An experimental study of three-dimensional swelling pressure of Hefei remolded expansive clay

This paper studies the characteristics of Hefei remolded expansive clay. A series of three-dimensional swelling tests is conducted on cubic expansive soil of different initial moisture contents and dry densities. For the specimens investigated in this study, three-dimensional swelling pressures are unequal. The vertical swelling pressure is larger than lateral swelling pressure. The period of the rapid expansion is about 0-2 h; the vertical swelling pressure can reach more than 80% of the limit swelling pressure. Secondly, under the same dry density, the vertical swelling pressure decreases with the rise of initial moisture content; and there is a good linear relationship between these two elements. Meanwhile, with the increase of dry density, the rate of change between them also rises correspondingly. Furthermore, the graph of the relationship between the vertical swelling pressure and dry density illustrates that each curve presents bilinear relation based on the segmentation point which is dry density of 1.6 g/cm(3). At last, from the graph of the relationship between the logarithm of swelling pressure and initial dry density, it can be seen that the relationship of ln(P-z)-rho(d) under different initial moisture contents displays a series of approximately paralleled and incremental straight line. And the similar slopes, of these lines demonstrate that the rate of change between swelling pressure and the initial dry density dose not change with the variation of moisture content.