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PROCEEDINGS OF THE ELEVENTH INTERNATIONAL CONFERENCE ON CIVIL, STRUCTURAL AND ENVIRONMENTAL ENGINEERING COMPUTING
Edited by: B.H.V. Topping
Interaction Modelling for Earth Retaining Structures using Evolutionary Computation
M.A. Demarzo1 and M. Tacitano2
1Department of Structures, Faculty of Civil Engineering, Architecture and Urbanism, State University of Campinas, UNICAMP, Brazil
M.A. Demarzo, M. Tacitano, "Interaction Modelling for Earth Retaining Structures using Evolutionary Computation", in B.H.V. Topping, (Editor), "Proceedings of the Eleventh International Conference on Civil, Structural and Environmental Engineering Computing", Civil-Comp Press, Stirlingshire, UK, Paper 15, 2007. doi:10.4203/ccp.86.15
Keywords: earth-retaining walls, evolutionary calculation, soil-structure interaction, Winkler model, non-linear modelling.
Guerra  and Marzionna  affirm that the earth-retaining structures can be analysed by empirical methods (based on experimental results), semi-empirical methods, and analytical methods (evolutionary calculations). The last approach is represented by one-dimensional methods (Winkler Model) as well as bi-dimensional or tri-dimensional. For the calculation objectives, without conflicting with this classification, it is still possible to divide the earth-retaining walls into: cantilever walls; walls with only one support level; walls with two or more support levels. For both cantilever walls and those with only one support level, it is possible to assume that the state of stress in the retained soil is such that the plastic limit condition is always reached. Therefore, the dimensioning is done using the Rankine theory. On the other hand, in the case of two or more support levels, the active state is not totally mobilized in the retained soil, nor the passive state from the inside of the retaining wall. For this reason, other hypotheses are necessary.
In this paper a calculation method is demonstrated (analytical one-dimensional method based on the Winkler Model). An implementation is developed by a trench calculation evolutionary program, called CEDEVE, in which it is possible to consider several excavation phases, producing both displacements and internal forces at its elements, besides admitting the variation of a series of properties of the soil and walls . Then, this work makes comparisons with the results from the proposed method, with others that adopt similar hypotheses of construction, as well as semi-empirical methods. Although the one-dimensional analytical method is not a new method, Negro and Leite  expressed the need to make it available to the technical environment. A detailed description of the calculation method and CEDEVE program are given in Tacitano . Two examples carried out with CEDEVE are presented and comparisons with other existing programs are made.
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