LABORATORY TESTS ON THREE-DIRECTIONAL SWELLING DEFORMATION OF REMOLDED EXPANSIVE SOIL

This paper studies the characteristic of remolded grey expansive soil in Ningming of Guangxi province. A series of swelling tests were conducted for cubic expansive soil of different initial moisture contents and three-directional pressures. The test device is a home-madethree-directional swelling and shrinkage of expansive soil tester. The tests investigate the natural law of the effects of the initial moisture content and the three-directional pressure to the maximum water content the three-directional expansion rate. According to the test results, the vertical expansion rate is always larger than horizontal expansion rate when three-directional pressure is equal. Their ratio is 1.21～1.27. The ratio is unrelated to the initial moisture content and the three-directional pressure. The time-deformation history of the three-directional expansion rate includes three phases the rapid expansion, the slow expansion and the stabilization. The maximum water content has a linear correlation to the logarithm of the three-directional pressure. But it does not associated with the initial moisture. The three-directional expansion rate has a linear correlation to the logarithm of the three-directional pressure, when the expansive soil has the same initial moisture content and dry density characteristic.