Study On Disintegration Mechanism Of Variegated Clay

The disintegration of the soil on the slope will significantly affect the permeability of the soil slope,change the hydrological conditions of the slope and then affect the stability of the slope.At the same time,the products of slope soil disintegration will also become an important source material for debris flow disasters.Combining with heavy rainfall conditions can induce mountain debris flow disasters.It is necessary to carry out scientific research on the mechanism of soil disintegration in order to reduce the damage caused by the disintegration of sloped soil.Firstly,an outdoor disintegration test was carried out on the test of exposed variegated clay in Shanxi Wuxiang,and the influence of the sample boundary conditions on its disintegrability was analyzed.Secondly,the disintegration test under different test conditions was carried out by the improved indoor soil disintegration tester.The effects of initial moisture content,dry-wet cycle,temperature,material composition,and sample size on the disintegrability of mottled clay were mainly analyzed.The correlation between the microstructure characteristics of the variegated clay and its disintegration characteristics was analyzed based on the results of microstructure experiments.The mechanism of softening and disintegration of variegated clay in the study area was analyzed.The following conclusions were reached:(1)The field disintegration test results show that the original sample in the study area has weak disintegration ability.Analysis of the disintegration test results of samples with different initial moisture content in the room shows that the mottled clay samples with high moisture content are difficult to disintegrate and break in water.However,low water content samples can quickly disintegrate when immersed in water.Therefore,keeping the original structure of the variegated clay slope soil undisturbed,and avoiding the evaporation of soil moisture on the surface layer of the slope is an effective way to slow down the collapse of the variegated clay slope.(2)The results of laboratory disintegration tests show that with the increase of the initial water content,the amount and rate of disintegration of the sample gradually decrease.The effect of dry-wet cycle on the disintegration of the sample mainly manifests in the influence of the disintegration rate of the soil.The effect of the sample size on the disintegration behavior is the same as that achieved by the restriction of the outer soil on the inner soil.(3)The grey correlation theory was used to calculate the correlation between the micro pore parameters of the variegated clay and the disintegration parameters.It was found that there was a certain degree of correlation between the average pore diameter,the area-to-pore ratio,the fractal fractal dimension of the pore shape,and the amount of disintegration..Pore fractal dimension has the highest correlation.The surface void ratio is the second,and the average pore diameter correlation is the lowest.(4)According to the difference of the disintegrated form of the variegated clay sample after immersion in water.The mechanism of softening and disintegration of variegated clay can be summarized as the disintegration and destruction forms mainly based on the swelling and compression of swelling minerals and the disintegration and failure forms mainly based on the softening of intergranular cementitious substances.