USEFUL DATA 



The disposition of the reinforcing steel is indicated in the cuts at the head of the table. 



Where soil conditions are of such a nature that spread footings cannot be used, 

 resort must be had to piles of either wood or concrete. If the piles are cut off below 

 the low water line, wooden piles may be used, but if exposed to alternate wet and dry 

 conditions wood is subject to rot and concrete piles should be employed. The tables of 

 pile caps given on pages 141 and 142 are designed for concrete piles having an assumed 

 carrying capacity of 30 tons per pile. The style and reinforcement of cap and num- 

 ber of concrete piles required are determined from the tables, when the column load is 

 known. 



Designs for concrete piles of the pre-cast type are given in the table on page 143. 

 Except under the most adverse conditions as regards surface and sub-soil, a load of 

 30 tons per pile may be safely used and if the piles are driven to rock a 50% increase 

 m load should be permissible. The amount of reinforcement used is considered a 

 minimum consistent with successful handling of the pile from the casting yard to its 

 place in the work. 



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