution Algorithm

• Published in: International journal for numerical and analytical methods in geomechanics Vol. 39; no. 2; pp. 115 - 134
• Main Authors: Zhao, B. D., Zhang, L. L., Jeng, D. S., Wang, J. H., Chen, J. J.
• Format: Journal Article
• Language: English
• Published: Bognor Regis Blackwell Publishing Ltd 10.02.2015; Wiley Subscription Services, Inc
• Subjects: Algorithms; Cam-clay model; Computer programs; Deflection; differential evolution; Excavation; excavations; Finite element method; inverse analysis; Mathematical analysis; Mathematical models; optimization algorithms; Soil (material); Soil analysis; Walls; Taiwan, Taipei
• ISSN: 0363-9061; 1096-9853; 1096-9853
• DOI: 10.1002/nag.2287

Summary This paper presents the applications of the differential evolution (DE) algorithm in back analysis of soil parameters for deep excavation problems. A computer code, named Python‐based DE, is developed and incorporated into the commercial finite element software ABAQUS, with a parallel computing technique to run an FE analysis for all trail vectors of one generation in DE in multiple cores of a cluster, which dramatically reduces the computational time. A synthetic case and a well‐instrumented real case, that is, the Taipei National Enterprise Center (TNEC) project, are used to demonstrate the capability of the proposed back‐analysis procedure. Results show that multiple soil parameters are well identified by back analysis using a DE optimization algorithm for highly nonlinear problems. For the synthetic excavation case, the back‐analyzed parameters are basically identical to the input parameters that are used to generate synthetic response of wall deflection. For the TNEC case with a total of nine parameters to be back analyzed, the relative errors of wall deflection for the last three stages are 2.2, 1.1, and 1.0%, respectively. Robustness of the back‐estimated parameters is further illustrated by a forward prediction. The wall deflection in the subsequent stages can be satisfactorily predicted using the back‐analyzed soil parameters at early stages. Copyright © 2014 John Wiley & Sons, Ltd.