From: Martin Li [mailto:mli@tb-engr.com]
Sent: Thursday, November 08, 2007 4:02 PM
To: seaint@seaint.org
Subject: RE: snow drift and adjacent buildings
The length of upper roof (Lu) should include the separation distance (s). The reduced drift load = [(20 – s) / s] pd.
Martin
-----Original Message-----
From: Alden Manipula [mailto:amanipula@novagroupinc.net]
Sent: Thursday, November 08, 2007 3:23 PM
To: seaint@seaint.org
Subject: snow drift and adjacent buildings
Listers, i have a question regarding snow drifts and adjacent buildings.
Section 7.7.2 of ASCE 7-05 states "The seperation distance, s, between the roof and adjacent structure...shall reduce applied drift loads on the lower roof by a factor of (20s)/20 where s is in ft."
So, w/ Figure 7-8 as a reference, where would s come into play? Would it be added to the length of the upper roof, Lu. Or is it part of the width of the drift, w? Or do i calc the drift as if the building were tight agaisnt each other, as shown in Fig. 7-8, and just reduce the drift load by a factor of s?
Does that make sense to anyone?