This paper presents a hybrid model based on the displacement back analysis to estimate the earth stress magnitude and direction from the obtained borehole displacements. An artificial neural network (ANN) is used to map the non-linear relationship between the maximum horizontal earth stress, σH, the minimum horizontal earth stress, σh, the direction of the largest horizontal earth stress, θ and the borehole displacements. The genetic algorithm (GA) is used to search the set of unknown earth stresses and direction according to the objective function. Results of the numerical experiments show that the displacement back analysis method can effectively identify the earth stress based on the wellbore motions during drilling. and Obsahuje seznam literatury
The techniques of the method of the coupled modelling was substantially extended and used for solving problems connected with underground constructions for various materials and appropriate structural systems. In principle, a combination of linear effects of the external loading and material and time-dependent nonlinear change in structures was considered. Assessment of rock behaviour in surrounding of utility tunnels, solution of the structural strength below foundation, back analysis of reinforced soil slopes and studies of slopes endangered by groundwater were carried out., Petr Procházka and Jiřina Trčková., and Obsahuje bibliografii