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Abstract

This diploma thesis investigates the analysis and design of gravity retaining walls. More specifically, it aims at: a) developing a complete numerical tool in excel spreadsheet to analyze and design both in geotechnical and structural engineering terms and b) to compare the Rankine earth pressures analysis with the numerical finite element analysis (FEA) results for a range of soil types. Chapter 1 presents the advance of Retaining Walls throughout the human history and the types which we construct today. Chapter 2 describes and presents the regulation of the analysis and design of gravity walls in Europe – Eurocode 7(EC7). Next, Chapter 3 presents the theoretical framework about the earth pressures which is the basis of the analysis of a retaining work. Chapter 4 describes the types of Concrete Retaining Walls and their failure behaviors. Moreover, in Chapter 5 an excel sheet was successfully programmed for the complete conventional analysis and design of a reinforced concrete retaining wall (Type L) with load on the backfill . Chapter 6 involve extensive numerical modeling on a range of non-cohesive sands and cohesive clays scenarios with FEA, using a linear elastic – perfectly plastic Mohr Coulomb constitutive model. In Chapter 7, a comparison of the earth pressures calculated with the Rankine method and the FEA for sands and clays for a concrete gravity wall, is presented. The FEA included the complete structure sequence. The main conclusion is that Rankine method underestimated the soil earth pressures as in FEA there was no generalized soil failure, which depends on soil strength (c΄, φ΄). As a result, soil movements were lower than expected for Rankine failure. Elasticity modulus (E) had little on earth earth pressures because Poison’s ratio is the main influential parameter.