Interakce předpjatých základových konstrukcí a podloží

Abstract

The dissertation thesis contributes to the solution of design and assessing of prestressed concrete structures in contact with subsoi1. By inserting a suitable prestress it is possible to improve the static effect of the foundations significantly. Prestressing causes import of bending moments, usually opposite to those caused by the load element. One of the themes of the thesis is the determination of the relative stiffness parameter KR of the prestressed concrete structures and subsoi1. Structural engineer decides on the basis of the parameter value KR, whether the system can be regarded as a yielding or rigid. Standard Eurocode 2 offers guidance for the determination of the relative stiffness parameter KR for no¬prestressed structure but does not specify the influence of prestress to the global stiffness of the foundation. In this artic1e I describe the procedure how to determine the parameters KR through analytical method and for this case also a simple solution that avoids the use of programs running on the basis ofFEM. Influence of contact friction between foundation and subsoil is solved in the following chapters of this dissertation work. These effects were analyzed on the examples of structures based on the subsoil and eccentrically tensioned by a straight cable or parabolic routed cable. Analysis of experimental storage shed in Ostrava Vitkovice is the next part of dissertation thesis. Storage shed was built in the 80's. In the last part of my thesis I have paid attention to the joint free post-tensioned slabs on grade and where it is dealt with losses of prestress due to friction between slab and subsoi1. Traditional solution was compared with FEM analysis on the basis of project documentation.