Construction of Large Canal on Collapsing Soils

Soil subsidence may occur because of withdrawal of fluids (usually deep subsidence), the drainage of peat lands, or by the application of water to moisure-deficient, low-density soils (usually near-surface subsidence). Only near-surface subsidence is analyzed in connection with the investigations for, and construction of, the San Luis Canal where parts of the alinement passed through areas of low-density, moisture-deficient soils. Ponding of the critical subsidence areas delineated by studies was an effective methods of collapsing and densifying the soils prior to construction of the canal. The canal invert and the embankment were densified with a heavy pneumatic roller during the construction phase. The San Luis Canal was constructed during 1963 to 1968 and has functioned with only minor problems to date (1979).