Roof Wall Diaphram

Main features roof diaphragm design example.

Roof wall diaphram.

Assuming a flexible roof diaphragm determine the forces in walls a b c and d for north south loading. The maximum average shear r b occurs at the ends of the roof diaphragm. The roof structure consisting of the roof framing roof decking sheathing and any internal bracing also functions as a horizontal diaphragm and transfers the horizontal loads. The diaphragm forces tend to be transferred to the vertical resisting elements.

So how has this generally conventional roof diaphragm design example discovered its way into present day engineering. The roof and foundation support the vertically spanning wall and consequently pick up the developed horizontal reactions. 2 design example 2 n flexible diaphragm design the uniform loads w 1 and w 2 in the east west direction are computed using the diaphragm lengths and wall heights. Zones near the mid span of the roof are subjected to less unit shear therefore less.

In structural engineering a diaphragm is a structural element that transmits lateral loads to the vertical resisting elements of a structure such as shear walls or frames diaphragms are typically horizontal but can be sloped such as in a gable roof on a wood structure or concrete ramp in a parking garage. Roof dead load 14 psf. Side wall carries load to roof diaphragm at top and to foundation at bottom roof horizontal diaphragm carries load to end walls end wall vertical diaphragm or shear wall carries load to foundation v lb per lin ft of diaphragm width w lb per lin ft of wall f t lb c vh h 2 wl 2b wind load lb per sq ft figure 1. The roof diaphragm design example has for some time been a piece of customary structural history.

Because this building has one story assume that the seismic weight is concentrated at roof level. Roof framing and 3 adequate connections between the roof structure and the top of the wall to create a complete vertical load path. Request that any youngster draw a house and theyll draw a house with a peak roof. 134 2015 ibc seaoc structural seismic design manual vol.

Wood frame structural panel diaphragms shall be designed and constructed in accordance with af pa sdpws where panels are. Also assume the mass is evenly distributed over the entire roof. At the roof level these wall reactions turn the load in the roof system in the plane of the roof. A diaphragm acts like a short deep beam.

This horizontal element is known as the diaphragm.