Where:

fr = The modulus of rupture, which is provided in chapter 5.

Yt = The distance from the compression face to the neutral axis of the lintel, inches.

Ig = The moment of inertia of the uncracked lintel cross section about the centroid, in4.

b = The actual width of the lintel, inches.

h = The total depth of the lintel, in.

Icr = The moment of inertia of the cracked section of the lintel, in4.

Values of Icr for most masonry lintels are provided in the tables in appendix B. For continuous members, the

effective moment of inertia may be taken as the average of values obtained from equation 8-1 for the critical

positive and negative moment sections. Ie will not be assumed greater the Ig.

to short term loadings, )ms, (such as live loading and transient dead loadings) combined with the deflections

due to long term dead loadings, )ml, as follows:

)mt = )ms + (3)()ml) (inches)

(eq 8-4)

bearing area, Abrg, will be:

Abrg = 8b (in2)

(eq 8-5)

Fully grouted cores are required below the lintel bearing area. It is reasonable to assume a triangular stress

distribution when determining the maximum bearing stress, fbrg. When this assumption is made, the maximum

bearing stress occurs at the face of the support and is determined by the following equation:

Where:

Rbrg = The end reaction of the lintel, lbs.

The maximum bearing stress will not exceed the allowable bearing stress, which is given in chapter 5. If the

lintel is restrained against rotation at the support, a uniform stress distribution will be assumed.

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