Expansive rocks in California: An engineering and geologic review

Expansive rocks, also known as swelling or heaving rocks, are present throughout the world and have damaged roads, tunnels, mines, dams, and foundations of commercial industrial and residential development. Knowledge of expansive rocks in the engineering profession is localized and not basic knowledge, although case studies have been recorded since 1928. The fields of engineering geology and rock mechanics have the most knowledge about expansive rock, yet little of this knowledge has crossed over into the civil engineering profession. In California expansive rocks are common. To mitigate this problem, a good understanding of geology must be incorporated into the traditional soil investigation used by geotechnical engineers, in addition to improvements in foundation and pavement design. Expansive rock damage is difficult to monitor because damage develops over years. Through case study review, problems in identifying and mitigating expansive rock are studied and improvements suggested.