Analysis and Performance of the NATM Excavation of an Underground Station for the Athens Metro

The paper describes the design methods and summarises the results of the analyses for the recent NA TM excavation of an underground station of the Athens Metro. The non-linear finite element calculations show that for the excavation method used (twin side-wall galleries and a central pillar), the settlements at ground surface are very sensitive to the assumed values of the ground properties as well as the excavation sequence and construction details; it is shown that the settlements can be reduced significantly by increasing the number of the excavation stages and the density of the temporary support measures

La boîte à outils géotechniques de demain: EN 1997-1: 202x Règles générales

This paper describes the development of the final Project Team (PT) draft of the next generation of Eurocode 7 Part 1 (EN 1997-1:202x). The use of Nationally Determined Parameters and the drive for ease-of-use is highlighted. Key changes from the previous version of EN 1997-1 are explained, including the introduction of the Geotechnical Design Model; revision of the Geotechnical Categories and their application; the implementation of Consequence Classes and Geotechnical Complexity Classes in achieving the reliability required by the Eurocodes; elaboration on the use of numerical methods within Eurocode 7; the treatment of rock on an equal basis with soil; and greater emphasis on the Observational Method.Postprint (published version

Non-linear consolidation around driven piles in clays

Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1982.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING.Bibliography: leaves 544-558.by Michael Kavvadas.Sc.D

Stress-strain models for soils based on plasticity theory

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1980.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING.Bibliography: leaves 151-155.by Michael Kavvadas.M.S

A Constitutive Model for Unsaturated soils based on a Compressibility Framework dependent on Suction and Degree of Saturation

The Modified Cam Clay model is extended to account for the behaviour of unsaturated soils using Bishop’s stress. To describe the Loading – Collapse behaviour, the model incorporates a compressibility framework with suction and degree of saturation dependent compression lines. For simplicity, the present paper describes the model in the triaxial stress space with characteristic simulations of constant suction compression and triaxial tests, as well as wetting tests. The model reproduces an evolving post yield compressibility under constant suction compression, and thus, can adequately describe a maximum of collapse