Studying On Crushing Mechanism And Permeability Of Mudstone Granules Under Wet-dry Cycling

The sand and mudstone granules in the Three Gorges reservoir area were selected as the research object,and the permeation consolidation test and the particle sieving test were carried out under the combined action of load and dry and wet circulation.The results showed that the overburden load,soil dry density and coarse particle content were the influencing factors.The test system consists of plexiglass test barrel,upstream water supply device,downstream effluent device,heat source air inlet device,weight,measuring equipment(upper and lower head pressure measuring tube,dial indicator,downstream Collection tank,high-precision test balance)composition.Through the analysis and comparison of the test data,the conclusions and research results are:(1)Under the action of dry and wet cycle,the effects of dry density,overburden load and coarse particle content on mudstone granules were studied,and the variation law of mudstone permeability and consolidation characteristics under dry and wet cycle was summarized.The variation of the permeability of the bank slope soil will inevitably affect the seepage field of the bank slope.By analyzing the change of the permeability coefficient of the soil slope of 0.5m,1m,2m and 3m,the stability of the slope influences.Based on the change of void ratio and permeability coefficient of mudstone soil samples,the crushing mechanism of mudstone particle disintegration and crushing was revealed by Kozeny-Carman formula.Under the effect of wet and dry circulation,the mudstone is affected by the consolidation and crushing action at the same time.The consolidation effect is the main effect in the early stage of the experiment,and the main consolidation effect is dominated by the particle crushing.(2)By comparing the contents of the granule in the granule granule before and after the test,it was found that 2 ~ 5mm was the largest increase in the particle content,2 ~ 5mm as the characteristic particle size group,measure the crushing performance of coarse particles.The effect of dry density,overburden load and coarse particle content on the crushing degree of mudstone granules under dry and wet cycle was studied by using the hardin fracture potential Bp to quantify the gradation of mudstone particles before and after the experiment.Based on the entropy increasing principle,the granulite particle gradation is quantified by using the basic entropy NB,and the evolution model of the mudstone granule is established.The permeability coefficient K and the base entropy NB are fitted to find that the permeability coefficient K has a good relationship with the basic entropy NB Correlation,can be reflected through the soil permeability coefficient of particles in the dry and wet under the action of the broken situation(3)The seepage stability of sand and shale rock bank slope is discussed.It is found that with the increase of water level rise and fall,the pore average diameter of sand and mud mixture decreases gradually,which is smaller than that of mixture The particle size of the diameter Do is increasing.The relationship between the basal entropy NB and the fine particle content of the average pore diameter of the soil is established.The method of predicting the osmotic damage of the sand and shale bank is proposed by the basic entropy NB,and the stability of the bank slope Impact.