Then a new concept of physical swelling force was put forward,as its test method.

Strain characteristics of different expansion factors(such as free expansion,confined expansion and effective expansion,etc) and the influential factors are analyzed.

The test results indicate: the beginning water content and dried density of expansive soil are the main outside factors that influence the magnitude of their expansibility and swelling quantity; according to the data of expansibility tests and swelling quantity tests, the variational rule of bot.

Relation between effective stress and swelling stress of coal body;

Experimental research on the swelling stress of limestone in the second coal mine of Tian'an,Pingdingshan city

The characteristic graph of soft rock linear swelling ratio and swelling stress and final water saturation ratio ,and related analysis results of the ratio about mud rock dry saturated absorbed water ratio and the quality contained montmorillobnite are obtained based on a large number swelling experimental results about soft rock are got.

The expansibility, water holding capacity and cation exchange capacity of PDF products were determined .

The shear strength reduction method with FEM is adopted by using the nonlinear and elastoplasticity model of soil,take the effect of the expansibility is taken into account,when the stress and strain of slope body are calculated,which can lead to obtain the distortion process and the latent sliding plane,and the safety factor is adopted to.

The results shows that expansibility,rate of expansion and rate of free expansion of expansive soil changed from originally 111.