

and 



CONTINUOUS BEAM 



5 



ii 



i6 7 



Beam Uniformly Loaded. In (a) Fig. 7, a continuous beam 

 of three equal spans of length L, is loaded with a uniform load equal 

 to w per foot. Calculate the bending moments due to a uniform load 

 of w on each span, and load a simple beam of span 3 L with the posi- 

 tive bending-moment diagrams due to load w, and with the negative 

 bending-moment diagrams due to the reactions R 2 and R 3 . The 

 bending moment M 2 is equal to M 3 . Now the deflection of the beam 

 is zero at 2 and 3, and the bending moments must, therefore, be zero 

 at these points. Taking moments of forces to the left of 2, we have 



FIG. 7. 



wL 4 wL 4 M 2 L 2 



M 2 L 2 -H =o 



8 24 6 



wL 2 



10 

 To calculate R take moments about 2 in (a), and 



2 



4_ 

 10 



