TABLE OF CONTENTS Soil for foundations can be altered to conform to desired characteristics. Whether this should be done depends on the cost of alternatives.
Investigations of soil and groundwater conditions on a site should indicate whether soil improvement, or stabilization, is needed. Tests may be necessary to determine which of several applicable techniques may be feasible and economical. Table 7.19 lists some conditions for which soil improvement should be considered and the methods that may be used.
| Soil Deficiency | Probable Type of Failure | Probable Cause | Possible Remedies |
|---|---|---|---|
| Slope instability | Slides on slope | Pore-water pressure | Drain; flatten slope; freeze |
| Loose granular soil | Compact | ||
| Weak soil | Mix or replace with select material | ||
| Mud flow Slides movement at toe | Excessive water | Exclude water | |
| Low bearing capacity | Excessive settlement | Saturated clay | Consolidate with surcharge, and drain |
| Loose granular soil | Compact; drain; increase footing depth; mix with chemicals | ||
| Weak soil | Superimpose thick fill; mix or rei place with select material; inject or mix with chemicals; freeze (if saturated); fuse with heat (if unsaturated) | ||
| Heave | Excessive rise | Frost | For buildings: place foundations below frost line; insulate refrigeration-room floors; refrigerate to keep ground frozen |
| For roads: Remove fines from gravel; replace with nonsusceptible soil | |||
| Expansion of clay | Exclude water; replace with granular soil | ||
| Excessive Permeability | Seepage | Pervious soil or fissured rock | Mix or replace soil with select material; inject... |
