Analysis and modelling of the seismic behaviour of high ... - Ingegneria

5. SEISMIC BEHAVIOUR OF RC COLUMNS EMBEDDING STEEL PROFILES
one of the goals of the InERD Project is to validate experimentally the joint
mechanisms providing the shear resistance. Hence, once the presumed Joint
Formulation had been derived, we were able to validate it thanks to the
experimental data obtained from the tests.
The inner joint region behaviour is associated with two modes of failure, i.e. Shear
and Bearing Failure and with the two correspondent resisting strengths in shear,
Vjoint,sp and Vjoint,hb, where Vjoint,sp is given by the sum of Vjoint,wsp and Vjoint,ccs. The
outer part of the joint deals with Shear and Bond Failure and with the associated
shear strengths Vjoint,ccf and Vjoint,bf. As a result, the joint inner and outer resistances
are evaluated as follows
and
where
Vjoint,inner = min {Vjoint,ps, Vjoint,hb} ( 5.15 )
Vjoint,outer = min {Vjoint,ccf, Vjoint,b} ( 5.16 )
Vjoint,ps = Vjoint,wps + Vjoint,ccs ( 5.17 )
5.4.1 Strength of the Inner Elements
Inner joint behaviour is characterized by two primary modes of failure. Panel shear
failure, see Figure 5.14a, is similar to the collapse typically associated with
structural steel or reinforced concrete joints; but in composite joints both structural
steel and reinforced concrete elements participate. The bearing failure, shown in
Figure 5.14b, occurs at a location of high compressive stresses and permits rigid
body rotation of the steel column within the concrete beam.
(a) (b)
Figure 5.14. a) Panel shear failure; b) Bearing failure
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