Laserfiche WebLink
3. Downdrag an be reduced using pile coatings or pre -drilling. <br />Disadvantages <br />1. !)riving noise and vibrations. <br />2. Pile caps needed for pile groups. <br />3. Splicing needed for long piles. <br />4. Equipment and personnel needed for nondestructive toting (in addition to the <br />geotechnial engineer). <br />5.2 CAISSON FOUNDATION <br />5.2.1 Vertical Canockies <br />Caissons should be founded at least 5 feet in':n %t Jai till or outwash. The approximate depth <br />from the existing ground surface to the top of the t, rial materials an shown on Plate g. The <br />depth to the top of till at the existing alosoos along the north wall of the existing building am ab n <br />( included. These depths were obtained by assuming 4 feet of peastration into till. <br />The Straight shaft caissons will derive downward capacity from end burial and skin friction. <br />The latter should be ignored for the fill soil. 4 he caissons may oleo be constructed with bulk <br />formed entirely in till, and will derive downward capacity from end bearing only. Belled caissons <br />should not be considered in the outwash material because of the likelihood of caving of this <br />cohesioniess soil during formation of the bell. <br />s•005.00695.016\ssos0700.aq <br />00695.509.016 8 <br />