In order to investigate the volume change behaviour of compacted expansive soil

the one-dimensional swelling- compression tests are carried out for Jingmen weak expansive soil associated with six different compactnesses. Based on the results of one-dimensional nonloaded swelling tests

a time-swelling formula is presented which can fit the tested time-swelling curve satisfactorily with the physically meaningful parameters. Furthermore

the time-swelling curve can be characterized as three segments divided by a method presented. On the other hand

the results of the one-dimensional compression tests are used to investigate the interactive relationship between consolidation yield stress

compression index Cc

swelling index Cs

swell pressure and sample compactness

soil structure

swelling potential

void ratio in detail. The test results show that the volume change of compacted expansive soil is the consequence of the effects coupled moisture

external load

and swelling potential. And the volume change depends heavily on the hydro-mechanical path.