280 FOUNDATIONS 



Piles driven in firm soil to rock may be loaded to the above limits. 

 Piles driven through loose, wet soil to solid rock or equivalent bearing 

 shall be figured as columns with a maximum unit strain of 600 Ibs. per 

 sq. in., properly reduced. 



The minimum distance between centers of piles shall be 2,y 2 ft. 



5. Loads on Foundations. The live loads on foundations shall 

 be assumed to be the same as for the footings of columns. The areas 

 of the bases of the foundations shall be proportioned for the dead load 

 only. That foundation which receives the largest ratio of live to dead 

 load shall be selected and proportioned for the combined dead and 

 live loads. The dead load on this foundation shall be divided by the 

 area thus found, and this reduced pressure per square foot shall be 

 the permissible working pressure to be used for the dead load of all 

 foundations. 



6. Reduction of Live Load on Columns. For columns carry- 

 ing more than five floors, these live loads may be reduced as follows : 



For columns supporting the roof and top floor, no reductions; 



For columns supporting each succeeding floor, a reduction of 

 5 per cent of the total live load may be made until 50 per 

 cent is reached, which reduced load shall be used for the 

 columns supporting all remaining floors. 



