15 AUGUST 2005
settlements to 25.4 mm (1 in) and vibroflot spacing. Allowable pressures for "essentially
cohesionless fills" are less than for clean sand deposits, because such fills invariably
contain some fines and are harder to densify.
Continuous square or triangular patterns are often used over a building
site. Alternatively, it may be desired to improve the soil only at the locations of
individual spread footings. Patterns and spacings required for an allowable pressure of
287 kPa (3 tons per sq ft) and square footings are given in Table 8-7.3.