Strength and behaviour of deep beams - Reinforced Concrete Deep Beams - page 53

as to withstand the loading as indicated in Figure 2.26 (Leonhardt and
Walther, 1966).
Figure 2.26 Schematic representation of method of transfer of load from bottom to top face of deep
beam.
2.6.3 Verification of design method
The design procedure described has been used to assess the load-carrying
capacity of a large number of deep beams whose behaviour has already been
established by experiment elsewhere (Rawdon de Paiva and Siess 1965,
Ramakrishnan and Ananthanarayana, 1968; Kong et al., 1970; Smith and
Vantsiotis, 1982; Rogowski et al., 1986; Subedi, 1988). The correlations
between prediction and measured values are shown in Figures 2.27 - 2.29.
The investigation covers a wide range of loading conditions including
uniform, single-point, and two-point loading. In most cases, the beams
considered are simply supported (Rawdon de Paiva and Siess, 1965;
Ramakrishnan and Ananthanarayana, 1968; Kong et al., 1970; Smith and
Vantsiotis, 1982; Subedi, 1988); however, the results obtained from work on
continuous deep beams (Rogowski et al., 1986) have also been included.
No distinction has been drawn between beams with and without web
reinforcement as all beams had L/d =2.0 (type IV behaviour) and, as discussed
in section 2.5.3, the effect of such reinforcement on load- carrying capacity
appears to be insignificant. However, the values measured for beams without
web reinforcement exhibit a significantly larger variability.
As indicated in the Figures, the predicted modes of failure are classified
into two types: i) those characterised by failure of the inclined concrete
member of the model (inclined compression failure) and ii) those
characterised by failure of the horizontal concrete member of the model
(flexural failure). For the latter type yielding of the tension steel is assumed
always to have preceded collapse for the cases considered. In general, the
observed modes of failure appear to be in agreement with the predictions,
although those of the observed modes of failure characterised by inclined
cracking are usually reported in the literature as shear or diagonal splitting
failures.