BEARING POWER OF SOILS 



2 73 



TABLE XXIII. 



SAFE BEARING POWER OF SOILS.* 



When foundations are placed on solid rock, the surface of the 

 rock should be carefully cleaned of loose and rotten rock and roughly 

 brought to a surface as nearly perpendicular to the direction of the 

 pressure as practicable. A layer of cement mortar placed directly on 

 the rock surface will assist in bonding the foundations and the footing 

 together. 



When foundations are placed on sand, gravel or clay it is usually 

 only necessary to dig a trench and start the foundation below frost. If 

 the soil is somewhat yielding or if the load is heavy the foundation 

 should be carried to a greater depth or the footings should be made 

 wider than for greater depths. 



Bearing Power of Piles. Probably no subject has been more 

 freely discussed and with more conflicting views and opinions than has 

 the safe bearing power of piles. The safe load to put on a pile in any par- 

 ticular case is dependent upon so many conditions that any formula for 

 the safe bearing power is necessarily simply an aid to the judgment 

 of the engineer, and not an infallible rule to be blindly followed. All 



*Treatise on Masonry Construction, by Ira O. Baker, John Wiley & Soas, 

 Publishers, New York. 



