Experimental Study On Wetting Deformation Characteristics And Permeability Of Fissured Loess

Loess is widely distributed in China with heterogeneous characteristics,joints and fissures are w idely developed in soil,which makes its physical and mechanical properties anisotropic.Therefore,it is of great significance to study the engineering properties of the fissured loess.In this paper,the permeability and humidification characteristics of cracked loess are studied by triaxial test,static soil column test and dynamic soil column test.Through triaxial test,the difference of the influence of pre-wetting method and humidification method on the humidification deformation of remolded loess was studied,the influence of confining pressure and moisture content on the evolution characteristics of the stress-strain relationship of remolded loess was analyzed,and the influence mechanism of confining pressure and moisture content on the humidification deformation of remolded loess under different sample preparation methods was explored The test results show that the stress and strain curves of the remolded loess prepared by prehumidification and humidification are hardening.The test results show that the stress and strain curves of the remolded loess prepared by prehumidification and humidification are hardening.Contrast found that low moisture content when the humidifying the wet method of soil prepared by the stress strain curve of the hardening degree is larger,high moisture content condition sclerosis type curve is relatively close,reveals the hardening degree under different sample preparation method with the confining pressure increases,decreases with increasing moisture content,the change rule of as one-dimensional soil column and water penetration test sample preparation provides the basis.Based on static water seepage under the condition of soil column experiment,studies the crack depth,article number,width and pressure influence on fracture loess infiltration characteristics,analyzes the seepage flow,volume moisture content and suction with the changing rule of the soil column height and time,explores the crack depth,article number,width and volume moisture content and the suction pressure and seepage flow,the correlation between,The mechanism that the water infiltration rate increases with the increase of any variable among the crack depth,number and width and decreases with the increase of pressure is expounded.The study found that the crack depth and water infiltration rate,a good index relationship between crack width and water infiltration rate showed a good power function relationship between the vertical better conform to the logarithmic relationship between stress and strain,established the crack depth,breadth,and the number and the seepage flow,the mathematical expressions between found crack width influence on seepage flow,the largest crack of several times,The crack depth has little effect on it.The vibration under the condition of soil column water penetration test,the vibration excitations,amplitude and frequency on the with and without the influence of the fissure permeability of loess,analyzed the different vibration conditions in loess seepage flow,volume moisture content and suction change characteristics,explores the vibration excitations,the amplitude and frequency and seepage flow and the correlation between volume moisture content and suction.It is found that with the increase of any one of the three vibration factors,the disturbance energy of soil increases and the water infiltration rate increases,which reveals the mechanism of vibration infiltration.The mathematical expression between vibration frequency and amplitude and seepage flow rate is established.It is found that vibration frequency is more sensitive to seepage flow than vibration amplitude.In conclusion,this paper explored the mechanical properties of remolding loess and the permeability characteristics of cracked loess by different sample preparation methods through laboratory tests,which provided a reference for the laboratory to prepare soil samples by different sample preparation methods,and also provided a theoretical basis for solving the permeability problems of cracked loess in practical engineering.