Study On Performance Of Improved Predisintegrated Carbonaceous Mudstone And Stability Of Embankment

Carbonaceous mudstones are widely distributed in southwestern China and central and western Hunan.They have good mechanical properties under dry conditions,strength of up to 60 MPa,and rock-related properties.During the construction process,it is inevitable that China’s planned new highways and railways will pass through the area of carbonaceous mudstone distribution.Considering engineering quantity and environmental protection,rational use of it and its use in embankment filling are the best engineering implementation solutions.Therefore,in this paper,the carbonaceous mudstone is easily disintegrated and softened when it encounters water.The static triaxial test,the unconfined compressive strength test,the permeability characteristic test,and the numerical simulation analysis of the improved pre-disintegrated carbonaceous mudstone-filled embankment were analyzed.The main research conclusions are as follows:(1)After the improvement of the pre-disintegrated carbonaceous mudstone,its cohesive force is significantly increased and its shear strength is increased;when the triaxial test is performed,there will be two cases of sudden stress deformation and stress softening deformation,and with the amount of cement and fly ash The more obvious the sudden change of stress is.(2)The uniaxial compressive strength of the pre-disintegrated carbonaceous mudstone is significantly improved after the improvement.The effects of the three improved materials on the unconfined compressive strength of the pre-disintegrated carbonaceous mudstone are cement,red clay,and fly ash.(3)After the improvement of the pre-disintegrated carbonaceous mudstone,its permeability coefficient decreased significantly.The relationship between the three modified materials affecting the permeability coefficient of the pre-disintegrated carbonaceous mudstone was cement,red clay,and fly ash.(4)It can be seen that the slope stability coefficient of the pre-disintegrated carbonaceous mudstone-filled embankment under the best improvement scheme under different rainfall intensities and rainfall times can be known.With the increase of rainfall time,the stability coefficient shows an increase and then a decrease The small change trend and the minimum stability coefficient are above the critical safety coefficient of the slope.