t 

 I 



USEFUL DATA 



Founda- 

 tion 



FOUNDATIONS 

 Bearing Capacity of Soils 



Soil 



Safe Bearing Power in Tons 

 PER Square Foot 



Maximum 



Rock, the hardest, in thick layers in native bed 



Rock equal to best ashlar masonry 



Rock equal to best brick masonry 



Rock equal to poor brick masonry 



Clay in thick beds, always dry 



Clay in thick beds, moderately dry 



[Clay, soft 



Gravel and coarse sand, well cemented . . . 



Sand, dry, compact and well cemented . . . 

 [Sand, clean, dry 



Quicksand, alluvial soils, etc 



30 



20 



10 



8 



6 



2 



10 



6 



4 



1 



Coefficients and Angles of Friction 



Materials in Contact 



Angle of 

 Friction 



Masonry upon masonry 



Masonry upon wood, with grain 



Masonry upon wood, across grain 



Masonry on dry clay 



Masonry on wet clay 



Masonry on sand 



Masonry on gravel 



From "A Treatise on Masonry Construction," by Prof. Ira O. 



33° 00' 

 31° 00' 

 26° 40' 

 26° 40' 

 18° 20' 

 21° 50' 

 31° 00' 



Baker. 



147 



