California Housing Damage Related to Expansive Soils

Abstract

Differential movements of foundations on expansive soils have caused damage to thousands of homes in California. Building damages or just out-of-level floors have resulted in widespread claims and repair expenses. This paper discusses historical and environmental conditions which have led to these problems in California. It describes the current state-of-the-art in foundation design and construction methods used to minimize movements, characterizes out-of-level conditions, and recommends tolerances to assist in evaluating the performance of residential structures. The authors conclude with a summary of considerations and comments on how some of the barriers to upgrading professional engineering practice relative to expansive soils might be overcome.