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https://hdl.handle.net/11681/12681| Title: | Field test sections on expansive soil |
| Authors: | Johnson, Lawrence D. |
| Keywords: | Expansive soils Field tests Field investigations Soils Soil mechanics Heaving Soil swelling Swelling soils |
| Publisher: | Geotechnical Laboratory (U.S.) Engineer Research and Development Center (U.S.) |
| Series/Report no.: | Technical report (U.S. Army Engineer Waterways Experiment Station) ; GL-81-4. |
| Description: | Technical Report 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 longterm 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 within 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. Predictions of heave based on a saturated equilibrium moisture profile using suctions measured with thermocouple psychrometers and filter paper provide reasonable overest imates compared to those actually observed at the three test sections. |
| Rights: | Approved for public release; distribution is unlimited. |
| URI: | http://hdl.handle.net/11681/12681 |
| Appears in Collections: | Technical Report |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| TR-GL-81-4.pdf | 7.35 MB | Adobe PDF |  View/Open |