Seminar

Dienstag, 18. März 2003
17:00 Uhr, Auditorium HIL E 1
ETH-Hönggerberg, 8093 Zürich
(Lehrgebäude Bauwesen)
Professor Dr. ir.Johan Blaauwendraad Faculty of Civil Engineering and Geosciences TU Delft, NL

Design Tool for Structural Concrete D-regions

Professional engineers apply different stategies in the design of
structural concrete shear-walls, deep beams and distorted beam
parts.World-wide many of them either make use of finite
element programs on basis of elasticity or apply the strut-andtie
method. For both methods pro’s and con’s can be listed.An
alternative approach is advocated which combines advantages
of both approaches and eliminates disadvantage. The proposed
method makes use of just two simple elements: (i) straight
stringers with bundled main reinforcement, (ii) quadrilateral
panels with distributed net reinforcement. The method is
triggered by work of M.P. Nielsen, is based on an equilibrium
state of stress and accounts for nonlinear stiffness
characteristics of the panels (modified compression field theory)
and stringers (eurocode). A fast, PC-oriented, AutoCad-based,
interactive design tool is at disposal that allows the structural
engineer to solve his problem in three subsequent steps. In the
course of this design procedure substantial stress redistribution
is expected to occur. The professional keeps the lead in the
three design steps, has control over crack-width development in
the serviceability state and can make a final check on the failure
load in the ultimate limit state. Some verification and design
examples will be shown.