Tunnel face stability by Transformation Field Analysis and Distinct State concept

 

Grant No.:

103/03/0483

Grant Agency:

Czech Science Foundation (GAČR)

Resolved in:

2003 - 2005

Principal investigator:

Petr Procházka, Czech Technical University in Prague, Faculty of Civil Engineering

Co-investigators:

Kamila Weiglová, Brno University of Technology, Faculty of Civil Engineering
Ivan Kameníček, INSET s.r.o., Praha
Jiřina Trčková, Department of Seismotectonics, IRSM AS CR, v.v.i.

Description:

Eigenstresses and eigenstrians act out a very important role in many branches of applied mechanics. The eigenparameters may represent plastic strains or relaxation stresses (or also prestress, change of temperature, etc.), and may serve as free parameters for improving properties of numerical models to get the computed quantities that should be as close as possible to the real state. In order to get a reasonable agreement between these quantities when comparing both computed and measured values, a special variation formulation can be given, dealing with the minimum variance of differences between measured and computed values. Using a very useful treatment, transformation field analysis (TFA), having recently been proposed by Dvorak & Procházka, the problem leads to a linear system of algebraic equations. In the case of this grant project we start with distinct state concept (DSC) having been proposed by Desai and describing nonlinear material behavior of the rock. The concept das not consider elastic original states any longer (it ranges from plastic, viscoplastic and damage behavior of the rock). The starting stage if then “tuned” by eigenparameters and hence, the nonlinear material properties are obtained in both scale and numerical models.

ISVAV: (What is it?)

Project in The Research and Development and Innovation System of the Czech Republic (in Czech only)