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Low LOP Progressive Collapse Horizontal Ties

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Can someone please clarify the requirements for 'horizontal ties to external walls and columns' in UFC 4-023-03 (Progressive Collapse).  The examples in the Appendix don't seem to match the requirements. 

 

Section 7-2.6 requires horizontal ties at "each external column and, if the peripheral tie is NOT located within the wall."  It goes on to require horizontal ties "at each floor and roof level"

 

Section 7-2.4 requires internal ties "must be anchored to peripheral ties"

 

The result, in a bearing wall if the peripheral tie is in the wall, only internal ties are required (no horizontal ties), as shown in in the example in Appendix F.  However, the example only addresses the top of an exterior wall.  At the bottom of the wall there is no peripheral tie in the wall, so based on Section 7-2.6 a horizontal tie is required at the floor level.  In all of the design examples I have seen the bottom of the wall is not addressed.  Am I misreading this requirement?  Is a horizontal tie required at both the top and bottom of each exterior bearing wall?

 

And, if it is to be "anchored or tied horizontally" how is this being achieved with a strap, as shown in the examples, when a strap would provide no resistance in the horizontal direction?

 

Thanks in advance,

 

Eric Tompos, PE