01026065

Component

Compacted soils are extensively used in engineering projects and the volume change of compacted soils is of great interest to engineers. Most compacted soils have collapsible soil behaviors when subjected to wetting or loading. Volume change of compacted soil is therefore a consolidation problem for unsaturated collapsible soils. At present the existing consolidation theory for unsaturated soils is based on the assumption that the soil is elastic while unsaturated soils are well-known elastic-plastic materials. In addition, there is no method available to calculate the excess pore water pressure for unsaturated soils under undrained conditions (constant water content only). Consequently, the consolidation of unsaturated soils still remains unsolved. This paper proposes a method to calculate the excess pore water pressures under undrained loading by considering compacted soils as elastic-plastic materials. Based on the calculated excess pore water pressure, a method is proposed to calculate the one dimensional consolidation for collapsible soils. Analytic solutions of excess pore water pressure (matric suction), immediate, consolidation, and total settlements during the consolidation process can be obtained. The proposed theory can also be used for unsaturated collapsible soils when the loading is isotropic. A real collapsible soil with measured constitutive surfaces is used to illustrate the proposed theory. Some problems related to the consolidation of unsaturated collapsible soils are also discussed in the paper.

01020180

06-2644

English

19p

2006

Transportation Research Board 85th Annual Meeting

CD-ROM

Figures (6) ; References (10) ; Tables (2)

Collapsible soils; Compacted soils; Consolidation; Engineering; Isotropy; Pore water pressures; Unsaturated soils; Volume changes

Undrained soils

Geotechnology; Highways; I42: Soil Mechanics

Transportation Research Board Annual Meeting 2006 Paper #06-2644

TRIS, TRB

Mar 3 2006 11:05AM