Field Test Sections on Expansive Soil.
Abstract
This report presents results of field observations at three test sections consisting of 100-ft-square moisture barriers over the surface of in situ swelling soils located near Clinton, Miss.; Lackland Air Force Base, Tex,; and Fort Carson, Colo. Results from more than 5 years of observations show that long-term or progressive heave builds up over many years and tends to be erratic, with most progressive heave accumulating toward the center of the sections. Seasonal or short-term cyclic heave was substantial in the semiarid climate of Lackland and was most noticeable with 10 ft inside and outside of the edge of the 100-ft-square sections. The cyclic seasonal heave exceeded the long-term progressive heave at Lackland. Seasonal heave was not significant at the Clinton test section where a nonswelling overburden overlaid the swelling soil. The amount of heave was strongly influenced by the depth to the water table. The equilibrium pore water pressure profiles obtained for soils taken from beneath the test sections are consistent with pressures between saturated (zero pore water pressure) and negative hydrostatic above the original groundwater level. The large magnitude of the osmotic component of suction observed at the Fort Carson test section had little effect on heave, even after 7 years of observations.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1981
- Accession Number
- ADA100474
Entities
People
- Lawrence D. Johnson