UFC 4-023-03
25 January 2005
6-3
ALTERNATE PATH METHOD FOR MASONRY.
The Alternate Path approach is used to verify that the structure can bridge
over removed elements. Follow the general procedure provided in Section 3-2.
6-3.1
Acceptability Criteria for Masonry.
The acceptability criteria are provided in Table 6-2; calculate the design
strengths per ACI 530-02. The subsequent actions for the AP model after violation of
the acceptability criteria are detailed in the following sub-sections.
Table 6-3 Acceptability Criteria and Subsequent Action for Masonry
Subsequent Action for AP
Structural Behavior
Acceptability Criteria
Model
Φ MnA
Element Flexure
Section 6-3.1.1
Φ PnA
Element Axial
Section 6-3.1.2
Φ VnA
Element Shear
Section 6-3.1.3
Connection Design
Connections
Section 6-3.1.4
StrengthA
Deformation Limits,
Deformation
Section 6-3.2
defined in Table 6-4
A
Nominal strengths are calculated with the appropriate material properties and over-
strength factor Ω; all Φ factors are defined per Chapter 3 of ACI 530-02.
6-3.1.1
Flexural Resistance of Masonry.
For masonry, the flexural design strength is equal to the nominal flexural
strength multiplied by the strength reduction factor Φ. Calculate the nominal flexural
strength per ACI 530-02 procedures.
For Linear Static analysis, if the required moment exceeds the flexural design
strength and if the reinforcement layout is sufficient for a plastic hinge to form and
undergo significant rotation, add an effective plastic hinge to the model, by inserting a
discrete hinge into the member at an offset from the member end. Apply two constant
moments, one at each side of the discrete hinge in the appropriate direction for the
acting moment; see Figure 3-9. Determine the location of the effective plastic hinge
through engineering analysis. For Nonlinear Static and Dynamic Analysis, use software
6-7
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