1. ABOUT ESTIMATION OF EROSION AND REFORMATION OF BANK VAULTS OF GROUND CHANALS AND CANALS

SH. GAGOSHIDZE, T. LORDKIPANIDZE
(Georgia)

Approximation theory of the motion of the alongshore wave in a canal communicting with sea is reviwed and a method for estimating deformability of its bank vaults is drafted. One of the most characeristic features of the alongshore waves is an increase of their height close to its bank line. This feature in relief is reflected in an accurate solution of Stokes yet relating to just the waves on the bank vaults infinitely going deep into the sea. For the canals with finite depth and closed contour (in particular, for trapeziod canals) the method of interfacing the solutions of the wave equations written in cylindrical and Cartesian rectangular coordinates respectively for the areas confined with the bank vaults and horizontal bottom of the canal is used.



2. EXPERIMENTAL RESEARCH OF PRE-STRESSED REINFORCED-CONCRETE BODY OF NUCLEAR STATION REACTORS

A. KUBANEISHVILI, A.IURATIN
(Georgia)

The experimental part of the work involves both vessel body model and its components' testing to solve structural and technological problems. On the structural components of the roof (floor) and the wall as well as on confined vessel model the issues were being studied concerning the distribution of stresses from various forces ocuuring both separately and in combination.

- on specimens in a shape of circular disk (roof) from the action of prestressed tendons;
- on a compound wall of cylindrical shells from the pressure of the cement grout injected into the gap in between as well as from the action of the internal working pressure.

On the vessel wall component, the technology of cement grout injection into the gap was being tested, preliminary testing being carried out with cylindrical specimens.



3. CONSTITUTIVE MODEL FOR CONCRETE IN PLANE STRAIN CONDITION AND IT’S APPLICATION TO THE ANALYSIS OF A GRAVITY DAM1

M.RAOOF, Dr G.MAZZA, A.MOTSONELIDZE, V.ABULADZE
(Great Britan, Italy, Georgia, Georgia)

The non-linear behaviour of a gravity dam is usually analysed, within the plane strain condition, by assuming that the stress-strain relationships in the directions of principal stresses follow the non-linear uniaxial constitutive relation. However, it is now well-established that the non-linear biaxial constitutive relations for concrete differ significantly from the non-linear behaviour of concrete under uniaxial loading conditions (Kupfer et al. 1969, Kupfer 1973, Tasuji 1976, etc.). It is therefore, desirable to employ a non-linear biaxial constitutive relationship for concrete, when analyzing various structural characteristics of a gravity dam. However, it is a point of concern that the previously reported non-linear biaxial constitutive relationships for concrete deal, almost entirely, with the plane stress condition, and that there is currently a lack of theoretical and experimental data dealing with the plane strain condition. Development of a non-linear biaxial constitutive relationship for concrete subjected to the plane strain condition is, therefore, desirable for analyzing the stress conditions within the body of a gravity dam (amongst other plane strain problems).