Developing a model to predict pavement roughness development on expansive soils /
Volumetric change is a property exhibited by expansive soils.
| Main Author: | |
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| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1996.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=743273611&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Volumetric change is a property exhibited by expansive soils. Moisture in expansive soils determines the amount of swell or shfinkage in the expansive soil and is dependent on many factors. Some of these are the climatic environment, the vegetation on the soil, the drainage of the site, the amount and type of clay within the expansive soil, the thickness of the layer of expansive soil and its active zone, and the depth of the water table. As the expansive soil loses moisture, shrinkage occurs and the soil matric generates large negative pore pressure or suction pressure. As a relatively dry expansive soil gains moisture, the suction pressures within are relieved and the soil expands. This dissertation examines the cumulative effects of controlling moisture movement within the subgrade of a pavement by using vertical moisture barriers and how loss of performance on highway pavements built on expansive soils can be managed. Using the moisture balance process of the Thomthwaite Moisture Index the probable maximum, minimum and mean annual moisture depths in an expansive soil subgrade are obtained. The Suction Compression Index (SCI) and the unsaturated hydraulic conductivity and diffusivity are used to characterize the subgrade soil. The SCI of the expansive soil is obtained as a function of the activity of the soil (PI/%fine clay) and the cation exchange activity (CEC/%fine clay). The diffusivity is determined |
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| Item Description: | Vita. "Major Subject: Civil Engineering". |
| Physical Description: | xvi, 182 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references. |