Civil Engineering Reference
In-Depth Information
studied by Cusens and Besser (1985) and, less systematically, by a few
others earlier (CIRIA, 1977). Rogowsky
et al,
(1986) carried out extensive
tests on
continuous deep beams,
which is the subject of Chapter 4. Mau
and Hsu (1987) applied the
softened truss model theory
to deep beams; see
Chapter 7 for details. Kotsovos (1988) studied deep beams in the light of a
comprehensive investigation into the fundamental causes of shear failure;
Chapter 2 gives further details.
The major contributions of other active workers are referred to elsewhere
in this volume; mention need only be made here of Barry and Ainso (1983),
Kubik (1980), Mansur and Alwis (1984), Regan and Hamadi (1981),
Rasheeduzzafar and Al-Tayyib (1986), Roberts and Ho (1982), Shanmugan
(1988), Singh
et al.
(1980), Smith and Vantsiotis (1982), Subedi (1988), and
Swaddiwudhipong (1985).
With reference to Chapter 8, plastic methods have valuable applications
in structural concrete. However, their more general acceptance has probably
been hindered by the widespread confusion over the
fundamental plastic
theorems
themselves (Kong and Charlton, 1983). For example, the plastic
truss model proposed by Kumar (1976) could be shown to violate the
lower
bound theorem
(Kong and Kubik, 1977). The difficulties are unlikely to be
overcome until the currently widespread misunderstanding of the principle
of virtual work can somehow be cured (Kong
et al.,
1983b).
1.3
Current design practice
The subsequent sections of this chapter will summarise the main design
recommendations of: the CIRIA Guide 2, the (draft) Eurocode and the
CEBFIP Model Code, the ACI Code 318-83 (revised 1986) and the
Canadian Code CAN-A23.3-M84
1.4
CIRIA Guide 2
The CIRIA Guide (CIRIA, 1977) applies to beams having an effective span/
depth ratio
l/h
of less than 2 for single-span beams and less than 2.5 for
continuous beams. The CIRIA Guide was intended to be used in conjunction
with the British Code CP110:1972; however, the authors have done some
comparative calculations (Kong
et al.,
1986) and believe that the CIRIA
Guide could safely be used with BS 8110:1985.
The Guide defines the
effective span l
and the
active height h
a
as follows
(see meanings of symbols in
Figure 1.2.
)
l
=
l
o
+[lesser of (
c
1
/2 and 0.1
l
o
]+[lesser of (
c
2
/2) and 0.1
l
o
]
(1.1)
h
a
=
h
or
l
whichever is the lesser
(1.2)
