CHAPTER XL 

 STRESSES IN A TRANSVERSE BENT. 



Dead and Snow Load Stresses. The stresses due to the dead 

 load in the trusses of a transverse bent are the same as if the trusses 

 were supported on solid walls. The stresses in the supporting columns 

 are due to the dead load of the roof and the part of the side walls 

 supported by the columns, and are direct compressive stresses if the 

 columns are not fixed at the top. If the columns are fixed at the top 

 the deflection of the truss will cause bending stress in the columns. 

 The dead load produces no stress in the knee braces of a bent of the 

 type shown in Fig. I except that due to deflection of the truss, which 

 may usually be omitted The stresses may be computed by algebraic 

 or graphic methods. 



The stresses due to snow load are found in the same way as the 

 dead load stresses. In localities having a heavy fall of snow the freez- 

 ing and thawing often cause icicles to form on the eaves of sufficient 

 weight to tear off the cornice, unless particular care has been exercised 

 in the design of this detail. 



Wind Load Stresses. The analysis of the stresses in a bent due 

 to wind loads is similar to the analysis of the stresses in the portal of a 

 bridge. The external wind force is taken (i) as horizontal or (2) 

 as normal to all surfaces. The first is the more common assumption, 

 although the second is more nearly correct. For a comparison of the 

 stresses in a bent due to the wind acting horizontal and normal, see 

 Figs. 54, 55, 56 and 57, and Table V. In the discussion which immed- 

 iately follows, the wind force will be assumed to act horizontally. 



The magnitude of the wind stresses in the trusses, knee braces and 



