TABLE OF CONTENTS The following notation is used in this chapter:
| SYMBOL | DEFINITION |
| C A | Adhesion between pier and clay | |
| C s | Coefficient of swell | |
| C s | Swelling index (Fig. 9.12) | |
| e m | Edge moisture variation distance | |
| EI | Expansion index | |
| h i | Initial height of specimen (expansion index test) | |
| h p | Height of specimen at the end of primary swell (expansion index test) | |
| H dr | Swell height | |
| N | Vertical pressure for one-dimensional swell test | |
| P | Pier weight plus dead load applied at the top of the pier | |
| P | Final overburden pressure (Fig. 9.12) | |
| P 0 | Equivalent to P ? s (Fig. 9.12) | |
| P ? s | Swell pressure (Fig. 9.12) | |
| R | Radius of pier | |
| t | Time | |
| T | Time factor (from Table 7.4) | |
| T r | Resisting forces for pier | |
| T u | Uplift force for pier | |
| y m | Maximum anticipated vertical differential movement | |
| Z a | Depth of seasonal moisture change | |
| Z na | Portion of pier below the active zone |
Expansive soils are a worldwide problem, causing extensive damage to civil engineering structures. Jones and Holtz estimated in 1973 that the annual cost of damage in the United States due to expansive soil movement was $2.3 billion (Jones and Holtz, 1973). A more up-to-date figure is about $9 billion in damages annually to buildings, roads, airports, pipelines, and other facilities (Jones and Jones, 1987).
Section 7.4 discussed the consolidation of clay,...
